( c) Unless we approve otherwise in advance, you may not use equipment, instruments, or tools to identify bad engine components unless you specify they should be used for scheduled maintenance on production engines. In 165 this case, if they are not generally available, you must also make them available at dealerships and other service outlets.

( d) You may adjust, repair, disassemble, or replace the test engine only with our approval. We may approve these steps if all the following occur:

( 1) Something clearly malfunctions   such as persistent misfire, engine stall, overheating, fluid leaks, or loss of oil pressure   and needs maintenance or repair.

( 2) You provide us an opportunity to verify the extent of the malfunction before you do the maintenance.

( e) If we determine that a part failure, system malfunction, or associated repairs have made the engine's emission controls unrepresentative of production engines, you may no longer use it as a test 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 a test engine.

§ 1065.415 Durability demonstration. If the standard setting part requires durability testing, you must accumulate service in a way that represents how you expect the engine to operate in use. You may accumulate service hours using an accelerated schedule, such as through continuous operation.

( a) Maintenance. The following limits apply to the maintenance that we allow you to do on a test engine:

( 1) You may perform scheduled maintenance that you recommend to operators, but only if it is consistent with the standard setting part's restrictions.

( 2) You may perform additional maintenance only as specified in § 1065.410( b).

( b) Emission measurements. Perform emission tests following the provisions of this part and the standard setting part. Perform emission tests to determine deterioration factors consistent with good engineering judgment. Evenly space any tests between the first and last test points throughout the durability period, unless we approve otherwise.

Subpart F   Running an Emission Test in the Laboratory § 1065.501 Overview. ( a) Use the procedures detailed in this subpart to measure engine emissions in a laboratory by performing the following tasks:

( 1) Map your engine by recording specified torque and speed data.

( 2) Use your engine map to transform normalized duty cycles into reference duty cycles for your engine.

( 3) Prepare your engine, equipment, and measurement instruments for an emission test.

( 4) Perform pre test procedures to verify proper operation of certain equipment and analyzers.

( 5) Record pre test data.

( 6) Start or restart the engine and sampling systems.

( 7) Sample emissions throughout the duty cycle.

( 8) Record post test data.

( 9) Perform post test procedures to verify proper operation of certain equipment and analyzers.

( b) The general test consists of a duty cycle made of one or more of the following segments ( check the standard setting part for specific duty cycles):

( 1) Either a cold start transient cycle where you measure emissions, or a warm up cycle where you do not measure emissions. Transient testing consists of a sequence of target values for speed and torque that change continuously throughout the duty cycle.

( 2) A hot start transient test. Some duty cycles may omit engine starting from the " hot start" cycle. 166 ( 3) A steady state test with a warmed up engine. Steady state tests may involve discrete mode discrete mode testing or ramped modal testing. Discrete mode testing consists of a series of discrete test modes with engine operation stabilized at fixed speeds and torques, with separate emission measurements for each mode. Ramped modal testing consists of a continuous time trace that includes a series of stable operating modes connected by defined transitions, with a single emission measurement for the whole cycle.

( c) Other subparts in this part identify how to select and prepare an engine for testing ( subpart E), perform the required engine service accumulation ( subpart E), and calculate emission results ( subpart G).

( d) Subpart J of this part describes how to perform field testing.

§ 1065.510 Engine mapping. ( a) Scope and frequency. An engine map is a data set that consists of a series of paired values for engine speed and maximum brake torque. Map your engine while it is connected to a dynamometer. 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. Map or re map an engine before a test if any of the following apply:

( 1) You have not performed an initial engine map.

( 2) The barometric pressure near the engine's air inlet is not within 5 % of the barometric pressure recorded at the time of the last engine map.

( 3) The engine or emission control system has undergone changes that might affect maximum torque performance.

( 4) You capture an incomplete map on your first attempt or you do not complete a map within the specified time tolerance. You may repeat mapping as necessary to capture a complete map within the specified time.

( 5) You may update an engine map at any time by repeating the engine mapping procedure.

( b) Mapping variable speed engines. Map variable speed engines as follows:

( 1) Record the barometric pressure.

( 2) Warm up the engine by operating it at any speed and at ( 75 ± 10) % of maximum mapped power until either the engine coolant's temperature or block absolute temperature is within ± 2 % of its mean value for at least 2 min or until the engine thermostat controls engine temperature.

( 3) Operate the engine at its warm, no load idle speed.

( 4) Set operator demand to maximum and control engine speed at ( 95 ± 1) % of its warm, no load idle speed for at least 15 s. For engines with reference duty cycles whose lowest speed is greater than warm, no load idle speed, you may start the map at ( 95 ± 1) % of the lowest reference speed.

( 5) Perform one of the following:

( i) For any naturally aspirated engine or for any engine subject only to steady state duty cycles, you may map it at discrete speeds by selecting at least 20 evenly spaced setpoints between warm, no load idle and the highest speed above maximum mapped power at which ( 50 to 75) % of maximum power occurs. At each setpoint, stabilize speed and allow torque to stabilize. Record the average speed and torque at each setpoint. We recommend that you stabilize an engine for at least 15 s at each setpoint and record the average feedback speed and torque of the last ( 4 to 6) s. Use linear interpolation to determine intermediate speed and torque values.

( ii) For any variable speed engine, you may map it by using a continuous sweep of speed by continuing to record the mean feedback speed and torque at 1 Hz or more frequently and increasing speed at a constant rate such that it takes ( 4 to 6) min to sweep from 95 % of warm, no load idle to the highest speed above maximum power at which ( 50 to 75) % of maximum power occurs. Stop recording after you complete the sweep. From the series of mean speed and maximum torque values, use linear interpolation to determine intermediate values. Use this series of speed and torque values to generate the power map as described in paragraph ( e) of this section. 167 ( c) Negative torque mapping. If your engine is subject to a reference duty cycle that specifies negative torque values, generate a motoring map by any of the following procedures:

( 1) Multiply the positive torques from your map by  40 %. Use linear interpolation to determine intermediate values.

( 2) Map the amount of negative torque required to motor the engine by repeating paragraph ( c) of this section without fuel, or with minimum operator demand if operating without fuel would damage the engine.

( 3) Determine the amount of negative torque required to motor the engine at the following two points: at warm, no load idle and at the highest speed above maximum power at which ( 50 to 75) % of maximum power occurs. Operate the engine without fuel, or with minimum operator demand if operating without fuel would damage the engine. Use linear interpolation to determine intermediate values.

( d) Mapping constant speed engines. For constant speed engines, generate a map as follows:

( 1) Record the barometric pressure.

( 2) Warm up the engine by operating it at any speed and at ( 75 ± 10) % of maximum mapped power until either the engine coolant's temperature or block absolute temperature is within ± 2 % of its mean value for at least 2 min or until the engine thermostat controls engine temperature.

( 3) You may operate the engine with a production constant speed governor or simulate a constant speed governor by controlling engine speed with an operator demand control system described in § 1065.110. The installed governor may be an isochronous or a speed droop governor.

( 4) With the governor or simulated governor controlling speed via operator demand, operate the engine at noload governed speed ( at high speed, not low idle) for at least 15 s.

( 5) Record mean feedback speed and torque at 1 Hz or more frequently and use the dynamometer to increase torque at a constant rate, such that it takes ( 2 to 4) min to sweep from no load governed speed to the lowest speed below maximum mapped power at which the engine develops ( 85 95) % of maximum mapped power. Stop recording after you complete the sweep. Use this series of speed and torque values to generate the power map as described in paragraph ( e) of this section.

( e) Power mapping. For all engines, create a power versus speed map by transforming torque and speed values to corresponding power values. Use the mean values from the recorded map data. Do not use any interpolated values. Multiply each torque by its corresponding speed and apply the appropriate conversion factors to arrive at units of power ( kW).

( f) Test speed and test torque. Transform your duty cycles using maximum test speed for variable speed engines and maximum test torque for constant speed engines. You may declare maximum test speed before mapping as long as it is within ( 97.5 to 102.5) % of its mapped value. You may declare maximum test torque before mapping as long as it is within ( 95 to 100) % of its mapped value. Otherwise, you must use the measured value for transforming duty cycles.

( g) Other mapping procedures. You may use other mapping procedures if you believe the procedures specified in this section are unsafe or unrepresentative for your engine. Any alternate techniques must satisfy the intent of the specified mapping procedures, which is to determine the maximum available torque at all engine speeds that occur during a duty cycle. Report any deviations from this section's mapping procedures.

§ 1065.512 Duty cycle generation. ( a) The standard setting part defines applicable duty cycles in a normalized format. A normalized duty cycle consists of a sequence of paired values for speed and torque or for speed and power.

( b) Transform normalized values of speed, torque, and power using the following conventions:

( 1) Engine speed for variable speed engines. For variable speed engines, normalized speed may be expressed as a percentage between idle speed and maximum test speed, fntest, or speed may be expressed by referring to a defined speed by name, such as " warm, no load 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. 168 Note that the cycle validation criteria in § 1065.514 allow an engine to govern itself at its in use idle speed. This allowance permits you to test engines with enhanced idle devices.

( 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 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 representing curb idle transmission torque ( CITT).

( 3) Engine torque speed for constant speed engines. For constant speed engines, normalized torque is expressed as a percentage of maximum test torque, Ttest. Section 1065.610 describes how to transform normalized torques into a sequence of reference torques, Tref. Section 1065.610 also describes under what conditions you may command Tref greater than 0 N · m when a normalized duty cycle specifies a 0 % torque command.

( 4) Engine power. For all engines, normalized power is expressed as a percentage of mapped power at maximum test speed, fntest. Section 1065.610 describes how to transform these normalized values into a sequence of reference powers Pref. You may convert these reference powers to reference speeds and torques for operator demand and dynamometer control.

( c) Commands for variable speed engines. Command reference speeds and torques sequentially to perform a duty cycle. Update commands and record reference and feedback values at a frequency of at least 5 Hz. Use smooth transitions between reference values.

( d) Commands for constant speed engines. Use dynamometer controls to command reference torques sequentially for performing a duty cycle. Operate the engine with a production constant speed governor or simulate a constantspeed governor by controlling engine speed with an operator demand control system described in § 1065.110. Update commands and record reference and feedback values at a frequency of at least 5 Hz. Use smooth transitions between reference values.

( d) Practice cycles. You may perform practice duty cycles with the test engine to optimize operator demand and dynamometer controls to meet the cycle validation criteria specified in § 1065.514.

§ 1065.514 Cycle validation criteria. This section describes how to determine if a test engine's feedback speeds and torques adequately matched the reference values in a duty cycle. For any data required in this section, use the reference and feedback values that you recorded during a test interval.

( a) Testing performed by EPA. Our tests must meet the specifications of paragraph ( h) of this section, unless we determine that failing to meet the specifications is related to engine performance rather than shortcomings of the dynamometer or other laboratory equipment.

( b) Testing performed by manufacturers. Emission tests that meet the specifications of paragraph ( h) of this section satisfy the standard setting part's requirements for duty cycles. You may ask to use a dynamometer or other laboratory equipment that cannot meet those specifications. We will approve your request as long as using the alternate equipment does not affect your ability to show compliance with the applicable emission standards.

( c) Time alignment. Because time lag between feedback values and the reference values may bias cycle validation results, you may advance or delay the entire sequence of feedback engine speed and torque pairs to synchronize them with the reference sequence.

( d) Power. Before omitting any points under paragraph ( e) of this section, calculate feedback power, Pi and reference power, Prefi, and calculate total work, W and reference work, Wref, as described in § 1065.650.

( e) Omitting points. You may omit certain points from duty cycle regression statistics, which are also summarized in Table 1 of this section, as follows:

( 1) When operator demand is at its minimum you may omit the following points:

( i) Power and torque, if the reference torque is negative ( i. e., engine motoring). 169 ( ii) Power and speed, if the reference speed corresponds to an idle command ( 0 %), the reference torque corresponds to a minimum command ( 0 %), and the absolute value of the feedback torque is less than the corresponding reference torque plus 2 % of the maximum mapped torque.

( iii) Two out of three of power, torque, and speed if either feedback speed or feedback torque is greater its reference command. You may not omit a point from regression statistics if both feedback speed and torque are greater than their reference commands.

( 2) When operator demand is at its maximum, you may omit two out of three of power, torque, and speed if either feedback speed or feedback torque is less than its reference command. You may not omit a point from regression statistics if both feedback speed and torque are less than their reference commands.

Table 1 of § 1065.514   Summary of point omission criteria from duty cycle regression statistics When operator demand is at its... you may omit... if...

minimum power and torque Tref < 0 minimum Power and speed fnref = idle ( 0 %) and Tref = minimum ( 0 %) and

T

< Tref + 2 % · Tmax mapped minimum 2 out of 3 of power, torque, and speed fn > fnref or T > Tref but not if fn > fnref and T > Tref maximum 2 out of 3 of power, torque, and speed fn < fnref or T < Tref but not if fn < fnef and T < Tref ( g) Use the remaining points to calculate regression statistics described in § 1065.602, as follows:

( 1) Slopes for feedback speed, a1fn, feedback torque, a1T, and feedback power a1P.

( 2) Intercepts for feedback speed, a0fn, feedback torque, a0T, and feedback power a0P.

( 3) Standard estimates of error for feedback speed, SEfn, feedback torque, SET, and feedback power SEP.

( 4) Coefficients of determination for feedback speed, r2 fn, feedback torque, r2T, and feedback power r2 P.

( h) Cycle statistics. Unless the standard setting part specifies otherwise, use the following criteria to validate a duty cycle:

( 1) For variable speed engines only, feedback total work must be at or below 105 % of reference total work.

( 2) For variable speed engines only, apply all the statistical criteria in Table 2 of this section.

( 3) For constant speed engines, apply the statistical criteria only for torque in the Table 2 of this section.

Table 2 of § 1065.514   Default statistical criteria for validating duty cycles Parameter Speed Torque Power Slope, a1 0.950 to 1.030 0.830 to 1.030 0.830 to1.030 Absolute value of intercept, | a0| ± 10 % of warm idle ± 2 % of maximum mapped torque ± 2 % of maximum mapped power Standard error of estimate, SE ± 5 % of maximum test speed ± 10 % of maximum mapped torque ± 10 % of maximum mapped power Coefficient of determination, r2 0.970 0.850 0.910 170 § 1065.520 Pre test verification procedures and pre test data collection. ( a) If your engine must comply with a PM standard, follow the procedures for PM sample preconditioning and tare weighing in § 1065.590.

( b) Unless the standard setting part specifies different values, verify that ambient conditions before the test are within the following tolerances:

( 1) Ambient temperature of ( 20 to 30)  C.

