(4) Subtract the reference C3H8 mass from the calculated mass.  If this difference is within +-2 % of the reference mass, all PFD flow measurements for determining PFD dilution ratio pass this verification.  If not, take corrective action as described in paragraph (f) of this section.  For PFDs sampling only for PM, the allowed difference is +-5 %.
(h) Table 2 of §1065.307 describes optional verification procedures you may perform instead of linearity verification for certain flow-measurement systems.  Performing carbon balance error verification also replaces any required propane checks.

334. Amend §1065.342 by revising paragraph (d)(2) to read as follows:
§1065.342  Sample dryer verification.
*	*	*	*	*
(d)	*	*	*
(2) Humidify room air, purified N2, or purified air by bubbling it through distilled H2O in a sealed vessel or use a device that injects distilled H2O as vapor into a controlled gas flow to humidify the gas to the highest sample H2O content that you estimate during emission sampling.
*	*	*	*	*

335. Amend §1065.350 by revising paragraph (d)(2) to read as follows:
§1065.350  H2O interference verification for CO2 NDIR analyzers.
*	*	*	*	*
(d)	*	*	*
(2) Create a humidified test gas by bubbling zero gas that meets the specifications in §1065.750 through distilled H2O in a sealed vessel or use a device that introduces distilled H2O as vapor into a controlled gas flow.  If the sample does not pass through a dryer during emission testing, humidify your test gas to an H2O level at or above the maximum expected during emission testing.  If the sample passes through a dryer during emission testing, you must humidify your test gas to an H2O level at or above the level determined in §1065.145(e)(2) for that dryer.
*	*	*	*	*

336. Amend §1065.355 by revising paragraph (d)(2) to read as follows:
§1065.355  H2O and CO2 interference verification for CO NDIR analyzers.
*	*	*	*	*
(d)	*	*	*
(2) Create a humidified CO2 test gas by bubbling a CO2 span gas that meets the specifications in §1065.750 through distilled H2O in a sealed vessel or use a device that introduces distilled H2O as vapor into a controlled gas flow.  If the sample does not pass through a dryer during emission testing, humidify your test gas to an H2O level at or above the maximum expected during emission testing.  If the sample passes through a dryer during emission testing, you must humidify your test gas to an H2O at or above the level determined in §1065.145(e)(2) for that dryer.  Use a CO2 span gas concentration at least as high as the maximum expected during testing.
*	*	*	*	*

337. Amend §1065.360 by adding paragraphs (a)(4) and (d)(12) to read as follows:
§1065.360  FID optimization and verification.
(a)	*	*	*
(4) For any gaseous-fueled engine, including dual-fuel and flexible-fuel engines, you may determine the methane (CH4) and ethane (C2H6) response factors as a function of the molar water concentration in the raw or diluted exhaust.  If you choose this option, generate and verify the humidity level (or fraction) as described in §1065.365(d)(11).
*	*	*	*	*
(d)	*	*	*
(12) Determine the response factor as a function of molar water concentration and use this response factor to account for the CH4 response for NMHC determination described in §1065.660(b)(2)(iii).  Humidify the CH4 span gas as described in §1065.365(d)(11) and repeat the steps in paragraphs (d)(7) through (9) of this section until measurements are complete for each setpoint in the selected range.  Divide each mean measured CH4 concentration by the recorded span concentration of the CH4 calibration gas, adjusted for water content, to determine the FID analyzer's CH4 response factor, RFCH4[THC-FID].  Use the CH4 response factors at the different setpoints to create a functional relationship between response factor and molar water concentration, downstream of the last sample dryer if any sample dryers are present.  Use this functional relationship to determine the response factor during an emission test.
*	*	*	*	*

338. Amend §1065.365 by revising paragraphs (a), (d), (f)(9), and (f)(14) to read as follows:
§1065.365  Nonmethane cutter penetration fractions.
(a) Scope and frequency.  If you use a FID analyzer and a nonmethane cutter (NMC) to measure methane (CH4), determine the nonmethane cutter's penetration fractions of methane, PFCH4, and ethane, PFC2H6.  As detailed in this section, these penetration fractions may be determined as a combination of NMC penetration fractions and FID analyzer response factors, depending on your particular NMC and FID analyzer configuration.  Perform this verification after installing the nonmethane cutter.  Repeat this verification within 185 days of testing to verify that the catalytic activity of the cutter has not deteriorated.  Note that because nonmethane cutters can deteriorate rapidly and without warning if they are operated outside of certain ranges of gas concentrations and outside of certain temperature ranges, good engineering judgment may dictate that you determine a nonmethane cutter's penetration fractions more frequently.
*	*	*	*	*
(d) Procedure for a FID calibrated with the NMC.  The method described in this paragraph (d) is recommended over the procedures specified in paragraphs (e) and (f) of this section and required for any gaseous-fueled engine, including dual-fuel and flexible-fuel engines.  If your FID arrangement is such that a FID is always calibrated to measure CH4 with the NMC, then span that FID with the NMC using a CH4 span gas, set the product of that FID's CH4 response factor and CH4 penetration fraction, RFPFCH4[NMC-FID], equal to 1.0 for all emission calculations, and determine its combined C2H6 response factor and C2H6 penetration fraction, RFPFC2H6[NMC-FID], as follows.  For any gaseous-fueled engine, including dual-fuel and flexible-fuel engines, you must determine the CH4 penetration fraction, PFCH4[NMC-FID], and C2H6 response factor and C2H6 penetration fraction, RFPFC2H6[NMC-FID], as a function of the molar water concentration in the raw or diluted exhaust as described in paragraphs (d)(10) and (12) of this section.  Generate and verify the humidity generation as described in §1065.365(d)(11).  When using this option, note that the FID's CH4 penetration fraction, PFCH4[NMC-FID], is set equal to 1.0 only for 0 % molar water concentration.  You are not required to meet the recommended lower limit for PFCH4 of greater than 0.85 for any of the penetration fractions generated as a function of molar water concentration.
(1) Select CH4 and C2H6 analytical gas mixtures and ensure that both mixtures meet the specifications of §1065.750.  Select a CH4 concentration that you would use for spanning the FID during emission testing and select a C2H6 concentration that is typical of the peak NMHC concentration expected at the hydrocarbon standard or equal to the THC analyzer's span value.  For CH4 analyzers with multiple ranges, perform this procedure on the highest range used for emission testing.
(2) Start, operate, and optimize the nonmethane cutter according to the manufacturer's instructions, including any temperature optimization.
(3) Confirm that the FID analyzer meets all the specifications of §1065.360.
(4) Start and operate the FID analyzer according to the manufacturer's instructions.
(5) Zero and span the FID with the nonmethane cutter as you would during emission testing.  Span the FID through the cutter by using CH4 span gas.
(6) Introduce the C2H6 analytical gas mixture upstream of the nonmethane cutter.  Use good engineering judgment to address the effect of hydrocarbon contamination if your point of introduction is vastly different from the point of zero/span gas introduction.
(7) Allow time for the analyzer response to stabilize.  Stabilization time may include time to purge the nonmethane cutter and to account for the analyzer's response.
(8) While the analyzer measures a stable concentration, record 30 seconds of sampled data.  Calculate the arithmetic mean of these data points.
(9) Divide the mean C2H6 concentration by the reference concentration of C2H6, converted to a C1 basis.  The result is the C2H6 combined response factor and penetration fraction, RFPFC2H6[NMC-FID].  Use this combined C2H6 response factor and C2H6 penetration fraction and the product of the CH4 response factor and CH4 penetration fraction, RFPFCH4[NMC-FID], set to 1.0 in emission calculations according to §1065.660(b)(2)(i), §1065.660(d)(1)(i), or §1065.665, as applicable.
(10) Determine the combined C2H6 response factor and C2H6 penetration fraction as a function of molar water concentration and use it to account for C2H6 response factor and C2H6 penetration fraction for NMHC determination as described in §1065.660(b)(2)(iii) and for CH4 determination in §1065.660(d)(1)(iii).  Humidify the C2H6 analytical gas mixture as described in paragraph (d)(11) of this section.  Repeat the steps in paragraphs (d)(6) through (8) of this section until measurements are complete for each setpoint in the selected range.  Divide each mean measured C2H6 concentration by the reference concentration of C2H6, converted to a C1-basis and adjusted for water content to determine the FID analyzer's combined C2H6 response factor and C2H6 penetration fraction, RFPFC2H6[NMC-FID].  Use RFPFC2H6[NMC-FID] at the different setpoints to create a functional relationship between the combined response factor and penetration fraction and molar water concentration, downstream of the last sample dryer if any sample dryers are present.  Use this functional relationship to determine the combined response factor and penetration fraction during the emission test.
(11) Create a humidified test gas by bubbling the analytical gas mixture that meets the specifications in §1065.750 through distilled H2O in a sealed vessel or use a device that introduces distilled H2O as vapor into a controlled gas flow.  If the sample does not pass through a dryer during emission testing, generate at least five different H2O concentrations that cover the range from less than the minimum expected to greater than the maximum expected water concentration during testing.  Use good engineering judgment to determine the target concentrations.  For analyzers where the sample passes through a dryer during emission testing, humidify your test gas to an H2O level at or above the level determined in §1065.145(e)(2) for that dryer and determine a single wet analyzer response to the dehumidified sample.  Heat all transfer lines from the water generation system to a temperature at least 5 °C higher than the highest dewpoint generated.  Determine H2O concentration as an average value over intervals of at least 30 seconds.  Monitor the humidified sample stream with a dewpoint analyzer, relative humidity sensor, FTIR, NDIR, or other water analyzer during each test or, if the humidity generator achieves humidity levels with controlled flow rates, validate the instrument within 370 days before testing and after major maintenance using one of the following methods:
(i) Determine the linearity of each flow metering device.  Use one or more reference flow meters to measure the humidity generator's flow rates and verify the H2O level value based on the humidity generator manufacturer's recommendations and good engineering judgment.  We recommend that you utilize at least 10 flow rates for each flow-metering device.
(ii) Perform validation testing based on monitoring the humidified stream with a dewpoint analyzer, relative humidity sensor, FTIR, NDIR, or other water analyzer as described in this paragraph (d)(11).  Compare the measured humidity to the humidity generator's value.  Verify overall linearity performance for the generated humidity as described in §1065.307 using the criteria for other dewpoint measurements or confirm all measured values are within +- 2 % of the target mole fraction.  In the case of dry gas, the measured value may not exceed 0.002 mole fraction.
(iii) Follow the performance requirements in §1065.307(b) if the humidity generator does not meet validation criteria.
(12) Determine the CH4 penetration fraction as a function of molar water concentration and use this penetration fraction for NMHC determination in §1065.660(b)(2)(iii) and for CH4 determination in §1065.660(d)(1)(iii).  Repeat the steps in paragraphs (d)(6) through (11) of this section, but with the CH4 analytical gas mixture instead of C2H6.  Use this functional relationship to determine the penetration fraction during the emission test.
*	*	*	*	*
(f)	*	*	*
(9) Divide the mean C2H6 concentration by the reference concentration of C2H6, converted to a C1 basis.  The result is the combined C2H6 response factor and C2H6 penetration fraction, RFPFC2H6[NMC-FID].  Use this combined C2H6 response factor and C2H6 penetration fraction according to §1065.660(b)(2)(iii), §1065.660(d)(1)(iii), or §1065.665, as applicable.
*	*	*	*	*
(14) Divide the mean CH4 concentration measured through the nonmethane cutter by the mean CH4 concentration measured after bypassing the nonmethane cutter.  The result is the CH4 penetration fraction, PFCH4[NMC-FID].  Use this CH4 penetration fraction according to §1065.660(b)(2)(iii), §1065.660(d)(1)(iii), or §1065.665, as applicable.

339. Amend §1065.370 by revising paragraph (e)(5) to read as follows:
§1065.370  CLD CO2 and H2O quench verification.
*	*	*	*	*
(e)	*	*	*
(5) Create a humidified NO span gas by bubbling a NO gas that meets the specifications in §1065.750 through distilled H2O in a sealed vessel or use a device that introduces distilled H2O as vapor into a controlled gas flow.  If the sample does not pass through a dryer during emission testing, humidify your test gas to an H2O level approximately equal to the maximum mole fraction of H2O expected during emission testing.  If the humidified NO span gas sample does not pass through a sample dryer, the quench verification calculations in §1065.675 scale the measured H2O quench to the highest mole fraction of H2O expected during emission testing.  If the sample passes through a dryer during emission testing, you must humidify your test gas to an H2O level at or above the level determined in §1065.145(e)(2) for that dryer.  For this case, the quench verification calculations in §1065.675 do not scale the measured H2O quench.
*	*	*	*	*

340. Amend §1065.375 by revising paragraph (d)(2) to read as follows:
§1065.375  Interference verification for N2O analyzers.
*	*	*	*	*
(d)	*	*	*
(2) Create a humidified test gas by bubbling a multi component span gas that incorporates the target interference species and meets the specifications in §1065.750 through distilled H2O in a sealed vessel or use a device that introduces distilled H2O as vapor into a controlled gas flow.  If the sample does not pass through a dryer during emission testing, humidify your test gas to an H2O level at or above the maximum expected during emission testing.  If the sample passes through a dryer during emission testing, you must humidify your test gas to an H2O level at or above the level determined in §1065.145(e)(2) for that dryer.  Use interference span gas concentrations that are at least as high as the maximum expected during testing.
*	*	*	*	*

341. Amend §1065.410 by revising paragraphs (c) and (d) to read as follows:
§1065.410  Maintenance limits for stabilized test engines.
*	*	*	*	*
(c) If you inspect an engine, keep a record of the inspection and update your application for certification to document any changes that result.  You may use any kind of equipment, instrument, or tool that is available at dealerships and other service outlets to identify malfunctioning components or perform maintenance.
(d) You may repair defective parts from a test engine if they are unrelated to emission control. You must ask us to approve repairs that might affect the engine's emission controls.  If we determine that a part failure, system malfunction, or associated repair makes the engine's emission controls unrepresentative of production engines, you may not use it as an emission-data engine.  Also, if your test engine has a major mechanical failure that requires you to take it apart, you may no longer use it as an emission-data engine.

342. Amend §1065.510 by -
a. Revising paragraphs (a) introductory text and (b)(5)(i).
b. Adding paragraph (c)(5).
c. Revising paragraph (f)(4)(i)
The revisions and addition read as follows:
§1065.510  Engine mapping.
(a) Applicability, scope, and frequency.  An engine map is a data set that consists of a series of paired data points that represent the maximum brake torque versus engine speed, measured at the engine's primary output shaft.  Map your engine if the standard-setting part requires engine mapping to generate a duty cycle for your engine configuration.  Map your engine while it is connected to a dynamometer or other device that can absorb work output from the engine's primary output shaft according to §1065.110.  Configure any auxiliary work inputs and outputs such as hybrid, turbo-compounding, or thermoelectric systems to represent their in-use configurations, and use the same configuration for emission testing.  See Figure 1 of §1065.210. This may involve configuring initial states of charge and rates and times of auxiliary-work inputs and outputs.  We recommend that you contact the Designated Compliance Officer before testing to determine how you should configure any auxiliary-work inputs and outputs.  Use the most recent engine map to transform a normalized duty cycle from the standard-setting part to a reference duty cycle specific to your engine.  Normalized duty cycles are specified in the standard-setting part. You may update an engine map at any time by repeating the engine-mapping procedure.  You must map or re-map an engine before a test if any of the following apply:
*	*	*	*	*
(b)	*	*	*
(5) 	*	*	*
(i) For any engine subject only to steady-state duty cycles, you may perform an engine map by using discrete speeds.  Select at least 20 evenly spaced setpoints from 95 % of warm idle speed to the highest speed above maximum power at which 50 % of maximum power occurs.  We refer to this 50 % speed as the check point speed as described in paragraph (b)(5)(iii) of this section.  At each setpoint, stabilize speed and allow torque to stabilize.  We recommend that you stabilize an engine for at least 15 seconds at each setpoint and record the mean feedback speed and torque of the last (4 to 6) seconds.  Record the mean speed and torque at each setpoint.  Use linear interpolation to determine intermediate speeds and torques.  Use this series of speeds and torques to generate the power map as described in paragraph (e) of this section.
*	*	*	*	*
(c)	*	*	*
(5) For engines with an electric hybrid system, map the negative torque required to motor the engine by repeating paragraph (b) of this section with minimum operator demand and a fully charged RESS or with the hybrid system disabled, such that it doesn't affect the motoring torque. You may start the negative torque map at either the minimum or maximum speed from paragraph (b) of this section.
*	*	*	*	*
(f)	*	*
(4)	*	*	*
(i) For variable-speed engines, declare a warm idle torque that is representative of in-use operation.  For example, if your engine is typically connected to an automatic transmission or a hydrostatic transmission, declare the torque that occurs at the idle speed at which your engine operates when the transmission is engaged.  Use this value for cycle generation.  You may use multiple warm idle torques and associated idle speeds in cycle generation for representative testing.  For example, for cycles that start the engine and begin with idle, you may start a cycle in idle with the transmission in neutral with zero torque and later switch to a different idle with the transmission in drive with the Curb-Idle Transmission Torque (CITT).  For variable-speed engines intended primarily for propulsion of a vehicle with an automatic transmission where that engine is subject to a transient duty cycle with idle operation, you must declare a CITT.  We recommend that you specify CITT as a function of idle speed for engines with adjustable warm idle or enhanced-idle.  You may specify a CITT based on typical applications at the mean of the range of idle speeds you specify at stabilized temperature conditions.
*	*	*	*	*

343. Amend §1065.512 by revising paragraphs (b)(1) and (2) to read as follows:
§1065.512  Duty cycle generation.
*	*	*	*	*
(b)	*	*	*
(1) Engine speed for variable-speed engines.  For variable-speed engines, normalized speed may be expressed as a percentage between warm idle speed, fnidle, and maximum test speed, fntest, or speed may be expressed by referring to a defined speed by name, such as "warm idle," "intermediate speed," or "A," "B," or "C" speed.  Section 1065.610 describes how to transform these normalized values into a sequence of reference speeds, fnref.  Running duty cycles with negative or small normalized speed values near warm idle speed may cause low-speed idle governors to activate and the engine torque to exceed the reference torque even though the operator demand is at a minimum.  In such cases, we recommend controlling the dynamometer so it gives priority to follow the reference torque instead of the reference speed and let the engine govern the speed.  Note that the cycle-validation criteria in §1065.514 allow an engine to govern itself.  This allowance permits you to test engines with enhanced-idle devices and to simulate the effects of transmissions such as automatic transmissions.  For example, an enhanced-idle device might be an idle speed value that is normally commanded only under cold-start conditions to quickly warm up the engine and aftertreatment devices.  In this case, negative and very low normalized speeds will generate reference speeds below this higher enhanced-idle speed. You may do either of the following with when using enhanced-idle devices:
(i) Control the dynamometer so it gives priority to follow the reference torque, controlling the operator demand so it gives priority to follow reference speed and let the engine govern the speed when the operator demand is at minimum.
(ii) While running an engine where the electronic control module broadcasts an enhanced-idle speed that is above the denormalized speed, use the broadcast speed as the reference speed. Use these new reference points for duty-cycle validation. This does not affect how you determine denormalized reference torque in paragraph (b)(2) of this section.
(2) Engine torque for variable-speed engines.  For variable-speed engines, normalized torque is expressed as a percentage of the mapped torque at the corresponding reference speed.  Section 1065.610 describes how to transform normalized torques into a sequence of reference torques, Tref.  Section 1065.610 also describes special requirements for modifying transient duty cycles for variable-speed engines intended primarily for propulsion of a vehicle with an automatic transmission.  Section 1065.610 also describes under what conditions you may command Tref greater than the reference torque you calculated from a normalized duty cycle.  This provision permits you to command Tref values that are limited by a declared minimum torque.  For any negative torque commands, command minimum operator demand and use the dynamometer to control engine speed to the reference speed, but if reference speed is so low that the idle governor activates, we recommend using the dynamometer to control torque to zero, CITT, or a declared minimum torque as appropriate.  Note that you may omit power and torque points during motoring from the cycle-validation criteria in §1065.514. Also, use the maximum mapped torque at the minimum mapped speed as the maximum torque for any reference speed at or below the minimum mapped speed.
*	*	*	*	*