( 2) Barometric pressure of ( 80.000 to 103.325) kPa and within ± 5 % of the value recorded at the time of the last engine map.

( 3) Dilution air as specified in § 1065.140( b).

( c) You may test engines at any humidity.

( d) You may perform a final calibration of the speed, torque, and proportional flow control systems, which may include performing practice duty cycles.

( e) You may perform the following recommended procedure to precondition sampling systems:

( 1) Start the engine and use good engineering judgment to bring it to 100 % torque above its peak torque speed.

( 2) Operate any dilution systems at their expected flow rates. Prevent aqueous condensation in the dilution systems.

( 3) Operate any PM sampling systems at their expected flow rates.

( 4) Sample PM for at least 10 min using any sample media. You may change sample media during preconditioning. You may discard preconditioning samples without weighing them.

( 5) You may purge any gaseous sampling systems during preconditioning.

( 6) You may conduct calibrations or performance checks on any idle equipment or analyzers during preconditioning.

( 7) Proceed with the test sequence described in § 1065.530( a)( 1).

( f) HC contamination check. After the last practice or preconditioning cycle before an emission test, check for contamination in the HC sampling system as follows:

( 1) Select the HC analyzer range for measuring the flow weighted average concentration expected at the HC standard.

( 2) Zero the HC analyzer using zero air introduced at the analyzer port.

( 3) Span the HC analyzer using span gas introduced at the analyzer port. Span on a carbon number basis of one ( 1), C1. For example, if you use a C3H8 span gas of concentration 200 µ mol/ mol, span the FID to respond with a value of 600 µ mol/ mol.

( 4) Overflow zero air at the HC probe or into a fitting between the HC probe and the transfer line.

( 5) Measure the HC concentration in the sampling system, as follows:

( i) For continuous sampling, record the mean HC concentration as overflow zero air flows.

( ii) For batch sampling, fill the sample medium and record its mean HC concentration.

( 6) Record this value as the initial HC concentration, xHCinit, and use it to correct measured values as described in § 1065.660.

( 7) If xHCinit exceeds the greatest of the following values, determine the source of the contamination and take corrective action, such as purging the system or replacing contaminated portions:

( i) 2 % of the flow weighted average concentration expected at the standard or measured during testing, whichever is greater.

( ii) 2 mmol/ mol. 171 ( 8) If corrective action does not resolve the deficiency, you may request to use the contaminated system as an alternate procedure under § 1065.10.

§ 1065.525 Engine starting, restarting, and shutdown. ( a) Start the engine using one of the following methods:

( 1) Start the engine as recommended in the owners manual using a production starter motor and a fully charged battery or a power supply.

( 2) Use the dynamometer to start the engine. To do this, motor the engine within ± 25 % of its typical in use cranking speed. Accelerate the engine to cranking speed within ± 25 % of the time it would take with an inuse engine. Stop cranking within 1 s of starting the engine.

( b) If the engine does not start after 15 s of cranking, stop cranking and determine why the engine failed to start, unless the owners manual or the service repair manual describes the longer cranking time as normal.

( c) Respond to engine stalling with the following steps:

( 1) If the engine stalls during warm up before emission sampling begins, restart the engine and continue warm up.

( 2) If the engine stalls during preconditioning before emission sampling begins, restart the engine and restart the preconditioning sequence.

( 3) If the engine stalls at any other time after emission sampling begins, the test is void.

( d) Shut down the engine according to the manufacturer's specifications.

§ 1065.530 Emission test sequence. ( a) Time the start of testing as follows:

( 1) Perform one of the following if you precondition sampling systems as described in § 1065.520( d):

( i) For cold start duty cycles, shut down the engine. Unless the standard setting part specifies otherwise, you may use forced cooling to stabilize the temperature of the engine and any aftertreatment systems. You may start a cold start duty cycle when the temperatures of an engine's lubricant, coolant, and aftertreatment systems are between ( 20 and 30)  C.

( ii) For hot start emission measurements, shut down the engine. Start a hot start duty cycle within 20 min of engine shutdown.

( iii) For testing that involves hot stabilized emission measurements, such as steady state testing, you may continue to operate the engine at fntest and 100 % torque if that is the first operating point. Otherwise, operate the engine at warm, no load idle or the first operating point of the duty cycle. In any case, start the duty cycle within 10 min after you complete the preconditioning procedure.

( 2) For all other testing, perform one of the following:

( i) For cold start duty cycles, start the engine and the duty cycle when the temperatures of an engine's lubricant, coolant, and aftertreatment systems are between ( 20 and 30)  C. Unless the standard setting part specifies otherwise, you may use forced cooling to stabilize the temperature of the engine and any aftertreatment system.

( ii) For hot start emission measurements, first operate the engine at any speed above peak torque speed and at ( 65 to 85) % of maximum mapped power until either the engine coolant temperature or block absolute temperature is within 2 % of its mean value for at least 2 min or until the engine thermostat controls engine temperature. Shut down the engine. Start the duty cycle within 20 min of engine shutdown.

( iii) For testing that involves hot stabilized emission measurements, bring the engine either to warm, no load idle or the first operating point of the duty cycle. Start the test within 10 min of achieving temperature stability. You may determine temperature stability either as the point at which the engine 172 coolant temperature or the block absolute temperature is within 2 % of its mean value for at least 2 min, or the point at which the engine thermostat controls engine temperature.

( b) Take the following steps before emission sampling begins:

( 1) For batch sampling, connect clean storage media, such as evacuated bags or tare weighed filters.

( 2) Start all measurement instruments according to the instrument manufacturer's instructions.

( 2) Start dilution systems, sample pumps, cooling fans, and the data collection system.

( 3) Preheat any heat exchangers in the sampling system.

( 4) Allow heated components such as sample lines, filters, and pumps to stabilize at operating temperature.

( 5) Perform vacuum side leak checks as specified in § 1065.345.

( 6) Using bypass, adjust the sample flow rates to desired levels.

( 7) Zero any integrating devices.

( 9) Zero and span all constituent analyzers using NIST traceable gases that meet the specifications of § 1065.750. Span flame ionization detector analyzers on a carbon number basis of one ( 1), C1. For example, if you use a C3H8 span gas of concentration 200 µ mol/ mol, span the FID to respond with a value of 600 µ mol/ mol.

( 10) If you choose to correct for dilution air background concentrations of engine exhaust constituents, start measuring and recording background constituent concentrations.

( c) Start testing as follows:

( 1) If an engine is already running and warmed up, and starting is not part of the duty cycle, simultaneously start running the duty cycle, sampling exhaust gases, recording data, and integrating measured values.

( 2) If engine starting is part of the duty cycle, initiate data logging, sampling of exhaust gases, and integrating measured values before attempting to start the engine. Initiate the duty cycle when the engine starts.

( d) Before the end of the test interval, continue to operate all sampling and dilution systems to allow the sampling system's response time to elapse. Then stop all sampling and recording, including the recording of background samples. Finally, stop any integrating devices and indicate the end of the duty cycle on the data collection medium.

( e) Shut down the engine if you have completed testing or if it is part of the duty cycle.

( f) If testing involves another duty cycle after a soak period with the engine off, start a timer when the engine shuts down, and repeat the steps in paragraphs ( b) through ( e) of this section as needed.

( g) Take the following steps after emission sampling is complete:

( 1) Place any used PM samples into covered or sealed containers and return them to the PM stabilization environment. Follow the PM sample post conditioning and total weighing procedures in § 1065.595.

( 2) As soon as practical after the duty cycle is complete, analyze any gaseous batch samples, including background samples.

( 3) After quantifying exhaust gases, check drift as follows:

( i) Record the mean analyzer value after stabilizing a zero gas to the analyzer. Stabilization may include time to purge the analyzer of any sample gas, plus any additional time to account for analyzer response.

( ii) Record the mean analyzer value after stabilizing the span gas to the analyzer. Stabilization may include time to purge the analyzer of any sample gas, plus any additional time to account for analyzer response.

( iii) Use these data to validate and correct for drift as described in § 1065.657.

( h) Determine if the test meets the validation criteria in § 1065.514. 173 § 1065.545 Validation of proportional flow control for batch sampling. ( a) For any proportional batch sample such as a bag sample or PM filter sample, demonstrate that proportional sampling was maintained using one of the following:

( 1) Record the ratio of the sample flow rate to total flow rate at 1 Hz or more frequently. Demonstrate that the ratio was constant within ± 5.0 % of the mean or target ratio over each test interval.

( 2) Record the sample flow rate and the total flow rate at 1 Hz or more frequently. Demonstrate that each flow rate was constant within ± 2.5 % of its mean or target ratio over each test interval.

( 3) For critical flow venturis, record venturi inlet conditions at 1 Hz or more frequently. Demonstrate that the density at the venturi inlet was constant within ± 2.5 % of the mean or target value over each test interval or, for a CVS critical flow venturi, that the absolute temperature at the venturi inlet was constant within ± 4 % of the mean or target value over each test interval.

( 4) For positive displacement pumps, record pump inlet conditions at 1 Hz or more frequently. Demonstrate that the density at the pump inlet was constant within ± 2.5 % of the mean or target value over each test interval or, for a CVS pump, that the absolute temperature at the pump inlet was constant within ± 2 % of the mean or target value over each test interval.

( 5) Using good engineering judgment, demonstrate using an engineering analysis that the proportional flow control system inherently ensures proportional sampling under all circumstances expected during testing. For example, you use CFVs for sample flow and total flow and their inlet pressures and temperatures are always the same as each others, and they always operate under critical flow conditions.

§ 1065.550 Constituent analyzer range validation, drift validation, and drift correction. ( a) Check the results of all analyzers that do not have auto ranging capability to determine if any results show that an analyzer operated above 100 % of its range. If an analyzer operated above 100 % of its range at any time during the test, perform the following steps:

( 1) For batch sampling, re analyze the sample using the nearest analyzer range that results in a maximum instrument response below 100 %. Report the result from the lowest range from which the analyzer operates below 100 % of its range for the entire test. Report all results.

( 2) For continuous sampling, repeat the entire test using the next higher analyzer range. If the analyzer again operates above 100 % of its range, repeat the test using the next higher range. Continue to repeat the test until the analyzer operates at less than 100 % of its range for the entire test. Report all results.

( b) Calculate and correct for drift as described in § 1065.657. Drift invalidates a test if the drift correction exceeds ± 4 % of the flow weighted average concentration expected at the standard or measured during a test interval, whichever is greater.

§ 1065.590 PM sample preconditioning and tare weighing. Before an emission test, take the following steps to prepare PM samples and equipment for PM measurements:

( a) Make sure the balance and PM stabilization environments meet the periodic performance checks in § 1065.390.

( b) Visually inspect unused sample media ( such as filters) for defects.

( c) To handle PM samples, use electrically grounded tweezers or a grounding strap, as described in § 1065.190.

( d) Place unused sample media in one or more containers that are open to the PM stabilization environment. If you are using filters, you may place them in the bottom half of a filter cassette.

( e) Stabilize sample media in the PM stabilization environment. Consider a sample medium stabilized as long as it has been in the PM stabilization environment for a minimum of 30 min, during which the PM stabilization environment has been within the specifications of § 1065.190.

( f) Weigh the sample media automatically or manually, as follows:

( 1) For automatic weighing, follow the automation system manufacturer's instructions to prepare samples for weighing. This may include placing the samples in a special container. 174 ( 2) For manual weighing, use good engineering judgment to determine if substitution weighing is necessary to show that an engine meets the applicable standard. You may follow the substitution weighing procedure in paragraph ( i) of this section, or you may develop your own procedure.

( g) Correct the measured weight for buoyancy as described in § 1065.690. These buoyancy corrected values are the tare masses of the PM samples.

( h) You may repeat measurements to determine mean masses. Use good engineering judgment to exclude outliers and calculate mean mass values.

( i) Substitution weighing involves measurement of a reference weight before and after each weighing of a PM sample. While substitution weighing requires more measurements, it corrects for a balance's zero drift and it relies on balance linearity only over a small range. This is advantageous when quantifying net PM masses that are less than 0.1 % of the sample medium's mass. However, it may not be advantageous when net PM masses exceed 1 % of the sample medium's mass. The following steps are an example of substitution weighing:

( 1) Use electrically grounded tweezers or a grounding strap, as described in § 1065.190.

( 2) Use a static neutralizer as described in § 1065.190 to minimize static electric charge on any object before it is placed on the balance pan.

( 3) Place on the balance pan a calibration weight that has a similar mass to that of the sample medium and meets the specifications for calibration weights in § 1065.790. If you use filters, this mass should be about ( 80 to 100) mg for typical 47 mm diameter filters.

( 4) Record the stable balance reading, then remove the calibration weight.

( 5) Weigh an unused sample, record the stable balance reading and record the balance environment's dewpoint, ambient temperature, and barometric pressure.

( 6) Reweigh the calibration weight and record the stable balance reading.

( 7) Calculate the arithmetic mean of the two calibration weight readings recorded immediately before and after weighing the unused sample. Subtract that mean value from the unused sample reading, then add the true mass of the calibration weight as stated on the calibration weight certificate. Record this result.

( 8) Repeat the steps in paragraphs ( i)( 1) through ( 7) of this section for additional unused sample media.

( j) If you use filters as sample media, load unused filters that have been tare weighed into filter cassettes and place the loaded cassettes in a covered or sealed container before taking them to the test cell for sampling. We recommend that you keep filter cassettes clean by periodically washing or wiping them with a compatible solvent. Depending upon your cassette material, ethanol might be an acceptable solvent.

§ 1065.595 PM sample post conditioning and total weighing. ( a) Make sure the balance and PM stabilization environments meet the periodic performance checks in § 1065.390.

( b) In the PM stabilization environment, remove PM samples from sealed containers. If you use filters, you may remove them from their cassettes before or after stabilization. When you remove a filter from a cassette, separate the top half of the cassette from the bottom half using a cassette separator designed for this purpose.

( c) To handle PM samples, use electrically grounded tweezers or a grounding strap, as described in § 1065.190.

( d) Visually inspect PM samples. If PM ever contacts the transport container, cassette assembly, filter separator tool, tweezers, static neutralizer, balance, or any other surface, void the measurements associated with that sample and clean the surface it contacted.

( e) To stabilize PM samples, place them in one or more containers that are open to the PM stabilization environment, which is described in § 1065.190. Consider a sample stabilized as long as it has been in the PMstabilization environment for a minimum of 30 min, during which the PM stabilization environment has been within the specifications of § 1065.190. Alternatively, for engines subject to PM standards above 0.05 g/ kW hr, you may consider a sample medium stabilized after 60 min.