344. Amend §1065.514 by revising paragraphs (e) introductory text, (e)(3), and (f)(3) to read as follows:
§1065.514  Cycle-validation criteria for operation over specified duty cycles.
*	*	*	*	*
(e) Statistical parameters.  Use the remaining points to calculate regression statistics for a floating intercept as described in §1065.602.  Round calculated regression statistics to the same number of significant digits as the criteria to which they are compared.  Refer to Table 2 of §1065.514 for the default criteria and refer to the standard-setting part to determine if there are other criteria for your engine.  Calculate the following regression statistics:
*	*	*	*	*
(3) Standard error of the estimate for feedback speed, SEEfn, feedback torque, SEET, and feedback power SEEP.
*	*	*	*	*
(f)	*	*	*
(3) For discrete-mode steady-state testing, apply cycle-validation criteria by treating the sampling periods from the series of test modes as a continuous sampling period, analogous to ramped-modal testing and apply statistical criteria as described in paragraph (f)(1) or (f)(2) of this section.  Note that if the gaseous and particulate test intervals are different periods of time, separate validations are required for the gaseous and particulate test intervals.  Table 2 follows:
Table 2 of §1065.514 -- Default Statistical Criteria for Validating Duty Cycles
                                   Parameter
                                     Speed
                                    Torque
                                     Power
Slope, a1
                            0.950 <= a1 <= 1.030
                            0.830 <= a1 <= 1.030
                            0.830 <= a1 <= 1.030
Absolute value of intercept, |a0|
                             <= 10 % of warm idle
                       <= 2 % of maximum mapped torque
                        <= 2 % of maximum mapped power
Standard error of the estimate, SEE
                         <= 5 % of maximum test speed
                       <= 10 % of maximum mapped torque
                       <= 10 % of maximum mapped power
Coefficient of determination, r[2]
                                   >= 0.970
                                   >= 0.850
                                   >= 0.910

345. Amend §1065.530 by revising paragraphs (a)(2)(iii) and (g)(5) to read as follows:
§1065.530  Emission test sequence.
(a)	*	*	*
(2)	*	*	*
(iii) For testing that involves hot-stabilized emission measurements, bring the engine either to warm idle or the first operating point of the duty cycle.  Start the test within 10 min of achieving temperature stability.  Determine temperature stability as the point at which the engine thermostat controls engine temperature or as the point at which measured operating temperature has stayed within +-2 % of the mean value for at least 2 min based on the following parameters:
(A) Engine coolant or block or head absolute temperatures for water-cooled engines.
(B) Oil sump absolute temperature for air-cooled engines with an oil sump.
(C) Cylinder head absolute temperature or exhaust gas temperature for air-cooled engines with no oil sump.
*	*	*	*	*
(g)	*	*	*
(5) If you perform carbon balance error verification, verify carbon balance error as specified in the standard-setting part and §1065.543.  Calculate and report the three carbon balance error quantities for each test interval; carbon mass absolute error for a test interval (ϵaC), carbon mass rate absolute error for a test interval (ϵaCrate), and carbon mass relative error for a test interval (ϵrC).  For duty cycles with multiple test intervals, you may calculate and report the composite carbon mass relative error, ϵrCcomp, for the whole duty cycle.  If you report ϵrCcomp, you must still calculate and report ϵaC, ϵaCrate, and ϵrC for each test interval.
*	*	*	*	*

346. Add §1065.543 to read as follows:
§1065.543  Carbon balance error verification.
(a) Carbon balance error verification compares independently calculated quantities of carbon flowing into and out of an engine system. The engine system includes aftertreatment devices as applicable. Calculating carbon intake considers carbon-carrying streams flowing into the system, including intake air, fuel, and optionally DEF or other fluids.  Carbon flow out of the system comes from exhaust emission calculations.  Note that this verification is not valid if you calculate exhaust molar flow rate using fuel rate and chemical balance as described in §1065.655(f)(3) because carbon flows into and out of the system are not independent.  Use good engineering judgment to ensure that carbon mass in and carbon mass out data signals align.
(b) Perform the carbon balance error verification after emission sampling is complete for a test interval or duty cycle as described in §1065.530(g).  Testing must include measured values as needed to determine intake air, fuel flow, and carbon-related gaseous exhaust emissions.  You may optionally account for the flow of carbon-carrying fluids other than intake air and fuel into the system.
Perform carbon balance error verification as follows:
(1) Calculate carbon balance error quantities as described in §1065.643.  The three quantities for individual test intervals are carbon mass absolute error, ϵaC, carbon mass rate absolute error, ϵaCrate, and carbon mass relative error, ϵrC.  Determine ϵaC, ϵaCrate, and ϵrC for all test intervals. You may determine composite carbon mass relative error, ϵrCcomp, as a fourth quantity that optionally applies for duty cycles with multiple test intervals.
(2) You meet verification criteria for an individual test interval if the absolute values of carbon balance error quantities are at or below the following limit values:
(i) Calculate the carbon mass absolute error limit, LϵaC, in grams to three decimal places for comparision to the absolute value of ϵaC, using the following equation:

      Eq. 1065.543-1
Where:
c = power-specific carbon mass absolute error coefficient = 0.007 g/kW.
Pmax = maximum power from the engine map generated according to §1065.510.  If measured Pmax is not available, use a manufacturer-declared value for Pmax.

Example:
c = 0.007 g/kW
Pmax = 230.0 kW

(ii) Calculate the carbon mass rate absolute error limit, LϵaCrate, in grams per hour to three decimal places for comparison to the absolute value of ϵaCrate, using the following equation:

Eq. 1065.543-2
Where:
d = power-specific carbon mass rate absolute error coefficient = 0.31 g/(kW∙hr).
Pmax = maximum power from the engine map generated according to §1065.510.  If measured Pmax is not available, use a manufacturer-declared value for Pmax.

Example:
d = 0.31 g/(kW∙hr)
Pmax = 230.0 kW

(iii) The carbon mass relative error limit, LϵrC , is 0.020 for comparision to the absolute value of ϵrC, and optionally the absolute value of ϵrCcomp.
(c) A failed carbon balance error verification might indicate one or more problems requiring corrective action, as follows:
                                Area of Concern
                                    Problem
                         Recommended Corrective Action
Gas analyzer system
Incorrect analyzer calibration
Calibrate NDIR and THC analyzers.

Incorrect time alignment between flow and concentration data
Determine transformation time, t50, for continuous gas analyzers and time-align flow and concentration data as described in §1065.650(c)(2)(i).

Problems with the sample system
Inspect sample system components such as sample lines, filters, chillers, and pumps for leaks, operating temperature, and contamination.
Fuel flow measurement
Zero shift of fuel flow rate meter
Perform an in-situ zero adjustment.

Change in fuel flow meter calibration
Calibrate the fuel flow meter as described in §1065.320.

Incorrect time alignment of fuel flow data
Verify alignment of carbon mass in and carbon mass out data streams.

Short sampling periods
For test intervals with varying duration, such as discrete-mode steady-state duty cycles, make the test intervals longer to improve accuracy when measuring low fuel flow rates.

Fluctuations in the fuel conditioning system
Improve stability of the fuel temperature and pressure conditioning system to improve accuracy when measuring low fuel flow rates.
Dilute testing using a CVS system
Leaks
Inspect exhaust system and CVS tunnel, connections, and fasteners. Repair or replace components as needed.  A leak in the exhaust transfer tube to the CVS may result in negative values for carbon balance error.

Poor mixing
Perform the verification related to mixing in §1065.341(f).

Change in CVS calibration
Calibrate the CVS flow meter as described in §1065.340.

Flow meter entrance effects
Inspect the CVS tunnel to determine whether entrance effects from the piping configuration upstream of the flow meter adversely affect flow measurement.

Other problems with the CVS or sampling verification hardware or software
Inspect hardware and software for the CVS system and CVS verification system for discrepancies.
Raw testing using intake air flow measurement or direct exhaust flow measurement
Leaks
Inspect intake air and exhaust systems, connections, fasteners. Repair or replace components as needed.

Zero shift of intake air flow rate meter
Perform an in-situ zero adjustment.

Change in intake air flow meter calibration
Calibrate the intake air flow meter as described in §1065.325.

Zero shift of exhaust flow rate meter
Perform an in-situ zero adjustment.

Change in exhaust flow meter calibration
Calibrate the exhaust flow meter as described in §1065.330.

Flow meter entrance effects
Inspect intake air and exhaust systems to determine whether entrance effects from the piping configuration upstream and downstream of the intake air flow meter or the exhaust flow meter adversely affect flow measurement.

Other problems with the intake air flow and exhaust flow measurement hardware or software
Look for discrepancies in the hardware and software for measuring intake air flow and exhaust flow.

Poor mixing
Ensure that all streams are well mixed.
Accuracy of fluid properties
Inaccurate fluid properties
If defaults are used, use measured values.  If measured values are used, verify fluid property determination.

347. Amend §1065.545 by revising paragraphs (a) and (b) introductory text to read as follows:
§1065.545  Verification of proportional flow control for batch sampling.
*	*	*	*	*
(a) For any pair of flow rates, use recorded sample and total flow rates.  Total flow rate means the raw exhaust flow rate for raw exhaust sampling and the dilute exhaust flow rate for CVS sampling, or their 1 Hz means with the statistical calculations in §1065.602 forcing the intercept through zero.  Determine the standard error of the estimate, SEE, of the sample flow rate versus the total flow rate.  For each test interval, demonstrate that SEE was less than or equal to 3.5 % of the mean sample flow rate.
(b) For any pair of flow rates, use recorded sample and total flow rates.  Total flow rate means the raw exhaust flow rate for raw exhaust sampling and the dilute exhaust flow rate for CVS sampling, or their 1 Hz means to demonstrate that each flow rate was constant within +-2.5 % of its respective mean or target flow rate.  You may use the following options instead of recording the respective flow rate of each type of meter:
*	*	*	*	*

348. Revise §1065.602 to read as follows:
§1065.602  Statistics.
(a) Overview. This section contains equations and example calculations for statistics that are specified in this part.  In this section we use the letter "y" to denote a generic measured quantity, the superscript over-bar " -  " to denote an arithmetic mean, and the subscript "ref" to denote the reference quantity being measured.
(b) Arithmetic mean.  Calculate an arithmetic mean,, as follows:

                  Eq. 1065.602-1
Example:
N = 3
y1 = 10.60
y2 = 11.91
yN = y3 = 11.09

 = 11.20
(c) Standard deviation.  Calculate the standard deviation for a non-biased (e.g., N - 1) sample, σ, as follows:

                  Eq. 1065.602-2
Example:
N = 3
y1 = 10.60
y2 = 11.91
yN = y3 = 11.09
= 11.20

σy= 0.6619
(d) Root mean square.  Calculate a root mean square, rmsy, as follows:

                  Eq. 1065.602-3
Example:
N = 3
y1 = 10.60
y2 = 11.91
yN = y3 = 11.09

rmsy= 11.21
(e) Accuracy.  Determine accuracy as described in this paragraph (e).  Make multiple measurements of a standard quantity to create a set of observed values, yi, and compare each observed value to the known value of the standard quantity.  The standard quantity may have a single known value, such as a gas standard, or a set of known values of negligible range, such as a known applied pressure produced by a calibration device during repeated applications.  The known value of the standard quantity is represented by yrefi.  If you use a standard quantity with a single value,  would be constant.  Calculate an accuracy value as follows:

                  Eq. 1065.602-4
Example:
yref = 1800.0
N = 3
= 1806.4
= 1803.1
= 1798.9

accuracy = 2.8
(f) t-test.  Determine if your data passes a t-test by using the following equations and tables:
      (1) For an unpaired t-test, calculate the t statistic and its number of degrees of freedom, v, as follows:

                  Eq. 1065.602-5

                  Eq. 1065.602-6
Example:
= 1205.3
 = 1123.8
σref = 9.399
σy = 10.583
Nref = 11
N = 7

t = 16.63

σref = 9.399
σy = 10.583
Nref = 11
N = 7

 = 11.76
(2) For a paired t-test, calculate the t statistic and its number of degrees of freedom, v, as follows, noting that theare the errors (e.g., differences) between each pair of yrefi and yi:

                  Eq. 1065.602-7
Example:
=  - 0.12580
N = 16
 = 0.04837

t = 10.403
ν = N  -  1
Example:
N = 16
v = 16  -  1
v = 15
(3)  Use Table 1 of this section to compare t to the tcrit values tabulated versus the number of degrees of freedom.  If t is less than tcrit, then t passes the t-test.  The Microsoft Excel software has a TINV function that returns results equivalent results and may be used in place of Table 1, which follows:
                           Table 1 of §1065.602 -
          Critical t Values Versus Number of Degrees of Freedom, v[a]
                                       v
                                  Confidence

                                     90 %
                                     95 %
                                       1
                                     6.314
                                    12.706
                                       2
                                     2.920
                                     4.303
                                       3
                                     2.353
                                     3.182
                                       4
                                     2.132
                                     2.776
                                       5
                                     2.015
                                     2.571
                                       6
                                     1.943
                                     2.447
                                       7
                                     1.895
                                     2.365
                                       8
                                     1.860
                                     2.306
                                       9
                                     1.833
                                     2.262
                                      10
                                     1.812
                                     2.228
                                      11
                                     1.796
                                     2.201
                                      12
                                     1.782
                                     2.179
                                      13
                                     1.771
                                     2.160
                                      14
                                     1.761
                                     2.145
                                      15
                                     1.753
                                     2.131
                                      16
                                     1.746
                                     2.120
                                      18
                                     1.734
                                     2.101
                                      20
                                     1.725
                                     2.086
                                      22
                                     1.717
                                     2.074
                                      24
                                     1.711
                                     2.064
                                      26
                                     1.706
                                     2.056
                                      28
                                     1.701
                                     2.048
                                      30
                                     1.697
                                     2.042
                                      35
                                     1.690
                                     2.030
                                      40
                                     1.684
                                     2.021
                                      50
                                     1.676
                                     2.009
                                      70
                                     1.667
                                     1.994
                                      100
                                     1.660
                                     1.984
                                     1000+
                                     1.645
                                     1.960
[a]Use linear interpolation to establish values not shown here.

(g) F-test.  Calculate the F statistic as follows:

                  Eq. 1065.602-8
Example:

F = 1.268
(1) For a 90 % confidence F-test, use the following table to compare F to the Fcrit90 values tabulated versus (N - 1) and (Nref  - 1).  If F is less than Fcrit90, then F passes the F-test at 90 % confidence.

Table 2 of §1065.602 - Critical F Values, Fcrit90, versus N - 1 and Nref  - 1 at 90 % Confidence
                                     N - 1
                                       1
                                       2
                                       3
                                       4
                                       5
                                       6
                                       7
                                       8
                                       9
                                      10
                                      12
                                      15
                                      20
                                      24
                                      30
                                      40
                                      60
                                      120
                                     1000+
                                   Nref - 1

                                       1
                                     39.86
                                     49.50
                                     53.59
                                     55.83
                                     57.24
                                     58.20
                                     58.90
                                     59.43
                                     59.85
                                     60.19
                                     60.70
                                     61.22
                                     61.74
                                     62.00
                                     62.26
                                     62.52
                                     62.79
                                     63.06
                                     63.32
                                       2
                                     8.526
                                     9.000
                                     9.162
                                     9.243
                                     9.293
                                     9.326
                                     9.349
                                     9.367
                                     9.381
                                     9.392
                                     9.408
                                     9.425
                                     9.441
                                     9.450
                                     9.458
                                     9.466
                                     9.475
                                     9.483
                                     9.491
                                       3
                                     5.538
                                     5.462
                                     5.391
                                     5.343
                                     5.309
                                     5.285
                                     5.266
                                     5.252
                                     5.240
                                     5.230
                                     5.216
                                     5.200
                                     5.184
                                     5.176
                                     5.168
                                     5.160
                                     5.151
                                     5.143
                                     5.134
                                       4
                                     4.545
                                     4.325
                                     4.191
                                     4.107
                                     4.051
                                     4.010
                                     3.979
                                     3.955
                                     3.936
                                     3.920
                                     3.896
                                     3.870
                                     3.844
                                     3.831
                                     3.817
                                     3.804
                                     3.790
                                     3.775
                                     3.761
                                       5
                                     4.060
                                     3.780
                                     3.619
                                     3.520
                                     3.453
                                     3.405
                                     3.368
                                     3.339
                                     3.316
                                     3.297
                                     3.268
                                     3.238
                                     3.207
                                     3.191
                                     3.174
                                     3.157
                                     3.140
                                     3.123
                                     3.105
                                       6
                                     3.776
                                     3.463
                                     3.289
                                     3.181
                                     3.108
                                     3.055
                                     3.014
                                     2.983
                                     2.958
                                     2.937
                                     2.905
                                     2.871
                                     2.836
                                     2.818
                                     2.800
                                     2.781
                                     2.762
                                     2.742
                                     2.722
                                       7
                                     3.589
                                     3.257
                                     3.074
                                     2.961
                                     2.883
                                     2.827
                                     2.785
                                     2.752
                                     2.725
                                     2.703
                                     2.668
                                     2.632
                                     2.595
                                     2.575
                                     2.555
                                     2.535
                                     2.514
                                     2.493
                                     2.471
                                       8
                                     3.458
                                     3.113
                                     2.924
                                     2.806
                                     2.726
                                     2.668
                                     2.624
                                     2.589
                                     2.561
                                     2.538
                                     2.502
                                     2.464
                                     2.425
                                     2.404
                                     2.383
                                     2.361
                                     2.339
                                     2.316
                                     2.293
                                       9
                                     3.360
                                     3.006
                                     2.813
                                     2.693
                                     2.611
                                     2.551
                                     2.505
                                     2.469
                                     2.440
                                     2.416
                                     2.379
                                     2.340
                                     2.298
                                     2.277
                                     2.255
                                     2.232
                                     2.208
                                     2.184
                                     2.159
                                      10
                                     3.285
                                     2.924
                                     2.728
                                     2.605
                                     2.522
                                     2.461
                                     2.414
                                     2.377
                                     2.347
                                     2.323
                                     2.284
                                     2.244
                                     2.201
                                     2.178
                                     2.155
                                     2.132
                                     2.107
                                     2.082
                                     2.055
                                      11
                                     3.225
                                     2.860
                                     2.660
                                     2.536
                                     2.451
                                     2.389
                                     2.342
                                     2.304
                                     2.274
                                     2.248
                                     2.209
                                     2.167
                                     2.123
                                     2.100
                                     2.076
                                     2.052
                                     2.026
                                     2.000
                                     1.972
                                      12
                                     3.177
                                     2.807
                                     2.606
                                     2.480
                                     2.394
                                     2.331
                                     2.283
                                     2.245
                                     2.214
                                     2.188
                                     2.147
                                     2.105
                                     2.060
                                     2.036
                                     2.011
                                     1.986
                                     1.960
                                     1.932
                                     1.904
                                      13
                                     3.136
                                     2.763
                                     2.560
                                     2.434
                                     2.347
                                     2.283
                                     2.234
                                     2.195
                                     2.164
                                     2.138
                                     2.097
                                     2.053
                                     2.007
                                     1.983
                                     1.958
                                     1.931
                                     1.904
                                     1.876
                                     1.846
                                      14
                                     3.102
                                     2.726
                                     2.522
                                     2.395
                                     2.307
                                     2.243
                                     2.193
                                     2.154
                                     2.122
                                     2.095
                                     2.054
                                     2.010
                                     1.962
                                     1.938
                                     1.912
                                     1.885
                                     1.857
                                     1.828
                                     1.797
                                      15
                                     3.073
                                     2.695
                                     2.490
                                     2.361
                                     2.273
                                     2.208
                                     2.158
                                     2.119
                                     2.086
                                     2.059
                                     2.017
                                     1.972
                                     1.924
                                     1.899
                                     1.873
                                     1.845
                                     1.817
                                     1.787
                                     1.755
                                      16
                                     3.048
                                     2.668
                                     2.462
                                     2.333
                                     2.244
                                     2.178
                                     2.128
                                     2.088
                                     2.055
                                     2.028
                                     1.985
                                     1.940
                                     1.891
                                     1.866
                                     1.839
                                     1.811
                                     1.782
                                     1.751
                                     1.718
                                      17
                                     3.026
                                     2.645
                                     2.437
                                     2.308
                                     2.218
                                     2.152
                                     2.102
                                     2.061
                                     2.028
                                     2.001
                                     1.958
                                     1.912
                                     1.862
                                     1.836
                                     1.809
                                     1.781
                                     1.751
                                     1.719
                                     1.686
                                      18
                                     3.007
                                     2.624
                                     2.416
                                     2.286
                                     2.196
                                     2.130
                                     2.079
                                     2.038
                                     2.005
                                     1.977
                                     1.933
                                     1.887
                                     1.837
                                     1.810
                                     1.783
                                     1.754
                                     1.723
                                     1.691
                                     1.657
                                      19
                                     2.990
                                     2.606
                                     2.397
                                     2.266
                                     2.176
                                     2.109
                                     2.058
                                     2.017
                                     1.984
                                     1.956
                                     1.912
                                     1.865
                                     1.814
                                     1.787
                                     1.759
                                     1.730
                                     1.699
                                     1.666
                                     1.631
                                      20
                                     2.975
                                     2.589
                                     2.380
                                     2.249
                                     2.158
                                     2.091
                                     2.040
                                     1.999
                                     1.965
                                     1.937
                                     1.892
                                     1.845
                                     1.794
                                     1.767
                                     1.738
                                     1.708
                                     1.677
                                     1.643
                                     1.607
                                      21
                                     2.961
                                     2.575
                                     2.365
                                     2.233
                                     2.142
                                     2.075
                                     2.023
                                     1.982
                                     1.948
                                     1.920
                                     1.875
                                     1.827
                                     1.776
                                     1.748
                                     1.719
                                     1.689
                                     1.657
                                     1.623
                                     1.586
                                      22
                                     2.949
                                     2.561
                                     2.351
                                     2.219
                                     2.128
                                     2.061
                                     2.008
                                     1.967
                                     1.933
                                     1.904
                                     1.859
                                     1.811
                                     1.759
                                     1.731
                                     1.702
                                     1.671
                                     1.639
                                     1.604
                                     1.567
                                      23
                                     2.937
                                     2.549
                                     2.339
                                     2.207
                                     2.115
                                     2.047
                                     1.995
                                     1.953
                                     1.919
                                     1.890
                                     1.845
                                     1.796
                                     1.744
                                     1.716
                                     1.686
                                     1.655
                                     1.622
                                     1.587
                                     1.549
                                      24
                                     2.927
                                     2.538
                                     2.327
                                     2.195
                                     2.103
                                     2.035
                                     1.983
                                     1.941
                                     1.906
                                     1.877
                                     1.832
                                     1.783
                                     1.730
                                     1.702
                                     1.672
                                     1.641
                                     1.607
                                     1.571
                                     1.533
                                      25
                                     2.918
                                     2.528
                                     2.317
                                     2.184
                                     2.092
                                     2.024
                                     1.971
                                     1.929
                                     1.895
                                     1.866
                                     1.820
                                     1.771
                                     1.718
                                     1.689
                                     1.659
                                     1.627
                                     1.593
                                     1.557
                                     1.518
                                      26
                                     2.909
                                     2.519
                                     2.307
                                     2.174
                                     2.082
                                     2.014
                                     1.961
                                     1.919
                                     1.884
                                     1.855
                                     1.809
                                     1.760
                                     1.706
                                     1.677
                                     1.647
                                     1.615
                                     1.581
                                     1.544
                                     1.504
                                      27
                                     2.901
                                     2.511
                                     2.299
                                     2.165
                                     2.073
                                     2.005
                                     1.952
                                     1.909
                                     1.874
                                     1.845
                                     1.799
                                     1.749
                                     1.695
                                     1.666
                                     1.636
                                     1.603
                                     1.569
                                     1.531
                                     1.491
                                      28
                                     2.894
                                     2.503
                                     2.291
                                     2.157
                                     2.064
                                     1.996
                                     1.943
                                     1.900
                                     1.865
                                     1.836
                                     1.790
                                     1.740
                                     1.685
                                     1.656
                                     1.625
                                     1.593
                                     1.558
                                     1.520
                                     1.478
                                      29
                                     2.887
                                     2.495
                                     2.283
                                     2.149
                                     2.057
                                     1.988
                                     1.935
                                     1.892
                                     1.857
                                     1.827
                                     1.781
                                     1.731
                                     1.676
                                     1.647
                                     1.616
                                     1.583
                                     1.547
                                     1.509
                                     1.467
                                      30
                                     2.881
                                     2.489
                                     2.276
                                     2.142
                                     2.049
                                     1.980
                                     1.927
                                     1.884
                                     1.849
                                     1.819
                                     1.773
                                     1.722
                                     1.667
                                     1.638
                                     1.606
                                     1.573
                                     1.538
                                     1.499
                                     1.456
                                      40
                                     2.835
                                     2.440
                                     2.226
                                     2.091
                                     1.997
                                     1.927
                                     1.873
                                     1.829
                                     1.793
                                     1.763
                                     1.715
                                     1.662
                                     1.605
                                     1.574
                                     1.541
                                     1.506
                                     1.467
                                     1.425
                                     1.377
                                      60
                                     2.791
                                     2.393
                                     2.177
                                     2.041
                                     1.946
                                     1.875
                                     1.819
                                     1.775
                                     1.738
                                     1.707
                                     1.657
                                     1.603
                                     1.543
                                     1.511
                                     1.476
                                     1.437
                                     1.395
                                     1.348
                                     1.291
                                      120
                                     2.748
                                     2.347
                                     2.130
                                     1.992
                                     1.896
                                     1.824
                                     1.767
                                     1.722
                                     1.684
                                     1.652
                                     1.601
                                     1.545
                                     1.482
                                     1.447
                                     1.409
                                     1.368
                                     1.320
                                     1.265
                                     1.193
                                     1000+
                                     2.706
                                     2.303
                                     2.084
                                     1.945
                                     1.847
                                     1.774
                                     1.717
                                     1.670
                                     1.632
                                     1.599
                                     1.546
                                     1.487
                                     1.421
                                     1.383
                                     1.342
                                     1.295
                                     1.240
                                     1.169
                                     1.000