( f) Repeat the procedures in § 1065.590( f) through ( h) to weigh used PM samples, but refer to a sample's post test mass after correcting for buoyancy as its total mass. 175 ( g) Subtract each buoyancy corrected tare mass from its respective buoyancy corrected total mass. The result is the net PM mass, mPM. Use mPM in emission calculations in § 1065.650.

Subpart G   Calculations and Data Requirements § 1065.601 Overview. ( a) This subpart describes how to use the signals recorded before, during, and after an emission test to calculate brake specific emissions of each regulated constituent.

( b) You may use data from multiple systems to calculate test results, consistent with good engineering judgment. We allow weighted averages where appropriate. You may discard statistical outliers, but you must report all results.

( c) Calculations for some calibrations and performance checks are in this subpart.

( d) Statistical values are defined in this subpart.

§ 1065.602 Statistics. ( a) 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, y 1 1 2 3 3 1 :

3 10.60 11.91 11.20 10.60 11.91 11.09 3 3 11.20 N i i N i i y y N Example N y y y y y y y =

= =

= = = = =

+ + = =

=

176 ( c) Standard deviation. Calculate a non biased ( e. g., N 1) sample standard deviation, , as follows:   ( )

( )

( )

( ) ( ) ( ) ( ) 2 1 1 2 3 3 2 2 2 2 1 1 :

3 10.60 11.91 11.09 11.20 11.2 10.60 11.2 11.91 11.2 11.09 11.2 3 1 2 0.6619 N i i y N i i y y y y N Example N y y y y y y       =

=   =

= = = = = =

    +   +   = =

=

( d) Root mean square. Calculate a root mean square, , as follows: y rms 177 2 1 1 2 3 2 2 2 1 :

3 10.60 11.91 11.09 10.60 11.91 11.09 3 11.21 N y i i N y y rms y N Example N y y y y rms rms = =

= = = = =

+ + =

=

( e) Accuracy. Calculate an accuracy, as follows, noting that the are arithmetic means, each determined by i y repeatedly measuring one sample of a single reference quantity, . ref y ( )

10 1 :

1800.0 10 1802.4 10 1800.0 1802.5 2.5 ref ref i i accuracy y y Example y N y y accuracy accuracy = =

=

=

= =

=

=

178 ( 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, , as follows:   2 2 2 2 9.399 10.583 11 7 :

1205.3 1123.8 9.399 10.583 11 7 1205.3 1123.8 16.63 ref y ref ref N N ref ref y ref y y t Example y y N N t t           = +

=

= =

=

=

=

  = +

= 179 ( ) ( )

( ) ( ) ( ) 2 2 2 2 2 2 2 2 2 2 2 2 2 1 1 2 9.399 10.583 11 7 9.399 11 10.583 7 11 1 7 1 :

9.399 11 10.583 7 11.76 ref y ref ref ref y ref N N N N N N ref ref y Example N N

 +     = +

=

=

=

=

+ = +

=

( 2) For a paired t test calculate the t statistic and its number of degrees of freedom, , as follows, noting that   the are the errors ( e. g., differences) between each pair of and :

i   refi y i y :

0.12580 16 0.04837 0.12580 16 0.04837 10.403 N t Example N t t               =

=   = =

    =

= 180 1 :

16 1 15 N Example N N       =

=

=

=

( 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.

Table 1 of § 1065.602: critical t values versus number of degrees of freedom, n.

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

( )

( )

( ) ( ) 2 2 2 1 2 1 2 2 :

10.583 1 9.399 1 10.583 9.399 1.268 ref y y ref N i i y N refi ref i ref ref F Example y y N y y N F F         =

= =

  = =

  = =

=

=

181 ( 1) For a 90 % confidence F test, use Table 2 of this section to compare F to the Fcrit90 values tabulated versus N minus one ( N 1) and Nref minus one ( Nref  1). If F is less than Fcrit90, then F passes the F test at 90 % confidence.

( 2) For a 95 % confidence F test, use Table 3 of this section to compare F to the Fcrit95 values tabulated versus N minus one ( N 1) and Nref minus one ( Nref  1). If F is less than Fcrit95, then F passes the F test at 95 % confidence.

Table 2 of § 1065.602: Critical F values versus N and Nref at 90 % confidence.

Table 3 of § 1065.602: Critical F values versus N and Nref at 95 % confidence.

( h) Slope. Calculate a least squares linear regression slope, , as follows: 1 a ( )

( )( ) ( )( ) ( ) ( ) 1 1 2 1 1 1 6000 6000 1 2 2 6000 1 ( )

( )

:

6000 2045.8 2045.0 1050.1 1055.3 2045.8 1050.1 2045.0 1055.3 ... 1050.1 1055.3 2045.8 1050.1 ... 1050.1 1.0110 N i refi ref i y N i i ref ref ref y y y y y y a y y Example N y y y y y y a y a =

=       =

= = =

= =

      + +       =   ++

=

( i) Intercept. Calculate a least squares linear regression intercept, , as follows: 1 a 182 ( )

( ) 0 1 1 0 0 :

1055.3 1.0110 1050.1 1055.3 1.0110 1050.1 6.5331 y ref y ref y y y a y a y Example y a y a a =

=

=

=

=

=

( j) Standard estimate of error. Calculate a standard estimate of error, SE, as follows:

[ ] 2 1 2 2 6000 6000 ( )

2 :

2045.0 6.5311 1.0110 2045.8 6000 2045.0 ( 6.5311) ( 1.0110 2045.8) ... ( 6.5311) ( 1.0110 )

6000 2 85.348 N ref i 0y 1y i i y ref 1 0y 1y 1 ref y y y a a y SE N example y a a y N y y SE SE =

     ×   =

=

=

=

= =

       × +       ×   =   =

( k) Coefficient of determination. Calculate a coefficient of determination, , as follows: 2 r 183 ( )

( ) ( ) ( )( ) 2 2 1 2 2 1 1 1 2 2 6000 6000 2 2 2 2 6000 6000 2 1 :

6000 2045.8 2045.0 6000 2045.8 2045.0 ... 1 6000 2045.8 ... 2045.8 ...

0.98590 N i refi i y N N i i i i ref 1 ref y y N y y r N y y example N y y y y r y y r =

= = ×   =

 ×               = = =

  ×   ++

 =     × + +   ++

 =

( k) Flow weighted average concentration. A flow weighted average means the average 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 average concentration is the sum of the products of each recorded concentration times its respective exhaust flow rate, divided by the number of recorded values. As another example, the bag concentration from a CVS system is the same as the flow weighted average concentration because the CVS system itself flow weights the bag concentration. You might already expect a certain flow weighted average 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 average concentration of an emission at its standard, we recommend using the following examples as a guide for how to estimate the flow weighted average concentration expected at a standard. Note that these examples are not exact and that they contain assumptions that are not always valid. Use good engineering judgement to determine if you can use similar assumptions.

( 1) To estimate the flow weighted average raw exhaust NOx concentration from a turbo charged 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 maximum torque versus speed map 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, to determine average reference power, . duty cycle t   ref P ( ii) Based on your engine design, estimate maximum power, Pmax, the design speed at maximum power,

fnmax, and the design maximum intake manifold boost pressure, pinmax and temperature Tinmax. Also estimate 184 an average fraction of power that is lost due to friction and pumping, . Use this information along frict P with the engine displacement volume, Vdisp, an approximate volumetric efficiency, , and the number of V   engine power strokes per cycle ( e. g., 2 stroke or 4 stroke) to estimate the maximum raw exhaust flow rate, . exhmax n

( iii) Use your estimated values as described in the following example calculation: 185 ( )

2 :

2.5 g/( kW hr)

11.883 kW hr 20 min 46.0055 g/ mol 35.65 kW std ref exp ref frict max exhmax duty cycle max max disp nmax V stroke exhmax max NOx ref duty cycle NOx ref max e W x P P P M n t P p V f N n R T Example e W t M P P   =

 +         =

= =

  =

=

=

=

   3 125 kW 15 %

0.9 300 kPa 3.0 l 2800 rev/ min 4 1/ rev 8.314472 J/( mol K)

348.15 K 1000 Pa/ kPa 1000 l/ m 60 s/ min 1000000 µ mol/ mol 2 300 3.0 2800 0.9 1000 4 8.314472 frict V max disp nmax stroke max p V t mol exhmax P p V f N R T C C C C n   =

= = =

= = = = =

= = =

=

 ( ) 6.53 mol/ s 348.15 1000 60 2.5 11.883 1000000 35.65 0.15 125 46.0055 6.53 20 60 125 189.4 µ mol/ mol exp exp x x =

=

 +       =          186 ( 2) To estimate the flow weighted average 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 maximum torque versus speed map 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 flow rate by the time interval of the duty cycle, . The result is the duty cycle t

total diluted exhaust flow of the ndexh.

( iii) Use your estimated values as described in the following example calculation:

:

1.5 g/( kW hr)

5.389 kW hr 13.875389 g/ mol 6.021 mol/ s 30 min 60 s/ min 1000000 µ mol/ mol 1.5 5.389 100 13.875389 6.021 30 60 std ref NMHC dexh duty cycle NMHC ref NMHC dexh duty cycle t mol NMHC e W x M n t Example e W M n t C C x =

= =

= =   =

= =

=

     0000 53.8 µ mol/ mol NMHC x =

§ 1065.605 Field test system overall performance check. ( a) This section contains equations and example calculations for statistics that are specified in § 1065.920 for fieldtesting systems. In this section we use the letter " e" to denote the brake specific emissions of a test interval, the superscript over bar "

" to denote an arithmetic mean, the subscript " lab" to denote a laboratory result, and the subscript " field" to denote a field testing result.

( b) Assume that the brake specific data in the following table was collected by performing the overall field test system check as described in § 1065.920.

Table 1 of 1065.605: Example of data set from a field test system overall check. 187 ( c) For example, calculate for the first test interval , , and as follows: 1 field e 1 lab e 1 / lab std e e

( ) 1 1 1 1 1 1 1 1 1 7 2.00 2.10 2.30 2.40 2.20 2.00 2.20 7 2.17 /

similarly,

1.90 2.00 2.20 2.30 2.10 1.90 2.10 7 2.07 /

/ /

2.50 N field i i field field field lab lab lab std field lab lab std lab std e e N N e e gkWhr e e gkWhr e e e e e e g = =

= + + + + + + =

=

+ + + + + + =

=

  =

=

( ) 1 1 /

/ 2.17 2.07 / 2.50 / 4.0% lab std lab std kW hr e e e e   =

  =

( d) For example, calculate for the second test interval , , as follows: 2 field UCL 2 lab UCL 2 UCL   188 2 2 2 2 2 2 2 2 2 see 1065.602( c) for .

For UCL, recalculate and after applying measurement allowance.

Example measurement allowance= 0.95 3.258 2 0.278 3.81 / field field e field e field field e field field field UCL e e UCL UCL g kW       = +

= +

=

2 2 2 2 2 2 2 similarly,

3.500 2 0.216 3.93 /

3.81 3.93 0.12 / lab lab field lab hr UCL UCL g kW hr UCL UCL UCL UCL UCL g kW hr = +

=

  =

  =     =

§ 1065.610 Test cycle generation. ( a) Maximum test speed, fntest and maximum test torque Ttest. For all engines, calculate test speed from the power versus speed map generated as per § 1065.510.

( 1) Based on the power versus speed map, determine the maximum power and the speed at which maximum power occurred. Divide each recorded power by the maximum power and divide each recorded speed by the speed at which maximum power occurred. The resulting data set is a normalized data set of power versus speed. Use this data set to determine test speed. Test speed is the speed at which the normalized data set returns a maximum value of the sum of the squares of normalized speed and normalized power.

( 2) For example: 189 ( )

( )( ) max max 2 2 @ 1 @

2 2 @ max :

2355 rev/ min 1.002, 0.978 1.004, 0.977 1.006, 0.974 1.002 0.978 1.960 N ntest n P nnormi nnnormi normi i n P nnorm1 norm1 nnorm2 norm2 nnorm3 norm3 2 2 nnorm1 norm1 nnorm f f f f P Example f f P f P f P f + P f =

 = +     =

= = = = = =

= + =

( )( ) ( )( )

[ ] 2 2 2 2 1.004 0.977 1.963 1.006 0.974 1.961 max 1.963@ 2 2355 1.004 2364 rev/ min 2 2 2 norm2 2 2 nnorm3 norm3 ntest + P f + P i f = + =

= + =

= = = =

( 3) For variable speed engines, use this measured test speed   or your declared test speed as described in § 1065.510   to transform normalized speeds to reference speeds as described in paragraph ( b) of this section.

( 4) For constant speed engines, use the torque corresponding to this measured test speed as measured test torque   or your declared test torque as described in § 1065.510   to transform normalized torques to reference torques as described in paragraph ( c) of this section.

( b) Speed. Transform normalized speed values to reference values as follows:

( 1) % speed. If your normalized duty cycle specifies % speed values, use your declared warm no load idle speed and your test speed to transform the duty cycle, as follows: 190 ( )

( ) %

:

% 85%

2364 rev/ min 650 rev/ min 85% 2364 650 650 2107 rev/ min nref ntest nidle nidle ntest nidle nref nref f speed f f f Example speed f f f f =   +

= = =

=   +

=

( 2) A, B, and C speeds. If your normalized duty cycle specifies speed values as A, B, or C values, use your power versus speed curve to determine the lowest speed below maximum power at which 50 % of maximum power occurs. Denote this value as nlo. Also determine the highest speed above maximum power at which 70 % of maximum power occurs. Denote this value as nhi. Use nhi and nlo to calculate reference values for A, B, or C speeds as follows:

( ) ( ) ( )

( ) ( ) ( ) 0.25 0.50 0.75 :

1005 rev/ min 2385 rev/ min 0.25 2385 1005 1005 0.50 2385 1005 1005 0.75 2385 1005 1005 1350 rev/ nrefA hi lo lo nrefB hi lo lo nrefC hi lo lo lo lo nrefA nrefB nrefC nrefA f n n n f n n n f n n n Example n n f f f f =   +

=   +

=   +

= =

=   +

=   +

=   +

=

min 1695 rev/ min 2040 rev/ min nrefB nrefC f f =

= 191 ( 3) Intermediate speed. If your normalized duty cycle specifies a speed as " intermediate speed", use your torque versus speed curve to determine the speed at which maximum torque occurs.

( i) Determine the speed at which peak torque occurs. This is peak torque speed.

( ii) If peak torque speed is between ( 60 to 75) % of test speed, then your reference intermediate speed is peak torque speed.

( iii) If peak torque speed is less than 60 % of test speed, then your reference intermediate speed is 60 % of test speed.

( iv) If peak torque speed is greater than 75 % of test speed, then your reference intermediate speed is 75 % of test speed.

( c) Torque. Transform normalized torque values to reference values using your maximum torque versus speed map. For variable speed engines you must first transform normalized speed values into reference speed values. For constant speed engines, you need only your test torque value.

( 1) % torque for variable speed engines. For a given speed point, multiply the corresponding % torque by the maximum torque at that speed, according to your map. Linearly interpolate mapped torque values to determine torque between mapped speeds. The result is the reference torque for that speed point.

( 2) % torque for constant speed engines. Multiply a % torque value by your test torque. The result is the reference torque for that point.

( 3) Permissible deviations for any engine. If your engine does not operate in use below a certain torque under certain conditions, you may use a declared minimum torque as the reference value instead of the value calculated in paragraph ( c)( 1) or ( 2) of this section. For example, if your engine is connected to an automatic transmission, it may have a minimum torque called curb idle transmission torque ( CITT). In this case, at idle conditions ( i. e., 0% speed, 0 % torque), you may use CITT as a reference value instead of 0 N

m.

( d) Power. Transform normalized power values to reference speed and torque values using your maximum power versus speed map. For variable speed engines you must first transform normalized speed values into reference speed values. For constant speed engines, you need only your maximum power value.

( 1) % power for variable speed engines. For a given speed point, multiply the corresponding % power by the maximum power of your entire map. The result is the reference power for that speed point. You may calculate a corresponding reference torque for that point and command that reference torque instead of a reference power.

( 2) % torque for constant speed engines. Multiply a % power value by the maximum power of your entire map. The result is the reference power for that point. You may calculate a corresponding reference torque for that point and command that reference torque instead of a reference power.

( 3) Permissible deviations for any engine. If your engine does not operate in use below a certain power under certain conditions, you may use a declared minimum power as the reference value instead of the value calculated in paragraph ( d)( 1) or ( 2) of this section. For example, if your engine is directly connected to a propeller, it may have a minimum power called idle power. In this case, at idle conditions ( i. e., 0% speed, 0 % torque), you may use a corresponding idle torque as a reference torque instead of 0 N

m.

§ 1065.630 1980 international gravity formula. Calculate the acceleration of Earth's gravity at your latitude, as follows: 192 2 4 6 8 2 4 6 9.7803267715 ( 1+ 5.2790414E 03 sin( ) 2.32718E 05 sin( ) 1.262E 07 sin( ) 7E 10 sin( ) )

:

45 9.7803267715 ( 1+ 5.2790414E 03 sin( 45) 2.32718E 05 sin( 45) 1.262E 07 sin( 45) 7E 10 sin( 45 g g a Example a           = × × + × + × + × =

= × × + × + × + ×

8 2 ) )

9.8178291229 m/ s g a =

§ 1065.640 PDP and venturi ( SSV and CFV) calibration calculations.

( a) Reference meter conversions. The following calibration equations use molar flow rate, as a reference ref n

quantity. If your reference meter outputs a flow rate in a different quantity such as standard volume rate, 193 actual volume rate, or mass rate, , convert your reference meter output to molar flow rate stdref V

actref V

ref m

using the following: 3 o o o o 3 3 :

1000.00 ft / min 29.9213 in Hg @ 32 F 68.0 F 8.314472 J/( mol K)

3386.38 Pa/ in Hg @ 32 F ( + 459.67)/ 1.8 K/ F 35.314662 ft / m stdref std actref act ref ref std act mix stdref std std p T V V P V P m n T R T R M Examples V P T R C C T C = = =

=

=

= =

=

=

=

 [ ] 60 s/ min 1000.00 29.9213 3386.38 19.619 mol/ s ( 68.0+ 459.67)/ 1.8 8.314472 35.314662 60 17.2683 kg/ min 28.7805 g/ mol 1000 g/ kg 17.2683 1000 10.000 mol/ s 28.7805 60 t ref ref mix m ref C n m M C n =

= =

=

= =

= =

 ( b) PDP calibration calculations. For each restrictor position, calculate the following values, from the mean values determined in § 1065.340, as follows:

( 1) PDP volume pumped per revolution, Vrev m3/ rev: 194 ( ) 3 3 :

25.096 mol/ s 8.314472 J/ mol K 299.5 K 98.290 kPa 1205.1 rev/ min 60 s/ min 1000 J/ m / kPa 60 25.096 8.314472 299.5 1000 98.290 1205.1 0.03166 m / rev ref in rev in PDP ref in in PDP t p rev rev n RT V P f Example n R T P f C C V V =

=

=

=

=

= =

=

=

=

     ( 2) PDP slip correction factor, Ks s/ rev:

1 :

1205.1 rev/ min 100.103 kPa 98.290 kPa 60 s/ min 60 1 100.103 98.290 1205.1 100.103 0.006700 s/ rev out in s out PDP PDP out in t s s P P K P f Example f P P C K K   =

=

=

= =

  =

=

195 ( 3) Perform a least squares linear regression of PDP volume pumped per revolution, Vrev versus PDP slip correction factor, Ks, by calculating slope, a1 and intercept a0 as described in § 1065.602.

( 4) Repeat the procedure in paragraphs ( a)( 1) through ( 3) of this section for every speed that you run your PDP.

( 5) Use the slopes and intercepts to calculate flow rate during emission testing as described in § 1065.642.

( c) Venturi governing equations and allowable assumptions. Because a subsonic venturi ( SSV) and a critical flow venturi ( CFV) both operate similarly, their governing equations are the same, except for the equation describing their pressure ratio r ( i. e., rSSV versus rCFV). The following symbols are used for the following quantities in subsequent calculations:

venturi throat cross sectional area discharge coefficient flow coefficient mass conversion factor pressure conversion factor venturi throat diameter molar mass of gas mixture molar t d f m p t mix A C C C C d M n = = =

= =

= = =

flow rate venturi inlet absolute static pressure pressure ratio venturi inlet absolute temperature compressibility factor ratio of venturi throat to inlet diameters differential static in in p r T Z p   = = = = =   = pressure; venturi inlet minus venturi throat ratio of specific heats of gas mixture   =

( ) 1 2 1 2 1 2 4 4 2 1 1 1 1 1 2 2 t in d f mix in f SSV in CFV CFV A p n C C Z M RT r C r p r p r r

  =

          	   =

   =

  +   + =

196 ( 1) You may iterate to solve for rCFV and subsequently calculate Cf for a CFV, CfCFV, or you may determine CfCFV from Table 1 of § 1065.640, based on your b and g.

Table 1 of § 1065.640: CfCFV versus b and g ( 2) Permissible assumptions. You may make several simplifying assumptions of the governing equations.

( i) For emission testing over the full ranges of raw exhaust, diluted exhaust and dilution air, you may assume that the gas mixture behaves as an ideal gas: Z= 1.

( ii) For the full range of raw exhaust you may assume a constant ratio of specific heats of g= 1.385.

( iii) For the full range of diluted exhaust and air ( e. g., calibration air or dilution air), you may assume a constant ratio of specific heats of g= 1.399.

( iv) For the full range of diluted exhaust and air, you may assume the molar mass of the mixture is a function only of the amount of water in the dilution air or calibration air, xH2O, determined as described in § 1065.645, as follows:

( 1 )

:

28.96559 g/ mol 0.0169 mol/ mol 18.01528 g/ mol 28.96559 ( 1 0.0169) 18.01528 0.0169 28.7805 g/ mol mix air H2O H2O H2O air H2O H2O mix mix M M x M x Example M x M M M =   +

= = =

=   + =

( v) For the full range of diluted exhaust and air, you may assume a constant molar mass of the mixture, Mmix such that the assumed molar mass differs from the actual molar mass by no more than ± 1 % for all calibration and all testing. This might occur if you sufficiently control the amount of water in calibration air and in dilution air, and this might occur if you remove sufficient water from both calibration air and dilution air. Table 2 of this section gives examples of permissible emission testing dilution air dewpoints versus calibration air dewpoints.

Table 2 of § 1065.640: Permissible ranges of dilution air dewpoint versus calibration dewpoint where a constant Mmix may be assumed ( 3) Calibration equation for SSV and CFV. For each data point collected in § 1065.340, solve for Cd. The following example illustrates the use of the governing equations for the SSV. Note that for the case of the CFV, the equation for Cd would be the same. However, for Cf you would use your values of b and g to 197 determine Cf iteratively as described in paragraph ( b)( 1) of this section, or you would look up a constant value of Cf for all calibration and testing in Table 1 of § 1065.640.

( ) 1 2 1 2 4 2 2 1 1 1 :

57.625 mol/ s 1 28.7805 g/ mol 8.314472 J/ mol K 298.15 K 0.01824 m 99.132 kPa = 1.399 = mix in d ref f t in f SSV in ref mix in t in Z M R T C n C A p r C r p r p Example n Z M R T A p

  =

          	   =

   =

=

= = = =

= =

( ) ( )( ) 1.399 1 1.399 2 1.399 1 2 4 0.8 2.312 kPa 1000 g/ kg 1000 Pa/ kPa 1 0.977 2 1.399 1 0.977 1.399 1 0.977 0.8 0.274 1 28.7805 8.314472 298.15 / 1000 57.625 0.274 0.01824 99.132 1000 m p SSV in SSV f f d p C C p r p r C C C

    = = =

  =

=

     =

 =

=

0.981 d C = 198 ( i) SSV calibration. For each data point collected in § 1065.340, also calculate Re# at the throat of the venturi. Because the dynamic viscosity, m. is needed to compute Re#, you may use your own fluid viscosity model to determine m, using good engineering judgment. Alternatively, you may use the Sutherland three coefficient viscosity model for air at moderate pressures and temperatures. An example of this is shown in the following example calculation for Re# :

3 2 0 0 0 5 0 0 5 4 Sutherland model:

1.7894 10 kg/( m s)

273.11 K 110.56 K :

28.7805 g/ mol 57.625 mol/ s 0.1524 m 298.15 K 1000 g/ kg 1.7894 10 mix ref #

in in mix ref t in m M n Re = d T T S T T S T S Example M n d T C   µ µ µ µ µ

 + =     +     = = =

= =

= = =

=

 3 2 5 5 5 298.15 273.11 110.56 273.11 298.15 110.56 1.916 10 kg/( m s)

4 28.7805 57.625 3.14159 0.1524 1.916 10 1000 7.2317 10 #

# Re =

Re = µ

  +

     +     =            ( ii) Create a regression equation to calculate Cd versus Re#. You may use any mathematical expression such as a least square polynomial or a power series. The regression equation must cover the flow range of Re# expected during testing.

( iii) The regression equation must predict Cd values within ± 0.5 % of the individual Cd values determined from calibration. 199 ( iv) If the ± 0.5 % criterion is met, transfer the regression equation to the SSV real time calculation system for use in emission tests as described in § 1065.642. Do not use the equation beyond the upper and lower calibration points used to determine the equation.

( v) If the ± 0.5 % criterion is not met for an individual data point, based upon good engineering judgment, you may omit data points and recalculate the regression equation, provided you use at least 7 points that meet the criterion. Do not use the equation beyond the upper and lower calibration points used to determine the equation. If omitting points does not resolve outliers, take corrective action. For example, check for leaks or repeat the calibration process. If you must repeat the process, we recommend applying tighter tolerances to measurements and allow more time for flows to stabilize.

( vi) CFV calibration. Calculate the mean and standard deviation of all the Cd as described in § 1065.602. If the standard deviation is less than or equal to 0.3 % of the mean, use the mean Cd in flow equations as described in § 1054.642, and use the CFV only down to the lowest inlet pressure measured during calibration. If the standard deviation exceeds 0.3 % of the mean, omit the data point collected at the lowest venturi inlet pressure. Recalculate the mean and standard deviation and determine if the new standard deviation is less than or equal to 0.3 % of the new mean. If it is, then use that mean Cd in flow calculations and use the CFV down to the lowest inlet pressure of the remaining data points. If the standard deviation still exceeds 0.3 % of the mean, continue omitting the data point at the lowest inlet pressure and recalculating the standard deviation and the mean. If the number of remaining data points becomes less than seven ( 7), take corrective action. For example, check for leaks or repeat the calibration process. If you must repeat the process, we recommend applying tighter tolerances to measurements and allow more time for flows to stabilize.

§ 1065.642 SSV, CFV, and PDP flow rate calculations. ( a) PDP flow rate. Based on the slopes and intercepts calculated in § 1065.640 for the speed that you operate your PDP during an emission test, calculate flow rate, as follows: n

200 1 0 1 0 3 :

755 rev/ min 98.575 kPa 8.314472 J/( mol K)

323.5 K 50.43 0.056 99.950 kPa 1000 ( J/ m )/ kPa 60 s/ min 50.43 99.950 98.575 755 98.5 in rev PDP in out in rev PDP in PDP in in out p t rev p V n f R T p p a V a f p Example f p R T a a p C C V =

  = +

= = = = = = =

=

=

  =

     3 0.056 75 0.06389 m / rev 98.575 0.06389 1000 755 8.314472 323.5 60 29.464 mol/ s rev V n n +

=

=

=

( b) SSV flow rate. Based on the Cd versus Re# regression you determined as described in § 1065.640, calculate SSV flow rate, during an emission test as follows: 201 n

( ) 1 2 6 1 2 4 2 10 0.998 0.00653 2 1 1 1 :

0.01824 m 99.132 kPa 1 28.7805 g/ mol 8.314472 J/ mol K 298.15 K 7. t in d f mix in d #

f SSV in t in mix in # A p n C C Z M R T C Re r C r p r p Example A p Z M R T Re

  =

=

          	   =

   =

= = = = = =

=

          ( ) ( )( ) 1.399 1 1.399 2 1.399 5 1 2 4 6 5 232 10 = 1.399 = 0.8 2.312 kPa 1000 g/ kg 1000 Pa/ kPa 2.312 1 99.132 0.977 2 1.399 1 0.977 1.399 1 0.977 0.8 0.274 10 0.998 0.00653 7.232 10 0.990 0.9 m p SSV SSV f f d d p C C r r C C C C n

    = = =

=

=

     =

 =

=

=

=

0.01824 99.132 1000 90 0.274 1 28.7805 8.314472 298.15 / 1000 58.173 mol/ s n =

202 ( c) CFV flow rate. Based on the mean Cd and other constants you determined as described in § 1065.640, calculate CFV flow rate, during an emission test as follows: n

2 :

0.985 0.7219 0.00456 m 98.836 kPa 1 28.7805 g/ mol 8.314472 J/ mol K 378.15 K = 1.399 = 0.7 1000 g/ kg 1000 Pa/ kPa 0.00456 98.836 10 0.985 0.7219 t in d fCFV mix in d fCFV t in mix in m p A p n C C Z M R T Example C C A p Z M R T C C n     =

= =

= = = = = =

= =

=

  00 1 28.7805 8.314472 378.15 / 1000 33.690 mol/ s n =

§ 1065.645 Amount of water in an ideal gas.