(2) For a 95 % confidence F-test, use the following table to compare F to the Fcrit95 values tabulated versus (N - 1) and (Nref  - 1).  If F is less than Fcrit95, then F passes the F-test at 95 % confidence.
Table 3 of §1065.602 - Critical F Values, Fcrit95, versus N - 1 and Nref - 1 at 95 % Confidence
                                     N - 1
                                       1
                                       2
                                       3
                                       4
                                       5
                                       6
                                       7
                                       8
                                       9
                                      10
                                      12
                                      15
                                      20
                                      24
                                      30
                                      40
                                      60
                                      120
                                     1000+
                                   Nref - 1

                                       1
                                     161.4
                                     199.5
                                     215.7
                                     224.5
                                     230.1
                                     233.9
                                     236.7
                                     238.8
                                     240.5
                                     241.8
                                     243.9
                                     245.9
                                     248.0
                                     249.0
                                     250.1
                                     251.1
                                     252.2
                                     253.2
                                     254.3
                                       2
                                     18.51
                                     19.00
                                     19.16
                                     19.24
                                     19.29
                                     19.33
                                     19.35
                                     19.37
                                     19.38
                                     19.39
                                     19.41
                                     19.42
                                     19.44
                                     19.45
                                     19.46
                                     19.47
                                     19.47
                                     19.48
                                     19.49
                                       3
                                     10.12
                                     9.552
                                     9.277
                                     9.117
                                     9.014
                                     8.941
                                     8.887
                                     8.845
                                     8.812
                                     8.786
                                     8.745
                                     8.703
                                     8.660
                                     8.639
                                     8.617
                                     8.594
                                     8.572
                                     8.549
                                     8.526
                                       4
                                     7.709
                                     6.944
                                     6.591
                                     6.388
                                     6.256
                                     6.163
                                     6.094
                                     6.041
                                     5.999
                                     5.964
                                     5.912
                                     5.858
                                     5.803
                                     5.774
                                     5.746
                                     5.717
                                     5.688
                                     5.658
                                     5.628
                                       5
                                     6.608
                                     5.786
                                     5.410
                                     5.192
                                     5.050
                                     4.950
                                     4.876
                                     4.818
                                     4.773
                                     4.735
                                     4.678
                                     4.619
                                     4.558
                                     4.527
                                     4.496
                                     4.464
                                     4.431
                                     4.399
                                     4.365
                                       6
                                     5.987
                                     5.143
                                     4.757
                                     4.534
                                     4.387
                                     4.284
                                     4.207
                                     4.147
                                     4.099
                                     4.060
                                     4.000
                                     3.938
                                     3.874
                                     3.842
                                     3.808
                                     3.774
                                     3.740
                                     3.705
                                     3.669
                                       7
                                     5.591
                                     4.737
                                     4.347
                                     4.120
                                     3.972
                                     3.866
                                     3.787
                                     3.726
                                     3.677
                                     3.637
                                     3.575
                                     3.511
                                     3.445
                                     3.411
                                     3.376
                                     3.340
                                     3.304
                                     3.267
                                     3.230
                                       8
                                     5.318
                                     4.459
                                     4.066
                                     3.838
                                     3.688
                                     3.581
                                     3.501
                                     3.438
                                     3.388
                                     3.347
                                     3.284
                                     3.218
                                     3.150
                                     3.115
                                     3.079
                                     3.043
                                     3.005
                                     2.967
                                     2.928
                                       9
                                     5.117
                                     4.257
                                     3.863
                                     3.633
                                     3.482
                                     3.374
                                     3.293
                                     3.230
                                     3.179
                                     3.137
                                     3.073
                                     3.006
                                     2.937
                                     2.901
                                     2.864
                                     2.826
                                     2.787
                                     2.748
                                     2.707
                                      10
                                     4.965
                                     4.103
                                     3.708
                                     3.478
                                     3.326
                                     3.217
                                     3.136
                                     3.072
                                     3.020
                                     2.978
                                     2.913
                                     2.845
                                     2.774
                                     2.737
                                     2.700
                                     2.661
                                     2.621
                                     2.580
                                     2.538
                                      11
                                     4.844
                                     3.982
                                     3.587
                                     3.357
                                     3.204
                                     3.095
                                     3.012
                                     2.948
                                     2.896
                                     2.854
                                     2.788
                                     2.719
                                     2.646
                                     2.609
                                     2.571
                                     2.531
                                     2.490
                                     2.448
                                     2.405
                                      12
                                     4.747
                                     3.885
                                     3.490
                                     3.259
                                     3.106
                                     2.996
                                     2.913
                                     2.849
                                     2.796
                                     2.753
                                     2.687
                                     2.617
                                     2.544
                                     2.506
                                     2.466
                                     2.426
                                     2.384
                                     2.341
                                     2.296
                                      13
                                     4.667
                                     3.806
                                     3.411
                                     3.179
                                     3.025
                                     2.915
                                     2.832
                                     2.767
                                     2.714
                                     2.671
                                     2.604
                                     2.533
                                     2.459
                                     2.420
                                     2.380
                                     2.339
                                     2.297
                                     2.252
                                     2.206
                                      14
                                     4.600
                                     3.739
                                     3.344
                                     3.112
                                     2.958
                                     2.848
                                     2.764
                                     2.699
                                     2.646
                                     2.602
                                     2.534
                                     2.463
                                     2.388
                                     2.349
                                     2.308
                                     2.266
                                     2.223
                                     2.178
                                     2.131
                                      15
                                     4.543
                                     3.682
                                     3.287
                                     3.056
                                     2.901
                                     2.791
                                     2.707
                                     2.641
                                     2.588
                                     2.544
                                     2.475
                                     2.403
                                     2.328
                                     2.288
                                     2.247
                                     2.204
                                     2.160
                                     2.114
                                     2.066
                                      16
                                     4.494
                                     3.634
                                     3.239
                                     3.007
                                     2.852
                                     2.741
                                     2.657
                                     2.591
                                     2.538
                                     2.494
                                     2.425
                                     2.352
                                     2.276
                                     2.235
                                     2.194
                                     2.151
                                     2.106
                                     2.059
                                     2.010
                                      17
                                     4.451
                                     3.592
                                     3.197
                                     2.965
                                     2.810
                                     2.699
                                     2.614
                                     2.548
                                     2.494
                                     2.450
                                     2.381
                                     2.308
                                     2.230
                                     2.190
                                     2.148
                                     2.104
                                     2.058
                                     2.011
                                     1.960
                                      18
                                     4.414
                                     3.555
                                     3.160
                                     2.928
                                     2.773
                                     2.661
                                     2.577
                                     2.510
                                     2.456
                                     2.412
                                     2.342
                                     2.269
                                     2.191
                                     2.150
                                     2.107
                                     2.063
                                     2.017
                                     1.968
                                     1.917
                                      19
                                     4.381
                                     3.522
                                     3.127
                                     2.895
                                     2.740
                                     2.628
                                     2.544
                                     2.477
                                     2.423
                                     2.378
                                     2.308