( a) For various emission calculations, you must calculate the amount of water in an ideal gas, . Based on the H2O x measured dewpoint, Tdew or frost point Tice and the triple point of water, T0, use the formulations of the World Meteorological Organization ( General Meteorological Standards and Recommended Practices, Appendix A, WMO Technical Regulations, WMO No. 49, 2000, incorporated by reference at § 1065.1010), to first calculate the pressure of water, pH2O in an ideal gas as follows: 203 ( ) ( ) ( )

( ) 0 0 0 0 8.2969 1 4 4.76955 1 3 0 10.79574 1 5.02800 log 1.50475 10 1 10 10 ^

0.42873 10 10 1 0.78614 10 273.16 :

9.5 9.5 273.15 282.65 Tdew T dew dew T Tdew T T T T sat dew dew p T K Example T C T K p

       +          	       +  +

 =

=

= = + =

( ) ( ) ( )

( ) 282.65 273.16 273.16 282.65 8.2969 1 4 273.16 282.65 282.65 273.16 4.76955 1 3 10.79574 1 5.02800 log 1.50475 10 1 10 10 ^ 0.42873 10 10 1 0.78614 10 1.186 sat satp kPa

       +        	       +  +

 =

=

And for frost point:

( ) ( ) ( )

( ) ( ) 0 0 0 0 0 0 273.16 273.16 2 257.75 257.75 10 ^ 9.09685 1 3.56654 log 0.87682 1 0.78614 10 273.16 :

15.4 15.4 273.15 257.75 10 ^ 9.09685 1 3.56654 log 0.87682 1 ice ice ice T T T T T T H2O ice ice H2O p T K Example T C T K p

      +   +     =

=

=   =   + =

     +   =

( ) 0 57.75 273.16 0.78614 10 0.1591 H2Op kPa

 +     = 204 The equation that uses dewpoint has been experimentally confirmed from ( 0 to 100)

C, and the same formula may be used over super cooled water from ( 50 to 0)

C with insignificant error. The equation for frostpoint is valid from ( 100 to 0)

C.

( b) You may also use other formulas to convert dewpoint or frostpoint to pH2O, provided that their use does not affect your ability to show compliance with the applicable standards. Formulas such as the commonly known the Goff Gratch formula may be used. Note however that the Wexler Greenspan formula that we previously specified is not valid for dewpoints below 0

C.

( c) To calculate the amount of water in an ideal gas, divide pH2O by the absolute pressure ( for example, barometric pressure) at which you measured dewpoint or frostpoint, as follows:

:

1.186 99.980 1.186 99.980 0.01186 mol/ mol sat H2O total sat total H2O H2O p x p Example p kPa p kPa x x =

= =

=

=

§ 1065.650 Emission calculations. ( a) General. Calculate brake specific emissions over each test interval in a duty cycle. Refer to the standardsetting part for any calculations you might need to determine a composite result, such as a calculation that weights and sums the results of individual test intervals in a duty cycle. We specify three ways to calculate brake specific emissions, as follows:

( 1) Calculate the total mass of emissions and then divide it by the total work generated over the test interval. In this section, we describe how to calculate the total mass of different emissions. We describe how to calculate total work. Divide the total mass by the total work to determine brake specific emissions, as follows: 205 :

64.975 g 25.783 kW hr 64.975 25.783 2.520 g/( kW hr) NOx NOx NOx m e W Example m W e e =

= =

=

=

( 2) For steady state testing, you may calculate the ratio of emission mass rate to power. In this special case you determine a mean mass rate of emissions during steady state operation, and then divide that rate by the steady state mean power. The result is a brake specific emission value calculated as follows:

:

2.885 mg/ s 54.342 kW 3600 s/ hr 1000 mg/ g 2.885 3600 54.342 1000 0.191 g/( kW hr) NMHC t m NMHC NMHC m e P Example m P C C e e =

=

= = =

=

=

   ( 3) Calculate the ratio of total mass to total work. This is a special case in which you use a signal linearly proportional to raw exhaust flow rate to determine a value proportional to total emissions. You then use the 206 same linearly proportional signal to determine total work using a chemical balance of fuel, intake air and exhaust as described in § 1065.655, plus information about your engine's brake specific fuel consumption. In this case we do not require any flow meter to be accurate, but we do require any flow meter you use must meet the applicable linearity and repeatability specifications in subpart D ( performance checks) or subpart J ( field testing) of this part. The result is a brake specific emission value calculated as follows:

:

805.5 g 52.102 kW hr 805.5 52.102 2.520 g/( kW hr) CO CO CO m e W Example m W e e =

=

=

=

=

   ( b) Total mass of emissions. To determine brake specific emissions for a test interval under paragraph ( a)( 1) of this section, calculate the total mass of each emission. To calculate the total mass of an emission, you multiply a concentration by its respective flow. Follow these steps to calculate total mass of emissions:

( 1) Concentration corrections and calculations. Before multiplying concentrations by a flow, perform the following calculations on recorded concentrations, in order, as follows:

( i) Correct all concentrations for drift, including dilution air background concentrations. Correct for drift as described in § 1065.657.

( ii) Optionally, correct all concentrations for instrument noise, including dilution air background concentrations. Correct for noise as described in § 1065.658.

( iii) Correct all concentrations measured on a " dry" basis to a " wet" basis, including dilution air background concentrations. Correct for drift as described in § 1065.659.

( iv) Calculate all NMHC concentrations, including dilution air background concentrations as described in § 1065.660.

( v) If you performed an emission test with an oxygenated fuel ( see subpart E or this part) calculate any NMHCE concentrations including dilution air background concentrations as described in § 1065.665.

( 2) Continuous sampling. For continuous sampling you frequently record a continuously updated concentration signal. You may measure this concentration from a changing flow rate or a constant flow rate, as follows:

( i) If you continuously sample from a changing exhaust flow rate, synchronously multiply it by the flow rate of the flow from which you extracted it. We consider the following flows changing flows that require a continuous multiplication of concentration times flow rate: raw exhaust, exhaust diluted with a constant flow rate of dilution air, and CVS dilution with a CVS flow meter that does not have an upstream heat exchanger or electronic flow control. Account for dispersion and time alignment as described in 207 § 1065.201. This multiplication results in the flow rate of the emission itself. Integrate the emission flow rate over a test interval to determine the total emission. If the total emission is a molar quantity, convert this quantity to a mass by multiplying it by its molar mass, M. The result is the mass of the emission, m. The following is a continuous sampling with variable flow example:

1 1 :

13.875389 g/ mol 1200 84.5 µ mol/ mol 86.0 µ mol/ mol 2.876 mol/ s 2.224 mol/ s 1 Hz 1000000 µ mol/ mol 1 1 s 1 13.875389 84.5 2.876 N i i i record NMHC NMHC1 NMHC2 exh1 exh2 record mol NMHC m M x n t t f Example M N x x n n f C t m = =

  =

= = = = = =

= =

  = =

=

( ) 1200 1200 86.0 2.224 ... 1 1000000 25.23 g NMHC exh NMHC x n m + ++ =

( ii) If you continuously sample from a constant exhaust flow rate, you may calculate the mean concentration recorded over the test interval and treat the mean as a batch sample ( e. g., bag sample) as described in paragraph ( b)( 3)( ii) of this section. We consider the following flows constant exhaust flows: CVS diluted exhaust with a CVS flow meter that has either an upstream heat exchanger, electronic flow control, or both.

( 3) Batch sampling. The concentration may also be a single concentration from a proportionally extracted batch sample ( e. g., a bag). In this case, you multiply the mean concentration of the batch sample by the total flow from which the sample was extracted. You may calculate total flow by integrating a changing flow rate or by determining the mean of a constant flow rate, as follows:

( i) If you batch sample from a changing exhaust flow rate, extract a sample proportional to the changing exhaust flow rate. We consider the following flows changing flows that require proportional sampling: raw exhaust, exhaust diluted with a constant flow rate of dilution air, and CVS dilution with a CVS flow meter that does not have an upstream heat exchanger or electronic flow control. Integrate the flow rate over a test interval to determine the total flow from which you extracted the proportional sample. 208 Multiply the mean concentration of the batch sample by the total flow from which the sample was extracted. If the total emission is a molar quantity, convert this quantity to a mass by multiplying it by its molar mass. If the total emission is a molar quantity, convert this quantity to a mass by multiplying it by its molar mass, M. The result is the mass of the emission, m. In the case of PM emissions, where the mean PM concentration is already in units of mass per mole of sample, , simply multiply the total PM M flow by . The result is the total mass of PM, . The following is a batch sample extracted from a PM M PM m variable flow rate example:

( ) 1 1 :

46.0055 g/ mol N= 9000 85.6 µ mol/ mol 25.534 mol/ s 26.950 mol/ s 5 Hz 1000000 µ mol/ mol 1 0.2 s 5 46.0055 85.6 25.534 26.950 ... N i i record NOx NOx dexh1 dexh2 record mol NOx dexh9000 m M x n t t f Example M x n n f C t m n = =

  =

=

= = = = =

  = =

= + ++

 0.2 1000000 4.201 g NOx m =   ( ii) If you batch sample from a constant exhaust flow rate, extract a sample at a constant flow rate. We consider the following flows constant exhaust flows: CVS diluted exhaust with a CVS flow meter that has either an upstream heat exchanger, electronic flow control, or both. Determine the mean flow rate from which you extracted the constant flow rate sample. Multiply the mean concentration of the batch sample by the mean flow rate of the exhaust from which the sample was extracted, and multiply the result by the time of the test interval. If the total emission is a molar quantity, convert this quantity to a mass by multiplying it by its molar mass, M. The result is the mass of the emission, m. In the case of PM emissions, where the mean PM concentration is already in units of mass per mole of sample, , PM M simply multiply the total flow by . The result is the total mass of PM, . PM M PM m ( iii) The following is a batch sample extracted from a constant flow rate example: 209 :

0 .1 4 4 m g / m o l 5 7 .6 9 2 m o l / s 2 0 m i n 6 0 s / m i n 1 0 0 0 m g / g 0 .1 4 4 5 7 .6 9 2 2 0 6 0 1 0 0 0 3 7 .6 6 1 g P M P M d e x h t m P M P M m M x n t M x M E x a m p l e M n t C C m m =

=

=

=   = = =

=

=

   ( 4) Diluted exhaust sampling; continuous or batch. If you sampled emissions from diluted exhaust, you must consider two additional steps.

( i) If you diluted a sample at a constant ratio of dilution air flow rate to exhaust flow rate ( raw or dilute), you must multiply your total mass emissions by the sum of the dilution ratio, DR, plus one. The following is an example of a secondary dilution system for sampling PM from a CVS: ( )

( ) 1 :

6.853 g 5 : 1 6.853 5 1 41.118 g PM PMdil PMdil PM PM m m DR Example m DR m m = +

= =

= +

=

( ii) You may optionally measure background emissions in dilution air by either continuous sampling or batch sampling. You may then subtract the background you would have otherwise attributed to your engine as described in § 1065.667.

( 5) Nox correction for intake air humidity. Correct the total mass of Nox based on intake air humidity as described in § 1065.670. Note that if you performed diluted exhaust sampling, perform this correction after correcting for any dilution air background.

( c) Total work. To determine brake specific emissions for a test interval as described in paragraph ( a)( 1) of this section, you must also calculate the total work. To calculate total work, multiply the feedback engine speed by its respective feedback torque and apply the appropriate units conversion factors. This results in the power of the engine. Integrate the power over a test interval to determine the total work. If your standard is in the units g/ hp

hr 210 use the following conversion factor: 1 hp = 550 ft lbf/ s = 0.77456999 kW, and round the resulting value. The following is an example:

1 2 1 :

9000 1800 .2 rev/ min 1805.8 rev/ min 1 7 7 .23 N m 1 7 5 .00 N m 2 rad/ rev 60 s/ min 1000 ( N m/ s)/ kW 5 Hz 3600 s/ h r 1800.2 1 7 7 .23 2 3.14159 60 1 N i i i ni i rec ord n1 n2 1 rev t1 p reco rd t2 1 W P t P f T t f examp le N f f T T C C C f C P =   = =

=

  =

= = = = = = = =

= =

( ) 9000 000 3 3 .41 kW 3 3 .09 kW 1 0 .2 s 5 3 3 .41 3 3 .09 ... 0.2 3600 1 6 .875 kW hr 1 2 P =

P t P W W =

  = =

+ + + =

=

( d) Steady state mass rate divided by power. To determine steady state brake specific emissions for a test interval as described in ( a)( 2) of this section, calculate the steady state mass rate of the emission. Then calculate the steady state power. Divide the mean mass rate of the emission by the mean power to determine steady state brakespecific emissions.

( 1) To calculate the mass rate of an emission, multiply its mean concentration ( e. g., ) by its respective mean x flow rate, . If the result is a molar flow rate, convert this quantity to a mass rate by multiplying it by its n

211 molar mass, M. The result is the mean mass rate of the emission, . In the case of PM emissions, where the m

mean PM concentration is already in units of mass per mole of sample, , simply multiply the mean flow PM M rate, by . The result is the mass rate of PM, . n

PM M PM m

( 2) To calculate power, multiply mean engine speed, , by its respective mean torque, , and apply the n f T appropriate units conversion factors. The results is the mean power of the engine, . P ( 3) Divide emission mass rate by power to calculate a brake specific emission result as described in paragraph ( a)( 2) of this section.

( 4) The following is an example of how to calculate mean mass rate and mean power:

:

28.0101 g/ mol 12.00 mmol/ mol 1.530 mol/ s 1000 mmol/ mol 3584.5 rev/ min 121.50 N m 2 rad/ rev 60 s/ min 1000 ( N m/ s)/ kW 28.0101 12.00 1.530 1000 0.514 g/ s 3584. n CO CO mol n rev t P m M x n P f T Examples M x n C f T C C C m m P   =

=

= =

= =

=

= = = =

=

=

=

5 121.50 2 1000 60 45.61 kW P   =     212 ( e) Ratio of total mass of emissions to total work. To determine brake specific emissions for a test interval as described in ( a)( 3) of this section, calculate a value proportional to the total mass of each emission. Divide each proportional value by a value that is similarly proportional to total work. The result is a brake specific emission.

( 1) Total mass. To determine a value proportional to the total mass of an emission, determine total mass as described in paragraph ( b) of this section, except substitute for the flow rate, , or the total flow, with a n

n signal that is linearly proportional to flow rate, or linearly proportional to total flow, .

n

 n

( 2) Total work. To calculate a value proportional to total work over a test interval, integrate a value that is proportional to power. Use information about the brake specific fuel consumption of your engine, efuel to convert a signal proportional to fuel flow rate to a signal proportional to power. To determine a signal proportional to fuel flow rate, divide a signal that is proportional to the mass rate of carbon products by the fraction of carbon in your fuel, wc.. For your fuel, you may use a measured wc or you may use the default values in Table 1 of § 1065.655. Calculate the mass rate of carbon from the amount of carbon and water in the exhaust, which you determine with a chemical balance of fuel, intake air, and exhaust as described in § 1065.655. In the chemical balance, you must use concentrations from the flow that generated the signal proportional to flow rate, , in paragraph ( e)( 1) of this section. The following is an example of how to n

 determine a signal proportional to total work over a test interval: 213 1 1 1 1 :

3000 5 Hz 285 g/( kW hr)

0.869 g/ g 12.0107 g/ mol 3.922 mol/ s 91.634 mmol/ mol N i i fueli i fuel C i Cproddryi fueli fuel H2Oi record record fuel fuel c 1 Cproddry1 H2O W P t m P e M n x m w x t f Example N f e w M n x x = =

=

= +

  =

= = =

=

=

= =

  91.634 98.005 1000 1000 1000 26.16 27.21 1000 1000 26.16 mmol/ mol 4.139 mol/ s 98.005 mmol/ mol 27.21 mmol/ mol 1000 mmol/ mol 3600 s/ hr 3.922 4.139 12.0107 ... 1 1 1 Cpdry3000 H 1 2 Cproddry2 H2O2 mol t x 3000 x n x x C C n + W =

= =

= = =

+ ++ + + =

1000 0.2 285 0.869 5.09 kW hr 2On3000 W

       =

  ( 3) Use the value proportional to total mass and the value proportional to total work to determine brakespecific emissions as described in paragraph ( a)( 3) of this section.

( f) Rounding. Round emission values only after all calculations are complete and the result is in g/ kW

hr or units equivalent to the units of the standard ( i. e., g/ hp

hr.). 214 ( 1) General. To replace a number having a given number of digits with a number having a smaller number of digits, follow these rules:

( i) If the digits to be discarded begin with a digit less than 5, the digit preceding the 5 is not changed. Example : 6.9749515 rounded to 3 digits is 6.97 ( ii) If the digits to be discarded begin with a 5 and at least one of the following digits is greater than 0, the digit preceding the 5 is increased by 1. Examples : 6.9749515 rounded to 2 digits is 7.0, 6.9749515 rounded to 5 digits is 6.9750 ( iii) If the digits to be discarded begin with a 5 and all of the following digits are 0, the digit preceding the 5 is unchanged if it is even and increased by 1 if it is odd. ( Note that this means that the final digit is always even.) Examples : 6.9749515 rounded to 7 digits is 6.974952, 6.974950 5 rounded to 7 digits is 6.974950.

( 2) Rounding converted numerical values. In most cases the product of the unconverted numerical value and a conversion factor will be a numerical value with a number of digits that exceeds the number of significant digits of the unconverted numerical value. Proper conversion procedure requires rounding this converted numerical value to the number of significant digits that is consistent with the maximum possible rounding error of the unconverted numerical value. Example : To express the value l = 36 ft in meters, use the factor 0.3048 and write l = 36 ft 3 0.3048 m/ ft = 10.9728 m = 11.0 m. The final result, l = 11.0 m, is based on the following reasoning: The numerical value '' 36'' has two significant digits, and thus a relative maximum possible rounding error ( abbreviated RE) of 0.5/ 36 = 1.4 % because it could have resulted from rounding the number 35.5, 36.5, or any number between 35.5 and 36.5. To be consistent with this RE, the converted numerical value '' 10.9728'' is rounded to 11.0 or three significant digits because the number 11.0 has an RE of 0.05/ 11.0 = 0.45 %. Although this 0.45 % RE is one third of the 1.4 % RE of the unconverted numerical value '' 36,'' if the converted numerical value '' 10.9728'' had been rounded to 11 or two significant digits, information contained in the unconverted numerical value '' 36'' would have been lost. This is because the RE of the numerical value '' 11'' is 0.5/ 11 = 4.5 %, which is three times the 1.4 % RE of the unconverted numerical value '' 36.'' This example therefore shows that when selecting the number of digits to retain in the numerical value of a converted quantity, one must often choose between discarding information or providing unwarranted information. Consideration of the end use of the converted value can often help one decide which choice to make. Note : Consider that one had been told initially that the value l = 36 ft had been rounded to the nearest inch. Then in this case, since l is known to within 1 in, the RE of the numerical value '' 36'' is 1 in/( 36 ft 3 12 in/ ft) = 0.23 %. Although this is less than the 0.45 % RE of the number 11.0, it is comparable to it. Therefore, the result l = 11.0 m is still given as the converted value. Note that the numerical value '' 10.97'' would give excessive unwarranted information because it has an RE that is one fifth of 0.23 %.

§ 1065.655 Chemical balances of fuel, intake air, and exhaust. ( a) General. Chemical balances of fuel, intake air, and exhaust may be used to calculate ratios of their flows, the amount of water in their flows, and the concentration of constituents in their flows. Along with the flow rate of either fuel, intake air, or exhaust you may use chemical balances to determine the flows of the other two. For example, you may use chemical balances along with exhaust flow to determine fuel flow and intake flow.

( b) Procedures that require chemical balances. We require chemical balances when you determine the following:

( 1) A value proportional to total work, , when you choose to determine brake specific emissions as W

described in § 1065.650( e).

( 2) The amount of water in a raw or diluted exhaust flow, xH2On, when you do not measure the amount of water in a flow to correct for the amount water removed, as described in § 1065.659( c)( 2).

( 3) The flow weighted average fraction of dilution air in diluted exhaust, , when you do not measure DF dilution air flow to correct for background emissions as described in § 1065.667( c). 215 ( c) Chemical balance procedure. The calculations for a chemical balance involve a system of equations that require iteration. We recommend using a computer to solve this system of equations. You must guess the initial values of up to three quantities: the amount of water in the measured flow, xH2O, fraction of dilution air in diluted exhaust, DF, and the amount of products on a C1 basis per dry mole of dry measured flow, xCproddry. For each emissions concentration, x, and amount of water xH2O, you must determine their completely dry concentrations. xdry and xH2Odry. You must also use your fuel's atomic hydrogen to carbon ratio, a, and oxygen to carbon ratio, b. For your fuel, you may measure a and b or you may use the default values in Table 1 of § 1065.650. Use the following steps to complete a chemical balance:

( 1) Convert your measured concentrations such as, xCO2meas, xNOmeas, and xH2Oint, to dry concentrations by dividing them by one minus the amount of water present during their respective measurements: xH2OxCO2, xH2OxNO, and xH2Oint. If the amount of water present during a " wet" measurement is the same as the unknown amount of water in the exhaust flow, xH2O, iteratively solve for that value in the system of equations. If you measure only total NOx and not NO and NO2 separately, use good engineering judgement to split your total NOx between NO and NO2 for the chemical balances. For example, if you measure emissions from a stoichiometric spark ignition engine, you may assume all NOx is NO. For a compression ignition engine, you may assume NOx is 75 % NO and 25 % NO2. For NO2 storage aftertreatment systems, you may assume NOx is 75 % NO2 and 25 % NO. Note that for emissions calculations you must use the molar mass of NO2 for the molar mass of all NOx, regardless of the actual NO2 fraction of NOx.

( 2) Enter the equations in ( c)( 3) into a computer program to iteratively solve for xH2O and xCproddry. If you measure raw exhaust flow, set DF equal to zero ( 0). If you measure diluted exhaust flow, iteratively solve for DF. Use good engineering judgment to guess initial values for xH2O, xCproddry, and DF . We recommend guessing an initial amount of water that is about twice the amount of water in your intake or dilution air. We recommend guessing an initial value of xCproddry as the sum of your measured CO2, CO, and THC values. If you measure diluted exhaust, we also recommend guessing an initial DF between 0.75 and 0.95, such as 0.8. Perform iteration until the most recently updated guesses are all within ± 1 % of their respective most recently calculated values.

( 3) In the equations that follow, we use the following symbols and subscripts: amount of water in measured flow amount of water per dry mole of measured flow amount of carbon products on a basis per dry mole of measured flow fraction of dilution air H2O H2Odry Cproddry 1 x x x C DF = =

=

= in measured flow assuming stoichiometric exhaust amount of dry stoichiometric products per dry mole of intake air amount of oxygen products on an basis per dry mole of measu prod/ intdry O2proddry 2 x x O =

=

[ ]

[ ]

[ ] red flow amount of emission per dry mole of measured flow amount of emission in measured flow amount of water at emission measurement location amo emission dry emission meas H2O emission meas H2Oint x x x x =

=

=

= unt of water in intake air amount of water in dilution air amount of oxygen per dry mole of air; 0.209445 mol/ mol amount of carbon dioxide per dry mole of air; 375 µ mol/ mol H2Odil O2airdry CO2airdry x x x   == =

=

= atomic hydrogen to carbon ratio in fuel = atomic oxygen to carbon ratio in fuel   216 ( )

( ) 1 1 2 1 1 1 1 1 1 1 2 2 H2Odry H2O H2Odry H2Ointdry H2Odry Cproddry H2Odildry prod/ intdry Cproddry CO2dry COdry THCdry O2proddry prod/ intdry H2Ointdry O2airdry prod/ intdry COdry x x x x x x DF DF x x x x x x x x DF x x x x DF     = +

= +  +

= + +

=   +

=

1 2 2 1 1 1 2 2 1 Cproddry NO2dry O2proddry CO2dry COdry Cproddry NOdry NO2dry Cproddry CO2airdry CO2meas CO2dry H2OCO2meas COdry Cproddry NO2dry COmeas COdry H2OCOmea x x x x x x x x x x x x x x x x x x x

 = + + + +       =

           =

1 1 1 1 1 s THCmeas THCdry H2OTHCmeas H2Oint H2Ointdry H2Oint H2Odil H2Odildry H2Odil NO2meas NO2dry H2ONO2meas NOmeas NOdry H2ONOmeas x x x x x x x x x x x x x x x =

=

=

=

=   217 ( 4) The following is an example; iteratively solved using the equations in paragraph ( c)( 3) of this section: ( )

( ) 35.24 1000 29.3 47.6 1000 1000 34.54 1000 17.22 1000 35.24 34.04 mmol/ mol 1 1.8 17.22 24.69 1 0.843 0.843 12.01 35.24 mmol/ mol 2 0.9338 24.614 24.69 mmol/ mol 0.9338 1 1 0.843 0.209445 H2O H2Odry Cproddry prod/ x x x DF x = = +

= +  + =

= + + =

=   + =

29.3 24.69 12.1 1000000 1000 1000000 29.3 50.4 12.1 1000 1000 1000 375 100 8.601 1000 1 0.9338 mol/ mol 1 1 1.8 1 1 0.843 2 2 1 1.8 24.614 24.69 0.05 24.69 34.54 mol/ mol 2 2 24.770 1 intdry O2proddry CO2dry x x = =

 = + + + +   =     =

0 29.3 24.69 12.1 1000000 1000 1000000 8.601 1000 34.04 1000 16.93 1000 11.87 10 24.614 mmol/ mol 1 1.8 1 2 2 29.0 29.3 µ mol/ mol 1 46 47.6 µ mol/ mol 1 16.93 17.22 mmol/ mol 1 11.87 1 COdry THCdry H2Ointdry H2Odildry x x x x =

           = =

= =

= =

=

00 8.601 1000 8.601 1000 12.01 mmol/ mol 12.0 12.1 µ mol/ mol 1 50.0 50.4 µ mol/ mol 1 0.209445 mol/ mol 375 µ mol/ mol = 1.8 = 0.05 NO2dry NOdry O2airdry CO2airdry x x x x     =

= =

= =

=

=

Table 1 of 1065.650: Default values of atomic hydrogen 218 to carbon ratio, a, and carbon mass fraction of fuel, wC, for various fuels:

§ 1065.657 Drift validation and correction. ( a) Determine if measurement instrument drift invalidates a test. Use the following quantities and calculation to determine if drift invalidates a test:

( 1) Span reference, xref.

( 2) Post test span check, xspanchk.

( 3) Post test zero check, xzerochk.

( 4) Flow weighted amount expected at either the standard or during a test interval, whichever is greater, xexp.

( 5) Calculate drift correction, as follows:

exp 5.2 1695.8 5.2 1800.0 435.5 1 2 :

1695.8 µ mol/ mol 5.2 µ mol/ mol 1800.0 µ mol/ mol 435.5 µ mol/ mol 1 0.033 3.3 % 2 zerochk spanchk zerochk ref x x x x x spanchk zerochk ref exp drift correction Example x x x x drift correction

      +   =

=

=   =

=

+   = = =

( b) You may correct every recorded amount for drift if drift did not invalidate the test. Use the following quantities and calculation to correct for drift:

( 1) The quantities from paragraph ( a) of this section.

( 2) Each recorded amount, xi or for batch sampling, . x ( 3) Correct for drift as follows: 219 ( )

( ) 5.2 1695.8 1800.0 3 2 :

1695.8 µ mol/ mol 5.2 µ mol/ mol 1800.0 µ mol/ mol or 435.5 µ mol/ mol 3 435.5 5.2 450.1 µ mo 2 zerochk spanchk ref x x i zerochk x idrift corrected spanchk zerochk ref i idrift corrected x x x Example x x x x x x

    +   =

=

=   =

=

+    = =

l/ mol § 1065.658 Noise correction. ( a) You may set to zero any recorded data point if that point's numerical value is smaller than the least of the following values:

( 1) The measurement instrument noise determined according to § 1065.305.

( 2) For lab instruments the recommended noise limit specified in Table 1 of § 1065.205.

( 3) For field testing instruments, the recommended noise limit specified in Table 1 of § 1065.915.

( b) If you perform this noise correction on samples that are corrected for background concentrations in dilution air, then noise correct the respective dilution air measurements the same way.

( c) If you perform this noise correction on a THC concentration that you use to determine NMHC, then correct the CH4 concentration the same way.