                                     2.234
                                     2.156
                                     2.114
                                     2.071
                                     2.026
                                     1.980
                                     1.930
                                     1.878
                                      20
                                     4.351
                                     3.493
                                     3.098
                                     2.866
                                     2.711
                                     2.599
                                     2.514
                                     2.447
                                     2.393
                                     2.348
                                     2.278
                                     2.203
                                     2.124
                                     2.083
                                     2.039
                                     1.994
                                     1.946
                                     1.896
                                     1.843
                                      21
                                     4.325
                                     3.467
                                     3.073
                                     2.840
                                     2.685
                                     2.573
                                     2.488
                                     2.421
                                     2.366
                                     2.321
                                     2.250
                                     2.176
                                     2.096
                                     2.054
                                     2.010
                                     1.965
                                     1.917
                                     1.866
                                     1.812
                                      22
                                     4.301
                                     3.443
                                     3.049
                                     2.817
                                     2.661
                                     2.549
                                     2.464
                                     2.397
                                     2.342
                                     2.297
                                     2.226
                                     2.151
                                     2.071
                                     2.028
                                     1.984
                                     1.938
                                     1.889
                                     1.838
                                     1.783
                                      23
                                     4.279
                                     3.422
                                     3.028
                                     2.796
                                     2.640
                                     2.528
                                     2.442
                                     2.375
                                     2.320
                                     2.275
                                     2.204
                                     2.128
                                     2.048
                                     2.005
                                     1.961
                                     1.914
                                     1.865
                                     1.813
                                     1.757
                                      24
                                     4.260
                                     3.403
                                     3.009
                                     2.776
                                     2.621
                                     2.508
                                     2.423
                                     2.355
                                     2.300
                                     2.255
                                     2.183
                                     2.108
                                     2.027
                                     1.984
                                     1.939
                                     1.892
                                     1.842
                                     1.790
                                     1.733
                                      25
                                     4.242
                                     3.385
                                     2.991
                                     2.759
                                     2.603
                                     2.490
                                     2.405
                                     2.337
                                     2.282
                                     2.237
                                     2.165
                                     2.089
                                     2.008
                                     1.964
                                     1.919
                                     1.872
                                     1.822
                                     1.768
                                     1.711
                                      26
                                     4.225
                                     3.369
                                     2.975
                                     2.743
                                     2.587
                                     2.474
                                     2.388
                                     2.321
                                     2.266
                                     2.220
                                     2.148
                                     2.072
                                     1.990
                                     1.946
                                     1.901
                                     1.853
                                     1.803
                                     1.749
                                     1.691
                                      27
                                     4.210
                                     3.354
                                     2.960
                                     2.728
                                     2.572
                                     2.459
                                     2.373
                                     2.305
                                     2.250
                                     2.204
                                     2.132
                                     2.056
                                     1.974
                                     1.930
                                     1.884
                                     1.836
                                     1.785
                                     1.731
                                     1.672
                                      28
                                     4.196
                                     3.340
                                     2.947
                                     2.714
                                     2.558
                                     2.445
                                     2.359
                                     2.291
                                     2.236
                                     2.190
                                     2.118
                                     2.041
                                     1.959
                                     1.915
                                     1.869
                                     1.820
                                     1.769
                                     1.714
                                     1.654
                                      29
                                     4.183
                                     3.328
                                     2.934
                                     2.701
                                     2.545
                                     2.432
                                     2.346
                                     2.278
                                     2.223
                                     2.177
                                     2.105
                                     2.028
                                     1.945
                                     1.901
                                     1.854
                                     1.806
                                     1.754
                                     1.698
                                     1.638
                                      30
                                     4.171
                                     3.316
                                     2.922
                                     2.690
                                     2.534
                                     2.421
                                     2.334
                                     2.266
                                     2.211
                                     2.165
                                     2.092
                                     2.015
                                     1.932
                                     1.887
                                     1.841
                                     1.792
                                     1.740
                                     1.684
                                     1.622
                                      40
                                     4.085
                                     3.232
                                     2.839
                                     2.606
                                     2.450
                                     2.336
                                     2.249
                                     2.180
                                     2.124
                                     2.077
                                     2.004
                                     1.925
                                     1.839
                                     1.793
                                     1.744
                                     1.693
                                     1.637
                                     1.577
                                     1.509
                                      60
                                     4.001
                                     3.150
                                     2.758
                                     2.525
                                     2.368
                                     2.254
                                     2.167
                                     2.097
                                     2.040
                                     1.993
                                     1.917
                                     1.836
                                     1.748
                                     1.700
                                     1.649
                                     1.594
                                     1.534
                                     1.467
                                     1.389
                                      120
                                     3.920
                                     3.072
                                     2.680
                                     2.447
                                     2.290
                                     2.175
                                     2.087
                                     2.016
                                     1.959
                                     1.911
                                     1.834
                                     1.751
                                     1.659
                                     1.608
                                     1.554
                                     1.495
                                     1.429
                                     1.352
                                     1.254
                                     1000+
                                     3.842
                                     2.996
                                     2.605
                                     2.372
                                     2.214
                                     2.099
                                     2.010
                                     1.938
                                     1.880
                                     1.831
                                     1.752
                                     1.666
                                     1.571
                                     1.517
                                     1.459
                                     1.394
                                     1.318
                                     1.221
                                     1.000

(h) Slope.  Calculate a least-squares regression slope, a1y, using one of the following two methods:
(1) If the intercept floats, i.e., is not forced through zero:

      Eq. 1065.602-9
Example:
N = 6000
y1 = 2045.8
= 1050.1
yref1 = 2045.0
= 1055.3

a1y = 1.0110
(2) If the intercept is forced through zero, such as for verifying proportional sampling:

      Eq. 1065.602-10
Example:
N = 6000
y1 = 2045.8
yref1 = 2045.0

a1y = 1.0110
(i) Intercept.  For a floating intercept, calculate a least-squares regression intercept, a0y, as follows:

      Eq. 1065.602-11
Example:
= 1050.1
a1y = 1.0110
 = 1055.3
a0y = 1050.1  -  (1.0110 · 1055.3)
a0y =  - 16.8083
(j) Standard error of the estimate.  Calculate a standard error of the estimate, SEE, using one of the following two methods:
(1) For a floating intercept:

      Eq. 1065.602-12
Example:
N = 6000
y1 = 2045.8
a0y =  - 16.8083
a1y = 1.0110
yref1 = 2045.0

SEEy = 5.348
(2) If the intercept is forced through zero, such as for verifying proportional sampling:

      Eq. 1065.602-13
Example:
N = 6000
y1 = 2045.8
a1y = 1.0110
yref1 = 2045.0

SEEy = 5.347
(k) Coefficient of determination.  Calculate a coefficient of determination, , as follows:

      Eq. 1065.602-14
Example:
N = 6000
y1 = 2045.8
a0y =  - 16.8083
a1y = 1.0110
yref1 =  2045.0
= 1480.5

 = 0.9859
(l) Flow-weighted mean concentration.  In some sections of this part, you may need to calculate a flow-weighted mean concentration to determine the applicability of certain provisions.  A flow-weighted mean is the mean of a quantity after it is weighted proportional to a corresponding flow rate.  For example, if a gas concentration is measured continuously from the raw exhaust of an engine, its flow-weighted mean concentration is the sum of the products of each recorded concentration times its respective exhaust molar flow rate, divided by the sum of the recorded flow rate values.  As another example, the bag concentration from a CVS system is the same as the flow-weighted mean concentration because the CVS system itself flow-weights the bag concentration.  You might already expect a certain flow-weighted mean concentration of an emission at its standard based on previous testing with similar engines or testing with similar equipment and instruments.  If you need to estimate your expected flow-weighted mean concentration of an emission at its standard, we recommend using the following examples as a guide for how to estimate the flow-weighted mean concentration expected at the standard.  Note that these examples are not exact and that they contain assumptions that are not always valid.  Use good engineering judgment to determine if you can use similar assumptions.
(1) To estimate the flow-weighted mean raw exhaust NOx concentration from a turbocharged heavy-duty compression-ignition engine at a NOx standard of 2.5 g/(kW·hr), you may do the following:
(i) Based on your engine design, approximate a map of maximum torque versus speed and use it with the applicable normalized duty cycle in the standard-setting part to generate a reference duty cycle as described in §1065.610.  Calculate the total reference work, Wref, as described in §1065.650.  Divide the reference work by the duty cycle's time interval, Δtdutycycle, to determine mean reference power, .
(ii) Based on your engine design, estimate maximum power, Pmax, the design speed at maximum power, fnmax, the design maximum intake manifold boost pressure, pinmax, and temperature, Tinmax.  Also, estimate a mean fraction of power that is lost due to friction and pumping, .  Use this information along with the engine displacement volume, Vdisp, an approximate volumetric efficiency, ηV, and the number of engine strokes per power stroke (two-stroke or four-stroke), Nstroke, to estimate the maximum raw exhaust molar flow rate, .
(iii) Use your estimated values as described in the following example calculation:

      Eq. 1065.602-15

      Eq. 1065.602-16
Example:
eNOx = 2.5 g/(kW∙hr)
Wref = 11.883 kW∙hr
MNOx = 46.0055 g/mol = 46.0055∙10[-6] g/μmol
Δtdutycycle = 20 min = 1200 s
= 35.65 kW
= 15 %
Pmax = 125 kW
pmax = 300 kPa = 300000 Pa
Vdisp = 3.0 l = 0.0030 m[3]/r
fnmax = 2800 r/min = 46.67 r/s
Nstroke = 4
ηV = 0.9
R = 8.314472 J/(mol∙K)
Tmax = 348.15 K

= 6.53 mol/s

= 189.4 umol/mol
(2) To estimate the flow-weighted mean NMHC concentration in a CVS from a naturally aspirated nonroad spark-ignition engine at an NMHC standard of 0.5 g/(kW∙hr), you may do the following:
(i) Based on your engine design, approximate a map of maximum torque versus speed and use it with the applicable normalized duty cycle in the standard-setting part to generate a reference duty cycle as described in §1065.610.  Calculate the total reference work, Wref, as described in §1065.650.
(ii) Multiply your CVS total molar flow rate by the time interval of the duty cycle, Δtdutycycle.  The result is the total diluted exhaust flow of the ndexh.
(iii) Use your estimated values as described in the following example calculation:

      Eq. 1065.602-17
Example:
eNMHC = 1.5 g/(kW∙hr)
Wref = 5.389 kW∙hr
MNMHC = 13.875389 g/mol = 13.875389∙10[-6] g/μmol
= 6.021 mol/s
Δtdutycycle= 30 min = 1800 s

= 53.8 umol/mol

349. Amend §1065.610 by revising paragraphs (a)(1)(iv), (a)(2) introductory text, and (d)(3) introductory text to read as follows:
§1065.610  Duty cycle generation.
*	*	*	*	*
(a)	*	*	*
(1)	*	*	*
(iv) Transform the map into a normalized power-versus-speed map by dividing power terms by Pmax and dividing speed terms by fnPmax.  Use the following equation to calculate a quantity representing the sum of squares from the normalized map:

      Eq. 1065.610-1
Where:
i = an indexing variable that represents one recorded value of an engine map.
fnnormi = an engine speed normalized by dividing it by fnPmax.
Pnormi = an engine power normalized by dividing it by Pmax.

*	*	*	*	*
(2) For engines with a high-speed governor that will be subject to a reference duty cycle that specifies normalized speeds greater than 100 %, calculate an alternate maximum test speed, fntest,alt, as specified in this paragraph (a)(2).  If fntest,alt is less than the measured maximum test speed, fntest, determined in paragraph (a)(1) of this section, replace fntest with fntest,alt.  In this case, fntest,alt becomes the "maximum test speed" for that engine for all duty cycles.  Note that §1065.510 allows you to apply an optional declared maximum test speed to the final measured maximum test speed determined as an outcome of the comparison between fntest, and fntest,alt in this paragraph (a)(2).  Determine fntest,alt as follows:
*	*	*	*	*
(d)	*	*	*
(3) Required deviations.  We require the following deviations for variable-speed engines intended primarily for propulsion of a vehicle with an automatic transmission where that engine is subject to a transient duty cycle with idle operation.  These deviations are intended to produce a more representative transient duty cycle for these applications.  For steady-state duty cycles or transient duty cycles with no idle operation, these requirements do not apply.  Idle points for steady-state duty cycles of such engines are to be run at conditions simulating neutral or park on the transmission.  You may develop different procedures for adjusting CITT as a function of speed, consistent with good engineering judgment.
*	*	*	*	*

350. Amend §1065.640 by revising paragraph (a), (b)(3), (d)(1), and (d)(3) to read as follows:
§1065.640  Flow meter calibration calculations.
*	*	*	*	*
(a) Reference meter conversions.  The calibration equations in this section use molar flow rate, , as a reference quantity.  If your reference meter outputs a flow rate in a different quantity, such as standard volume rate, , actual volume rate, , or mass rate,, convert your reference meter output to a molar flow rate using the following equations, noting that while values for volume rate, mass rate, pressure, temperature, and molar mass may change during an emission test, you should ensure that they are as constant as practical for each individual set point during a flow meter calibration:

      Eq. 1065.640-1
Where:
= reference molar flow rate.
= reference volume flow rate corrected to a standard pressure and a standard temperature.
= reference volume flow rate at the actual pressure and temperature of the flow rate.
= reference mass flow.
pstd = standard pressure.
pact = actual pressure of the flow rate.
Tstd = standard temperature.
Tact = actual temperature of the flow rate.
R = molar gas constant.
Mmix = molar mass of the flow rate.
Example 1:
= 1000.00 ft[3]/min = 0.471948 m[3]/s
pstd = 29.9213 in Hg @ 32 °F = 101.325 kPa = 101325 Pa = 101325 kg/(m∙s[2])
Tstd = 68.0 °F = 293.15 K
R = 8.314472 J/(mol∙K) = 8.314472 (m[2]∙kg)/(s[2]∙mol∙K)

= 19.619 mol/s
Example 2:
= 17.2683 kg/min = 287.805 g/s
Mmix = 28.7805 g/mol

= 10.0000 mol/s
(b)	*	*
(3) Perform a least-squares regression of Vrev, versus Ks, by calculating slope, a1, and intercept, a0, as described for a floating intercept in §1065.602.
*	*	*	*	*
(d)	*	*	*
(1) Calculate the Reynolds number, Re[#], for each reference molar flow rate, , using the throat diameter of the venturi, dt.  Because the dynamic viscosity, u, is needed to compute Re[#], you may use your own fluid viscosity model to determine u for your calibration gas (usually air), using good engineering judgment.  Alternatively, you may use the Sutherland three-coefficient viscosity model to approximate u, as shown in the following sample calculation for Re[#]:

      Eq. 1065.640-10
Where, using the Sutherland three-coefficient viscosity model as captured in Table 4 of this section:

      Eq. 1065.640-11
Where:
u0 = Sutherland reference viscosity.
T0 = Sutherland reference temperature.
S = Sutherland constant.
Table 4 of §1065.640 -
Sutherland Three-Coefficient Viscosity Model Parameters
                                    Gas[a]

                                      u0
                                      T0
                                       S
                    Temperature range within +-2 % error[b]
                               Pressure limit[b]

                                  kg/(m∙s)
                                       K
                                       K
                                       K
                                      kPa
                                      Air
                                1.716∙10[-5]
                                      273
                                      111
                                  170 to 1900
                                   <= 1800
                                      CO2
                                1.370∙10[-5]
                                      273
                                      222
                                  190 to 1700
                                   <= 3600
                                      H2O
                                 1.12∙10[-5]
                                      350
                                     1064
                                  360 to 1500
                                  <= 10000
                                      O2
                                1.919∙10[-5]
                                      273
                                      139
                                  190 to 2000
                                   <= 2500
                                      N2
                                1.663∙10[-5]
                                      273
                                      107
                                  100 to 1500
                                   <= 1600
[a]Use tabulated parameters only for the pure gases, as listed.  Do not combine parameters in calculations to calculate viscosities of gas mixtures.
[b]The model results are valid only for ambient conditions in the specified ranges.

Example:
u0 = 1.716∙10[-5] kg/(m∙s)
T0 = 273 K
S = 111 K

u = 1.838∙10[-5] kg/(m∙s)
Mmix = 28.7805 g/mol = 0.0287805 kg/mol
= 57.625 mol/s
dt = 152.4 mm = 0.1524 m
Tin = 298.15 K

Re[#] = 7.538∙10[5]
*	*	*	*	*
(3) Perform a least-squares regression analysis to determine the best-fit coefficients for the equation and calculate SEE as described in §1065.602.  When using Eq. 1065.640-12, treat Cd as y and the radical term as yref and use Eq. 1065.602-12 to calculate SEE.  When using another mathematical expression, use the same approach to substitute that expression into the numerator of Eq. 1065.602-12 and replace the 2 in the denominator with the number of coefficients in the mathematical expression.
*	*	*	*	*

351. Amend §1065.642 by revising paragraphs (b) and (c)(1) to read as follows:
§1065.642  PDP, SSV, and CFV molar flow rate calculations.
*	*	*	*	*
(b) SSV molar flow rate.  Calculate SSV molar flow rate, , as follows:

      Eq. 1065.642-3
Where:
Cd = discharge coefficient, as determined based on the Cd versus Re[#] equation in §1065.640(d)(2).
Cf = flow coefficient, as determined in §1065.640(c)(3)(ii).
At = venturi throat cross-sectional area.
pin = static absolute pressure at the venturi inlet.
Z = compressibility factor.
Mmix = molar mass of gas mixture.
R = molar gas constant.
Tin = absolute temperature at the venturi inlet.
Example:
At = 0.01824 m[2]
pin = 99.132 kPa = 99132 Pa = 99132 kg/(m∙s[2])
Z = 1
Mmix = 28.7805 g/mol = 0.0287805 kg/mol
R = 8.314472 J/(mol·K) = 8.314472 (m[2]∙kg)/(s[2]∙mol∙K)
Tin = 298.15 K
Re[#] = 7.232·10[5]
γ = 1.399
β = 0.8
Δp = 2.312 kPa

Using Eq. 1065.640-7,
rssv = 0.997

Using Eq. 1065.640-6,
Cf = 0.274

Using Eq. 1065.640-5,
Cd = 0.990

= 58.173 mol/s
(c)	*	*	*
(1) To calculate  through one venturi or one combination of venturis, use its respective mean Cd and other constants you determined according to §1065.640 and calculate  as follows:

      Eq. 1065.642-4
Where:
Cf = flow coefficient, as determined in §1065.640(c)(3).