§ 1065.659 Removed water correction. ( a) If you remove water upstream of a concentration measurement, x, or upstream of a flow measurement, n, correct for the removed water. Perform this correction based on the amount of water at the concentration measurement, xH2O[ emission] meas, and at the flow meter, xH2O, whose flow is used to determine the concentration's total mass over a test interval.

( b) Downstream of where you removed water, you may determine the amount of water remaining by any of the following:

( 1) Measure the dewpoint temperature and absolute pressure downstream of the water removal location and then calculate the amount of water remaining as described in § 1065.645.

( 2) If you can justify assuming saturated water vapor conditions at a given location, you may use the measured temperature at that location as the dewpoint temperature.

( 3) You may also use a nominal value of absolute pressure based on an alarm setpoint, a pressure regulator setpoint, or good engineering judgment.

( c) For a corresponding concentration or flow measurement where you did not remove water, you may determine the amount of initial water by any of the following:

( 1) Use any of the techniques described in ( b). 220 ( 2) If the measurement is a raw exhaust measurement, you may determine the amount of water based on intake air humidity, plus a chemical balance of fuel, intake air and exhaust as described in § 1065.655.

( 3) If the measurement is a diluted exhaust measurement, you may determine the amount of water based on intake air humidity, dilution air humidity, and a chemical balance of fuel, intake air and exhaust as described in § 1065.655.

( d) Perform a removed water correction to the concentration measurement using the following calculation:

[ ] [ ] 1 1 :

29.0 µ mol/ mol 8.601 mmol/ mol 34.04 mmol/ mol 1000 mmol/ mol 34.04 1 1000 29.0 8.601 1 1000 28.3 µ mol/ mol H2O emission meas H2Oemission meas COmeas H2OCOmeas H2O mol CO CO x x x x Example x x x C x x

   =         = = = =

     =           =

§ 1065.660 THC and NMHC determination. ( a) THC determination. If we require you to determine THC emission, calculate xTHC using the initial THC contamination concentration xTHCinit from § 1065.520 as follows:

example:

150.3 µ mol/ mol 1.1 µ mol/ mol 150.3 1.1 149.2 µ mol/ mol THC THC THCinit THC THCinit THC THC x x x x x x x =

= = =

= 221 ( b) NMHC determination. Use one of the following to determine NMHC emission, , xNMHC ( 1) If you did not measure CH4, you may report xNMHC as 0.98

xTHC.

( 2) For nonmethane cutters, calculate xNMHC using the nonmethane cutter's penetration fractions ( PF) of CH4, and C2H6, from § 1065.331, and using the initial NMHC contamination concentration xNMHCinit from § 1065.520 as follows:

example:

150.3 µ mol/ mol 20.5 µ mol/ mol 0.980 0.050 1.1 µ mol/ mol 0.980 150 20 1.1 0.980 0.050 135.2 µ mol/ mol CH4 THC CH4 NMHC NMHCinit CH4 C2H6 THC CH4 CH4 C2H6 NMHCinit NMHC NMHC PF x x x x PF PF x x PF PF x x x     =

= = = = =     =

=

( 3) For gas a chromatograph, calculate xNMHC using the THC analyzer's response factor ( RF) CH4, from § 1065.366, and using the initial NMHC contamination concentration xNMHCinit from § 1065.520 as follows:

example:

145.6 µ mol/ mol 18.9 µ mol/ mol 0.970 1.1 µ mol/ mol 145.6 0.970 18.9 1.1 126.2 µ mol/ mol NMHC THC CH4 CH4 NMHCinit THC CH4 CH4 NMHCinit NMHC NMHC x x RF x x x x RF x x x =

= = = =

=

=

( 4) If the result of paragraph ( b)( 2) or ( 3) of this section is greater than the result of paragraph ( b)( 1) of this section, use the value calculated under paragraph ( b)( 1) of this section. 222 § 1065.665 THCE and NMHCE determination. ( a) If we require you to determine THCE, consider references to NMHC and NMHCE in this section to mean THC and THCE, respectively. If we require you to determine NMHCE, first determine NMHC as described in § 1065.660.

( b) If you measured an oxygenated hydrocarbon's mass concentration ( per mole of exhaust), then first calculate its molar concentration by dividing its mass concentration by the molar mass of the oxygenated hydrocarbon.

( c) Then multiply each oxygenated hydrocarbon's molar concentration by its respective number of carbon atoms per molecule. Add these carbon equivalent molar concentrations to the molar concentration of NMHC. The result is the molar concentration of NMHCE.

( d) For example, if you measured ethanol ( C2H5OH) and methanol ( CH3OH) as molar concentrations, and acetaldehyde ( C2H4O) and formaldehyde ( HCHO) as mass concentrations, you would determine NMHCE emissions as follows:

1 example:

127.3 µ mol/ mol 100.8 µ mol/ mol 25.5 µ mol/ mol 0.841 mg/ mol 39.0 µ g/ mol 44.05256 g/ mol 30.02598 g/ mol 0.841 i i i i N NMHCE NMHC OHC i exhOHC OHC OHC NMHC C2H5OH CH3OH exhC2H4O exhHCHO C2H4O HCHO C2H4O x x x M x M x x x M M M M x = = +

=

= = = = = = =

=

1000 19.1 µ mol/ mol 44.05256 39 1.3 µ mol/ mol 30.02598 127.3 2 100.8 25.5 2 19.1 1.3 393.9 µ mol/ mol HCHO NMHCE x x × =

= =

= + × + + × + =

§ 1065.667 Dilution air background emission correction. ( a) General. To determine the mass of background emissions to subtract from a diluted exhaust sample, first determine the total flow of dilution air, ndil, over the test interval. This may be a measured quantity or a quantity calculated from the diluted exhaust flow and the flow weighted average fraction of dilution air in diluted exhaust, 223 . Multiply the total flow of dilution air by the mean concentration of a background emission, . This may a DF dil x time weighted mean or a flow weighted mean ( e. g. a proportionally sampled background). The product of ndil and is the total amount of a background emission. If this is a molar quantity, convert it to a mass by dil x multiplying it by its molar mass, M. The result is the mass of the background emission, m. In the case of PM,

where the mean PM concentration is already in units of mass per mole of sample, , simply multiply the total PM M amount of dilution air by . The result is the total background mass of PM, . Subtract the total PM M PM m background mass from the total mass to correct for background emissions.

( b) You may determine the total flow of dilution air by a direct flow measurement. In this case calculate the total mass of background as described in § 1065.650( b), using the dilution air flow, ndil . Subtract the background mass from the total mass. Use the result in brake specific emissions calculations.

( c) You may determine the total flow of dilution air from the total flow of diluted exhaust and a chemical balance of the fuel, intake air and exhaust as described in § 1065.655. In this case calculate the total mass of background as described in § 1065.650( b), using the total flow of diluted exhaust, ndexh. Then multiply this result by the flowweighted average fraction of dilution air in diluted exhaust, . Calculate using flow weighted average DF DF concentrations of emissions in the chemical balance, as described in § 1065.655. You may assume that your engine operates stoichiometrically, even if it is a lean burn engine, such as a compression ignition engine. Note that for lean burn engines this assumption could result in an error in emissions calculations. This error could occur because the chemical balances in § 1065.655 correct excess air passing through a lean burn engine as if it was dilution air. If an emission concentration expected at the standard is about 100 times its dilution air background concentration, this error is negligible. However, if an emission concentration expected at the standard is similar to its background concentration, this error could be significant. If you are concerned about this error, we recommend that you remove background emissions from dilution air by HEPA filtration, chemical adsorption, or catalytic scrubbing. You might also consider using a partial flow dilution technique such as a bag mini diluter, which uses purified air as the dilution air. 224 ( d) The following is an example of using the flow weighted average fraction of dilution air in diluted exhaust,

. and the total mass of background emissions calculated using the total flow of diluted exhaust, ndexh, as DF described in § 1065.650( b) : :

46.0055 g/ mol 0.05 µ mol/ mol 23280.5 mol 0.843 1000000 µ mol/ mol 0.05 46.0055 23280.5 1000000 0.0536 g bkgnd bkgnddexh bkgnddexh bkgnd dexh NOx bkgnd dexh mol bkgndNOxdexh bkgndNOxdexh bkgn m DFm m Mx n Example M x n DF C m m m =

=

= =

=

= =

=

=

0.843 0.0536 0.0452 g dNOx bkgndNOx m =

=

§ 1065.670 NOx intake air humidity correction. ( a) Correct Nox concentrations for intake air humidity after applying all other corrections.

( b) For compression ignition engines correct for intake air humidity as follows or develop your own correction, based on good engineering judgment: 225 ( )

( ) 9.953 0.832 :

700.5 µ mol/ mol 0.022 mol/ mol 700.5 9.953 0.022 0.832 736.2 µ mol/ mol NOxcorr NOxuncorr H2O NOxuncorr H2O NOxcorr NOxcorr x x x Example x x x x =   +

= =

=   +

=

( c) For spark ignition engines you may use the same correction as for compression ignition engines, or you may develop your own correction, based on good engineering judgment.

§ 1065.672 CLD quench check calculations. ( a) Perform CLD quench check calculations as follows:

( 1) Calculate the amount of water in the span gas, xH2Ospan assuming complete saturation at the span gas temperature.

( 2) Estimate the expected amount of water, xH2Oexp in the exhaust you sample by considering the maximum expected amounts of water in combustion air, in fuel combustion products, and in dilution air if you dilute.

( 3) Calculate water quench as follows: 226 ( ) , ,

,

, 1 1 :

1800 µ mol/ mol 1760 µ mol/ mol 0.03 mol/ mol 0.017 mol/ mol 1480 µ mol/ mol H2Oexp CO2exp NO CO2 NO N2 NOwet H2Ocalc NOdry H2Ocalc NO N2 CO2meas NOdry NOwet H2Oexp H2Ocalc NO CO2 x x x x x quench x x x x x Example x x x x x x

   = +   +       =

= =

= =

( ) , 1500 µ mol/ mol 2.0 %

3.0 %

1760 0.03 1480 1500 2.0 1 0.017 1 1800 0.017 1500 3.0 0.0099 0.0089 1.88 % NO N2 CO2exp CO2meas x x quench quench =

=

=

 = +   +     =     =

§ 1065.690 PM sample media buoyancy correction. ( a) General. Correct PM sample media for their buoyancy in air if you weigh them on a balance. The buoyancy correction depends on the sample media density, the density of air, and the density of the calibration weight used to calibrate the balance. The buoyancy correction does not account for the buoyancy of the PM itself because the mass of PM typically accounts only for ( 0.01 to 0.10) % of the total weight. A correction to this small fraction of mass would be at the most ( 0.001 to 0.010) %.

( b) PM sample media density. Different PM sample media have different densities. Use the known density of your sample media, or use one of the densities for some common sampling media:

( 1) For PTFE coated borosilicate glass, use a sample media density: 2300 kg/ m3.

( 2) For PTFE membrane ( film) media with an integral support ring of polymethylpentene that accounts for 95 % of the media mass, use a sample media density: 920 kg/ m3.

( c) Air density. Because a PM balance environment must be tightly controlled to an ambient temperature of ( 22 ± 1)

C and a dewpoint of ( 9.5 ± 1)

C, air density is only a function of barometric pressure for this correction.

( d) Calibration weight density. Use the stated density of the material of your metal calibration weight. The example calculation in this section uses a density of 8000 kg/ m3, but you should know the density of your weight from the calibration weight supplier or the balance manufacturer if it is an internal weight. 227 ( e) Correction calculation. Buoyancy correct PM sample media using the following: ( )

( ) 2 3 1 1 @ 22 , 9.5 , /

1.1803 10 5.2922 10 :

100.0000 mg air weight corr uncorr air media air H2O air barom air H2O amb amb amb dew barom air barom uncorr m m M p p MM R T R T T CT Cp kPa p Example m p

       =             =

 = =

=

=

( ) 3 3 2 3 3 101.325 kPa 8000 kg/ m 920 kg/ m 1.1803 10 101.325 5.2922 10 1.1906 kg/ m 1.1906 1 8000 100.0000 1.1906 1 920 100.1147 mg barom weight media air air corr corr m m             =

=

=

=

=

     =           =

228 § 1065.695 Data requirements. ( a) To determine the information we require from engine tests, refer to the standard setting part and request from your Designated Compliance Officer the application format for certification. We may require different information for different purposes such as for certification applications, alternate procedure approval requests, selective enforcement audits, laboratory audits, production line test reports, and field test reports.

( b) See the standard setting part and § 1065.25 regarding recordkeeping.

( c) We may ask you the following about your testing:

( 1) What approved alternative procedures did you use? For example:

( i) Partial flow dilution for proportional PM.

( ii) CARB test procedures.

( iii) ISO test procedures.

( 2) What laboratory equipment did you use? For example, the make, model, and description of the following:

( i) Engine dynamometer and operator demand.

( ii) Probes, dilution, transfer lines, and sample preconditioning components.

( iii) Batch storage media ( e. g., bag material, PM filter material).

( 3) What measurement instruments did you use? For example, the make, model, and description of the following:

( i) Speed, torque instruments.

( ii) Flow meters.

( iii) Gas analyzers.

( iv) PM balance.

( 4) When did you conduct calibrations and performance checks and what were the results? For example, the dates and results of the following:

( i) Linearity checks.

( ii) Interference checks.

( iii) Response checks.

( iv) Leak checks.

( v) Flow meter checks.

( 5) What engine did you test? For example, the following:

( i) Manufacturer.

( ii) Family name on engine label.

( iii) Model.

( iv) Model year.

( v) Identification number.

( 6) How did you prepare and configure your engine for testing? For example, the following:

( i) Service accumulation; dates, hours, duty cycle and fuel.

( ii) Scheduled maintenance; dates and description.

( iii) Unscheduled maintenance; dates and description.

( iv) Intake restriction allowable pressure range.

( v) Charge air cooler volume.

( vi) Charge air cooler outlet temperature, specified engine conditions and location of temperature measurement.

( vi) Exhaust restriction allowable pressure range. 229 ( vii) Fuel temperature and location of measurement.

( viii) Any aftertreatment system configuration and description.

( ix) Any crankcase ventilation configuration and description ( e. g., open, closed, PCV, crankcase scavenged).

( 7) How did you test your engine? For example:

( i) Constant speed or variable speed.

( ii) Mapping procedure: step or sweep.

( ii) Continuous or batch sampling for each emission.

( iii) Raw or dilute; any dilution air background sampling.

( vi) Duty cycle and test intervals.

( vii) Cold start, hot start, warmed up running.

( viii) Intake and dilution air absolute pressure, temperature, dewpoint.