Example:
Cd = 0.985
Cf = 0.7219
At = 0.00456 m[2]
pin = 98.836 kPa = 98836 Pa = 98836 kg/(m∙s[2])
Z = 1
Mmix = 28.7805 g/mol = 0.0287805 kg/mol
R = 8.314472 J/(mol·K) = 8.314472 (m[2]∙kg)/(s[2]∙mol∙K)
Tin = 378.15 K

= 33.690 mol/s
*	*	*	*	*

352. Add §1065.643 to read as follows:
§1065.643  Carbon balance error verification calculations.
This section describes how to calculate quantities used in the carbon balance error verification described in §1065.543.  Paragraphs (a) through (c) of this section describe how to calculate the mass of carbon for a test interval from carbon-carrying fluid streams, intake air into the system, and exhaust emissions, respectively.  Paragraph (d) of this section describes how to use these carbon masses to calculate four different quantities for evaluating carbon balance error.  Use rectangular or trapezoidal integration methods to calculate masses and amounts over a test interval from continuously measured or calculated mass and molar flow rates.
(a) Fuel and other fluids.  Determine the mass of fuel, DEF, and other carbon-carrying fluid streams, other than intake air, flowing into the system, mfluidj, for each test interval.  Note that §1065.543 allows you to omit all flows other than fuel.  You may determine the mass of DEF based on ECM signals for DEF flow rate.  You may determine fuel mass during field testing based on ECM signals for fuel flow rate. Calculate the mass of carbon from the combined carbon-carrying fluid streams flowing into the system as follows:

      Eq. 1065.643-1
Where:
j = an indexing variable that represents one carbon-carrying fluid stream.
N = total number of carbon-carrying fluid streams into the system over the test interval.
wC = carbon mass fraction of the carbon-carrying fluid stream as determined in §1065.655(d).
mfluid = the mass of the carbon-carrying fluid stream determined over the test interval.
Example:
N = 2
wCfuel = 0.869
wCDEF = 0.065
mfuel = 1119.6 g
mDEF = 36.8 g

(b) Intake air. Calculate the mass of carbon in the intake air, mCair, for each test interval using one of the methods in this paragraph (b).  The methods are listed in order of preference.  Use the first method where all the inputs are available for your test configuration.  For methods that calculate mCair based on the amount of CO2 per mole of intake air, we recommend measuring intake air concentration, but you may calculate xCO2int using Eq. 1065.655-10 and letting xCO2intdry = 375 umol/mol.
(1) Calculate mCair, using the following equation if you measure intake air flow:

      Eq. 1065.643-2
Where:
MC = molar mass of carbon.
nint = measured amount of intake air over the test interval.
xCO2int = amount of intake air CO2 per mole of intake air.
Example:
MC = 12.0107 g/mol
nint = 62862 mol
xCO2int = 369 umol/mol = 0.000369 mol/mol

(2) Calculate mCair, using the following equation if you measure or calculate raw exhaust flow and you calculate chemical balance terms:

      Eq. 1065.643-3
Where:
MC = molar mass of carbon.
nexh = calculated or measured amount of raw exhaust over the test interval.
xH2Oexh = amount of H2O in exhaust per mole of exhaust.
xCO2int = amount of intake air CO2 per mole of intake air.
xdil/exhdry = amount of excess air per mole of dry exhaust.  Note that excess air and intake air have the same composition, so xCO2dil = xCO2int and xH2Odil = xH2Oint for the chemical balance calculation for raw exhaust.
xint/exhdry = amount of intake air required to produce actual combustion products per mole of dry exhaust.
Example:
MC = 12.0107 g/mol
nexh = 62862 mol
xH2Oexh = 0.034 mol/mol
xCO2int = 369 umol/mol = 0.000369 mol/mol
xdil/exhdry = 0.570 mol/mol
xint/exhdry = 0.465 mol/mol

(3) Calculate mCair, using the following equation if you measure raw exhaust flow:

      Eq. 1065.643-4
Where:
MC = molar mass of carbon.
nexh = measured amount of raw exhaust over the test interval.
xCO2int = amount of intake air CO2 per mole of intake air.
Example:
MC = 12.0107 g/mol
nexh = 62862 mol
xCO2int = 369 umol/mol = 0.000369 mol/mol

(4) Calculate mCair, using the following equation if you measure diluted exhaust flow and dilution air flow:

      Eq. 1065.643-5
Where:
MC = molar mass of carbon.
ndexh = measured amount of diluted exhaust over the test interval as determined in §1065.642.
ndil = measured amount of dilution air over the test interval as determined in §1065.667(b).
xCO2int = amount of intake air CO2 per mole of intake air.
Example:
MC = 12.0107 g/mol
ndexh = 942930 mol
ndil = 880068 mol
xCO2int = 369 umol/mol = 0.000369 mol/mol

(5) Determined mCair based on ECM signals for intake air flow as described in paragraph (b)(1) of this section.
(6) If you measure diluted exhaust, determine mCair as described in paragraph (b)(4) of this section using a calculated amount of dilution air over the test interval as determined in §1065.667(d) instead of the measured amount of dilution air.
(c) Exhaust emissions. Calculate the mass of carbon in exhaust emissions, mCexh, for each test interval as follows:

      Eq. 1065.643-6
Where:
MC = molar mass of carbon.
mCO2 = mass of CO2 over the test interval as determined in §1065.650(c).
MCO2 = molar mass of carbon dioxide.
mCO = mass of CO over the test interval as determined in §1065.650(c).
MCO = molar mass of carbon monoxide.
mTHC = mass of THC over the test interval as determined in §1065.650(c).
MTHC = effective C1 molar mass of total hydrocarbon as defined in §1065.1005(f)(2).
Example:
MC = 12.0107 g/mol
mCO2 = 4567 g
MCO2 = 44.0095 g/mol
mCO = 0.803 g
MCO = 28.0101 g/mol
mTHC = 0.537 g
MTHC = 13.875389 g/mol

(d) Carbon balance error quantities.  Calculate carbon balance error quantities as follows:
(1) Calculate carbon mass absolute error, ϵaC, for a test interval as follows:

      Eq. 1065.643-7
Where:
mCexh = mass of carbon in exhaust emissions over the test interval as determined in paragraph (d) of this section.
mCfluid = mass of carbon in all the carbon-carrying fluid streams flowing into the system over the test interval as determined in paragraph (a) of this section.
mCair = mass of carbon in the intake air flowing into the system over the test interval as determined in paragraph (b) of this section.
Example:
mCexh = 1247.2 g
mCfluid = 975.3 g
mCair = 278.6 g

(2) Calculate carbon mass rate absolute error, ϵaCrate, for a test interval as follows:

Eq. 1065.643-8
Where:
t = duration of the test interval.
Example:
ϵaC =  - 6.7 g
t = 1202.2 s = 0.3339 hr

(3) Calculate carbon mass relative error, ϵrC, for a test interval as follows:

      Eq. 1065.643-9
 Example:
ϵaC =  - 6.7 g
mCfliud = 975.3 g
mCair = 278.6 g

(4) Calculate composite carbon mass relative error, ϵrCcomp, for a duty cycle with multiple test intervals as follows:
(i) Calculate ϵrCcomp using the following equation:

            Eq. 1065.643-10
Where:
i = an indexing variable that represents one test interval.
N = number of test intervals.
WF = weighting factor for the test interval as defined in the standard-setting part.
mCexh = mass of carbon in exhaust emissions over the test interval as determined in paragraph (c) of this section.
mCfluid = mass of carbon in all the carbon-carrying fluid streams that flowed into the system over the test interval as determined in paragraph (a) of this section.
mCair = mass of carbon in the intake air that flowed into the system over the test interval as determined in paragraph (b) of this section.
t = duration of the test interval.  For duty cycles with multiple test intervals of a prescribed duration, such as cold-start and hot-start transient cycles, set t = 1 for all test intervals.  For discrete-mode steady-state duty cycles with multiple test intervals of varying duration, set t equal to the actual duration of each test interval.
(ii) The following example illustrates calculation of ϵrCcomp, for cold-start and hot-start transient cycles:
N = 2
WF1 = 1/7
WF2 = 6/7
mCexh1 = 1255.3 g
mCexh2 = 1247.2 g
mCfluid1 = 977.8 g
mCfluid2 = 975.3 g
mCair1 = 280.2 g
mCair2 = 278.6 g

(iii) The following example illustrates calculation of ϵrCcomp for multiple test intervals with varying duration, such as discrete-mode steady-state duty cycles:

N = 2
WF1 = 0.85
WF2 = 0.15
mCexh1 = 2.873 g
mCexh2 = 0.125 g
mCfluid1 = 2.864 g
mCfluid2 = 0.095 g
mCair1 = 0.023 g
mCair2 = 0.024 g
t1 = 123 s
t2 = 306 s

353. Amend §1065.650 by revising paragraphs (b)(3) introductory text, (c)(1), (c)(2)(i) introductory text, (c)(3), (d) introductory text, (d)(7), (f)(2) introductory text, and (g) to read as follows:
§1065.650  Emission calculations.
*	*	*	*	*
(b)	*	*	*
(3) For field testing, you may calculate the ratio of total mass to total work, where these individual values are determined as described in paragraph (f) of this section.  You may also use this approach for laboratory testing, consistent with good engineering judgment.  Good engineering judgment dictates that this method not be used if there are any work flow paths described in §1065.210 that cross the system boundary, other than the primary output shaft (crankshaft).  This is a special case in which you use a signal linearly proportional to raw exhaust molar flow rate to determine a value proportional to total emissions. You then use the same linearly proportional signal to determine total work using a chemical balance of fuel, DEF, intake air, and exhaust as described in §1065.655, plus information about your engine's brake-specific fuel consumption.  Under this method, flow meters need not meet accuracy specifications, but they must meet the applicable linearity and repeatability specifications in subpart D or subpart J of this part.  The result is a brake-specific emission value calculated as follows:
*	*	*	*	*
(c)	*	*	*
(1) Concentration corrections. Perform the following sequence of preliminary calculations on recorded concentrations:
(i) Use good engineering judgment to time-align flow and concentration data to match transformation time, t50, to within +-1 s.
(ii) Correct all gaseous emission analyzer concentration readings, including continuous readings, sample bag readings, and dilution air background readings, for drift as described in §1065.672.  Note that you must omit this step where brake-specific emissions are calculated without the drift correction for performing the drift validation according to §1065.550(b).  When applying the initial THC and CH4 contamination readings according to §1065.520(f), use the same values for both sets of calculations.  You may also use as-measured values in the initial set of calculations and corrected values in the drift-corrected set of calculations as described in §1065.520(f)(7).
(iii) Correct all THC and CH4 concentrations for initial contamination as described in §1065.660(a), including continuous readings, sample bags readings, and dilution air background readings.