( ix) Simulated engine loads, curb idle transmission torque value.

( x) Warm idle speed value, any enhanced idle speed value.

( x) Simulated vehicle signals applied during testing.

( xi) Bypassed governor controls during testing.

( xi) Date, time, and location of test ( e. g., dynamometer laboratory identification).

( xi) Cooling medium for engine and charge air.

( xii) Operating temperatures: coolant, head, block.

( xiii) Full names of engine operators and laboratory operators.

( xiv) Natural or forced cool down and cool down time.

( xv) Cannister loading.

( 8) How did you validate your testing? For example, results from the following:

( i) Duty cycle regression statistics for each test interval.

( ii) Proportional sampling.

( iii) Drift.

( iv) Reference PM sample media in PM stabilization environment.

( 9) How did you calculate results? For example, results from the following:

( i) Drift correction.

( ii) Noise correction.

( iii) " Dry to wet" correction.

( iv) NMHC CH4 and contamination correction.

( v) Nox humidity correction.

( ii) Brake specific emission formulation: total mass divided by total work, mass rate divided by power, or ratio of mass to work.

( iii) Rounding emission results.

( 10) What were the results of your testing? For example:

( i) Maximum mapped power and speed at maximum power.

( ii) Maximum mapped torque and speed at maximum torque.

( iii) For constant speed engines: no load governed speed.

( iii) For constant speed engines: test torque.

( iv) For variable speed engines: test speed. 230 ( iv) Duty cycle and test interval brake specific emissions.

( v) Brake specific fuel consumption.

( 11) What fuel did you use? For example:

( i) Fuel that met specifications of subpart H of this part.

( ii) Alternative fuel.

( iii) Oxygenated fuel.

( 12) How did you field test your engine? For example:

( i) Data from paragraphs ( c)( 1), ( 3), ( 4), ( 5), and ( 9) of this section.

( ii) Probes, dilution, transfer lines, and sample preconditioning components.

( iii) Batch storage media ( e. g., bag material, PM filter material).

( iv) Continuous or batch sampling for each emission.

( v) Raw or dilute; any dilution air background sampling.

( vi) Cold start, hot start, warmed up running.

( vii) Intake and dilution air absolute pressure, temperature, dewpoint.

( viii) Curb idle transmission torque value.

( ix) Warm idle speed value, any enhanced idle speed value.

( x) Date, time, and location of test ( e. g., dynamometer laboratory identification).

( xi) Proportional sampling validation.

( xii) Drift validation.

( xiii) Operating temperatures: coolant, head, block.

( xiv) Full name of vehicle operator.

( xv) Full names of field test operators.

( xvi) Vehicle make, model, model year, identification number. 231 Subpart H   Engine Fluids, Test Fuels, and Analytical Gases § 1065.701 General requirements for test fuels. ( a) For all emission tests, use test fuels meeting the specifications in this subpart unless the standard setting part directs otherwise. If we do not specify a service accumulation fuel for a test engine, use a fuel typical of what you would expect the engine to use in service.

( b) If you produce engines that can run on a type of fuel ( or mixture of fuels) that we do not specify in this subpart, you must get our approval to test with fuel representing commercially available fuels of that type. We must approve your fuel specifications before you start testing.

( c) You may use a test fuel other than those we specify in this subpart if you do all the following:

( 1) Show that it is commercially available.

( 2) Show that your engines will use only the designated fuel in service.

( 3) Show that operating the engines on the fuel we specify would increase emissions or decrease durability.

( 4) Get our written approval before you start testing.

( d) We may allow you to use a different test fuel ( such as California Phase 2 gasoline) if you show us that using it does not affect your ability to comply with all applicable emission standards.

§ 1065.703 Distillate diesel fuel. ( a) Distillate diesel fuels for testing must be clean and bright, with pour and cloud points adequate for proper engine operation.

( b) There are three grades of # 2 diesel fuel specified for use as a test fuel. See the standard setting part to determine which grade to use. If the standard setting part does not specify which grade to use, use good engineering judgment to select the grade that represents the fuel on which the engines will operate in use. The three grades are specified in Table 1 of this section.

( c) You may use the following nonmetallic additives with distillate diesel fuels:

( 1) Cetane improver.

( 2) Metal deactivator.

( 3) Antioxidant, dehazer.

( 4) Rust inhibitor.

( 5) Pour depressant.

( 6) Dye.

( 7) Dispersant.

( 8) Biocide. 232 Table 1 of § 1065.705   Test Fuel Specifications for Distillate Diesel Fuel Item Units Ultra Low Sulfur Low Sulfur High Sulfur Reference Procedure 1 Cetane Number   40 50 40 50 40 50 ASTM D 613 03b Distillation range:

Initial boiling point 10 pct. point 50 pct. point 90 pct. point Endpoint ° C 171 204 204 238 243 282 293 332 321 366 171 204 204 238 243 282 293 332 321 366 171 204 204 238 243 282 293 332 321 366 ASTM D 86 03 Gravity ° API 32 37 32 37 32 37 ASTM D 287 92 Total sulfur mg/ kg 7 15 300 500 2000 4000 ASTM D 2622 03 Aromatics, minimum. ( Remainder shall be paraffins, naphthalenes, and olefins) g/ kg 100 100 100 ASTM D 5186 03 Flashpoint, min. ° C 54 54 54 ASTM D 93 02a Viscosity cSt 2.0 3.2 2.0 3.2 2.0 3.2 ASTM D 445 03 1All ASTM standards are incorporated by reference in § 1065.1010.

§ 1065.703 Residual fuel. [ Reserved]

§ 1065.710 Gasoline. ( a) Gasoline for testing must have octane values that represent commercially available fuels for the appropriate application. 233 ( b) There are two grades of gasoline specified for use as a test fuel. If the standard setting part requires testing with fuel appropriate for low temperatures, use the test fuel specified for low temperature testing. Otherwise, use the test fuel specified for general testing. The two grades are specified in Table 1 of this section.

Table 1 of § 1065.710   Test Fuel Specifications for Gasoline Item Units General Testing Low Temperaturee Testing Reference Procedure1 Distillation Range:

Initial boiling point 10% point 50% point 90% point End point

C ( 23.9  35.0) 2 ( 48.9  57.2)

( 93.3  110.0)

( 148.9  162.8)

Maximum, 212.8 ( 24.4  35.6)

( 36.7  47.8)

( 81.7  101.1)

( 157.8  174.4)

Maximum, 211.7 ASTM D 86 01 Hydrocarbon composition:

1. Olefins 2. Aromatics 3. Saturates µ m3/ m3 Maximum, 100,000 Maximum, 350,000 Remainder Maximum, 175,000 Maximum, 304,000 Remainder ASTM D 1319 02 Lead ( organic) g/ liter Maximum, 0.013 Maximum, 0.013 ASTM D 3237 97 Phosphorous g/ liter Maximum, 0.0013 Maximum, 0.005 ASTM D 3231 02 Total sulfur mg/ kg Maximum, 80 Maximum, 80 ASTM D 1266 98 Volatility ( Reid Vapor Pressure) kPa ( 60.0  63.4) 2,3 ( 77.2  81.4) ASTM D 323 99a 1 All ASTM standards are incorporated by reference in § 1065.1010.

2 For testing at altitudes above 1 219 m, the specified volatility range is ( 52 to 55) kPa and the specified initial boiling point range is ( 23.9 to 40.6)

C.

3 For testing unrelated to evaporative emissions, the specified range is ( 55 to 63) kPa.

§ 1065.715 Natural gas. ( a) Natural gas for testing must meet the specifications in the following table: 234 Table 1 of § 1065.715   Test Fuel Specifications for Natural Gas Item Reference Procedure1 Value 1. Methane, CH 4 ASTM D 1945 96 Minimum, 87.0 µ mol/ mol 2. Ethane, C 2 H 6 ASTM D 1945 96 Maximum, 5.5 µ mol/ mol 3. Propane, C 3 H 8 ASTM D 1945 96 Maximum, 1.2 µ mol/ mol 4. Butane, C 4 H 10 ASTM D 1945 96 Maximum, 0.35 µ mol/ mol 5. Pentane, C 5 H 12 ASTM D 1945 96 Maximum, 0.13 µ mol/ mol 6. C 6 and higher ASTM D 1945 96 Maximum, 0.1 µ mol/ mol 7. Oxygen ASTM D 1945 96 Maximum, 1.0 µ mol/ mol 8. Inert gases ( sum of CO 2 and N 2) ASTM D 1945 96 Maximum, 5.1 µ mol/ mol 1 All ASTM standards are incorporated by reference in § 1065.1010.

( b) At ambient conditions, natural gas must have a distinctive odor detectable down to a concentration in air not more than one fifth the lower flammability limit.

§ 1065.720 Liquefied petroleum gas. 235 ( a) Liquefied petroleum gas for testing must meet the specifications in the following table:

Table 1 of § 1065.720   Test Fuel Specifications for Liquefied Petroleum Gas Item Reference Procedure1 Value 1. Propane, C 3 H 8 ASTM D 2163 91 Minimum, 850,000 µ m3/ m3 2. Vapor pressure at 38

C ASTM D 1267 02 or 2598 022 Maximum, 1400 kPa 3. Volatility residue ( evaporated temperature, 35

C) ASTM D 1837 02 Maximum,  38

C 4. Butanes ASTM D 2163 91 Maximum, 50,000 µ m3/ m3 5. Butenes ASTM D 2163 91 Maximum, 20,000 µ m3/ m3 6. Pentenes and heavier ASTM D 2163 91 Maximum, 5,000 µ m3/ m3 7. Propene ASTM D 2163 91 Maximum, 100,000 µ m3/ m3 8. Residual matter ( residue on evap. of 100) ml oil stain ASTM D 2158 02 Maximum, 0.05 ml pass 3 9. Corrosion, copper strip ASTM D 1838 91 Maximum, No. 1 10. Sulfur ASTM D 2784 98 Maximum, 80 mg/ kg 11. Moisture content ASTM D 2713 91 pass 1 All ASTM standards are incorporated by reference in § 1065.1010.

2 If these two test methods yield different results, use the results from ASTM D 1267 02.

3 The test fuel must not yield a persistent oil ring when you add 0.3 ml of solvent residue mixture to a filter paper in 0.1 ml increments and examine it in daylight after two minutes.

( a) At ambient conditions, liquefied petroleum gas must have a distinctive odor detectable down to a concentration in air not more than one fifth the lower flammability limit.

§ 1065.740 Lubricants. ( a) Use commercially available lubricating oil that represents the oil that will be used in your engine in use.

( b) You may use lubrication additives, up to the levels that the additive manufacturer recommends.

§ 1065.745 Coolants. ( a) You may use commercially available antifreeze mixtures or other coolants that will be used in your engine in use.

( b) For laboratory testing of liquid cooled engines, you may use water with or without rust inhibitors.

( c) For coolants allowed in paragraphs ( a) and ( b) of this section, you may use rust inhibitors and additives required for lubricity, up to the levels that the additive manufacturer recommends.

§ 1065.750 Analytical Gases. Analytical gases must meet the accuracy and purity specifications of this section, unless you can show that other specifications would not affect your ability to show that your engines comply with all applicable emission standards. 236 ( a) Subparts C and D of this part refer to the following gas specifications:

( 1) Use purified gases to zero measurement instruments and to blend with calibration gases. Use gases with contamination up to the highest of the following values in the gas cylinder or at the outlet of a zero gas generator:

( i) 2 % contamination, measured relative to the flow weighted average concentration expected at the standard.

( ii) 2 % contamination, measured relative to the flow weighted average concentration measured during testing.

( iii) Contamination as specified in the following table:

Table 1 of § 1065.750   General specifications for purified gases Constituent Purified Air1 Purified N2 1 THC ( C1 equivalent) < 0.05

mol/ mol < 0.05

mol/ mol CO < 0.10

mol/ mol < 0.10

mol/ mol CO2 < 400

mol/ mol < 1.0

mol/ mol H2O < 5

mol/ mol < 5

mol/ mol O2 0.20 to 0.21 mol/ mol < 2

mol/ mol NOx < 0.02

mol/ mol < 0.02

mol/ mol 1 These are commonly designated as " ultra zero air monitoring" or " UZAM ."

( 2) Use the following gases with a flame ionization detector ( FID) analyzer:

( i) Use FID fuel with an H2 concentration of ( 0.4 ± 0.01) mol/ mol, balance He. Make sure the mixture contains no more than 0.05

mol/ mol THC and no more than 400

mol/ mol CO2.

( ii) Use FID burner air that meets the specifications of purified air in paragraph ( a)( 1) of this section.

( iii) Zero flame ionization detectors with purified air meeting the specifications in paragraph ( a)( 1) of this section.

( 3) Use the following gas mixtures, with gases traceable within ± 1 % of the NIST true value or other gas standards we approve:

( i) CH4, balance purified synthetic air or N2.

( ii) C2H6, balance purified synthetic air or N2.

( iii) C3H8, balance purified synthetic air or N2.

( iv) CO, balance purified N2.

( v) CO2, balance purified N2.

( vi) NO, balance purified N2.

( vii)) NO2, balance purified N2.

( viii) O2, balance purified N2.

( ix) C3H8, CO, CO2, NO, balance purified N2.

( 4) You may use gases for species other than those listed in paragraph ( b)( 3) of this section ( such as methanol in air, which you may use to determine response factors), as long as they are traceable to ± 1 % of the NIST true value or other similar standards we approve.

( 5) You may generate your own calibration gases using a precision blending device, such as a gas divider, to dilute gases with purified N2 or purified synthetic air. Gas dividers must meet the specifications in § 1065.248. 237 ( b) Record the concentration of any calibration gas standard and its expiration date specified by the gas supplier. Do not use any calibration gas standard after its expiration date.

( c) Transfer gases from their source to analyzers using components that are dedicated to controlling and transferring only those gases. For example, do not use a regulator, valve, or transfer line for zero gas if those components were previously used to transfer a different gas mixture. We recommend that you label regulators, valves, and transfer lines to prevent contamination. Note that even small traces of a gas mixture in the dead volume of a regulator, valve, or transfer line can diffuse upstream into a high pressure volume of gas, which would contaminate the entire high pressure gas source, such as a compressed gas cylinder.

§ 1065.790 Mass standards. ( a) PM balance calibration weights. Use PM balance calibration weights that are certified as traceable to NIST standards to within 0.1 % uncertainty. Calibration weights may be certified by any calibration lab that maintains NIST traceability. Make sure your lowest calibration weight has no greater than ten times the mass of an unused PM sample medium.

( b) Dynamometer calibration weights. [ Reserved].