and continuous monitoring of chiller temperature, Tchiller.
If you do not continuously record values of Tchiller, you
may use its peak value observed during a test, or its alarm setpoint,
as a constant value to determine a constant amount of water according
to Sec.  1065.645. If it is valid to assume that Tchiller is
equal to Tdew, you may use Tchiller in lieu of
Tdew according to Sec.  1065.645. If it is valid to assume a
constant temperature offset between Tchiller and
Tdew, due to a known and fixed amount of sample reheat
between the chiller outlet and the temperature measurement location,
you may factor in this assumed temperature offset value into emission
calculations. If we ask for it, you must show by engineering analysis
or by data the validity of any assumptions allowed by this paragraph
(d)(2)(ii).
    (3) Sample pumps. You may use sample pumps upstream of an analyzer
or storage medium for any gas. Use sample pumps with inside surfaces of
300 series stainless steel, PTFE, or any other material that you
demonstrate has better properties for emission sampling. For some
sample pumps, you must control temperatures, as follows:

    (i) If you use a NOX sample pump upstream of either an
NO2-to-NO converter that meets Sec.  1065.378 or a chiller
that meets Sec.  1065.376, it must be heated to prevent aqueous
condensation.
    (ii) For testing compression-ignition engines, 2-stroke spark-
ignition engines, or 4-stroke spark-ignition engines below 19 kW, if
you use a THC sample pump upstream of a THC analyzer or storage medium,
its inner surfaces must be heated to a tolerance of (191 11) [deg]C.
    (4) Ammonia Scrubber. You may use ammonia scrubbers for any or all
gaseous sampling systems to prevent interference with NH3,
poisoning of the NO2-to-NO converter, and deposits in the
sampling system or analyzers. Follow the ammonia scrubber
manufacturer's recommendations or use good engineering judgment in
applying ammonia scrubbers.
    (e) Optional sample-conditioning components for PM sampling. You
may use the following sample-conditioning components to prepare PM
samples for analysis, as long as you do not install or use them in a
way that adversely affects your ability to show that your engines
comply with the applicable PM emission standards. You may condition PM
samples to minimize positive and negative biases to PM results, as
follows:
    (1) PM preclassifier. You may use a PM preclassifier to remove
large-diameter particles. The PM preclassifier may be either an
inertial impactor or a cyclonic separator. It must be constructed of
300 series stainless steel. The preclassifier must be rated to remove
at least 50% of PM at an aerodynamic diameter of 10 [mu]m and no more
than 1% of PM at an aerodynamic diameter of 1 [mu]m over the range of
flow rates for which you use it. Follow the preclassifier
manufacturer's instructions for any periodic servicing that may be
necessary to prevent a buildup of PM. Install the preclassifier in the
dilution system downstream of the last dilution stage. Configure the
preclassifier outlet with a means of bypassing any PM sample media so
the preclassifier flow may be stabilized before starting a test. Locate
PM sample media within 75 cm downstream of the preclassifier's exit.
You may not use this preclassifier if you use a PM probe that already
has a preclassifier. For example, if you use a hat-shaped preclassifier
that is located immediately upstream of the probe in such a way that it
forces the sample flow to change direction before entering the probe,
you may not use any other preclassifier in your PM sampling system.
    (2) Other components. You may request to use other PM conditioning
components upstream of a PM preclassifier, such as components that
condition humidity or remove gaseous-phase hydrocarbons from the
diluted exhaust stream. You may use such components only if we approve
them under Sec.  1065.10.

0
61. Section 1065.170 is amended by revising the introductory text and
paragraphs (a) and (c)(1) to read as follows:

Sec.  1065.170  Batch sampling for gaseous and PM constituents.

    Batch sampling involves collecting and storing emissions for later
analysis. Examples of batch sampling include collecting and storing
gaseous emissions in a bag or collecting and storing PM on a filter.
You may use batch sampling to store emissions that have been diluted at
least once in some way, such as with CVS, PFD, or BMD. You may use
batch-sampling to store undiluted emissions.
    (a) Sampling methods. If you extract from a constant-volume flow
rate, sample at a constant-volume flow rate as follows:
    (1) Validate proportional sampling after an emission test as
described in Sec.  1065.545. Use good engineering judgment to select
storage media that will not significantly change measured emission
levels (either up or down). For example, do not use sample bags for
storing emissions if the bags are permeable with respect to emissions
or if they offgas emissions to the extent that it affects your ability
to demonstrate compliance with the applicable gaseous emission
standards. As another example, do not use PM filters that irreversibly
absorb or adsorb gases to the extent that it affects your ability to
demonstrate compliance with the applicable PM emission standard.
    (2) You must follow the requirements in Sec.  1065.140(e)(2)
related to PM dilution ratios. For each filter, if you expect the net
PM mass on the filter to exceed 400 [mu]g, assuming a 38 mm diameter
filter stain area, you may take the following actions in sequence:
    (i) First, reduce filter face velocity as needed to target a filter
loading of 400 [mu]g, down to 50 cm/s or less.
    (ii) Then, for discrete-mode testing only, you may reduce sample
time as needed to target a filter loading of 400 [mu]g, but not below
the minimum sample time specified in the standard-setting part.
    (iii) Then, increase overall dilution ratio above the values
specified in Sec.  1065.140(e)(2) to target a filter loading of 400
[mu]g.
* * * * *
    (c) * * *
    (1) If you use filter-based sampling media to extract and store PM
for measurement, your procedure must meet the following specifications:
    (i) If you expect that a filter's total surface concentration of PM
will exceed 400 [mu]g, assuming a 38 mm diameter filter stain area, for
a given test interval, you may use filter media with a minimum initial
collection efficiency of 98%; otherwise you must use a filter media
with a minimum initial collection efficiency of 99.7%. Collection
efficiency must be measured as described in ASTM D2986-95a
(incorporated by reference in Sec.  1065.1010), though you may rely on
the sample-media manufacturer's measurements reflected in their product
ratings to show that you meet this requirement.
    (ii) The filter must be circular, with an overall diameter of 46.50
 0.6 mm and an exposed diameter of at least 38 mm. See the
cassette specifications in paragraph (c)(1)(vii) of this section.
    (iii) We highly recommend that you use a pure PTFE filter material
that does not have any flow-through support bonded to the back and has
an overall thickness of 40  20 [mu]m. An inert polymer ring
may be bonded to the periphery of the filter material for support and
for sealing between the filter cassette parts. We consider
Polymethylpentene (PMP) and PTFE inert materials for a support ring,
but other inert materials may be used. See the cassette specifications
in paragraph (c)(1)(vii) of this section. We allow the use of PTFE-
coated glass fiber filter material, as long as this filter media
selection does not affect your ability to demonstrate compliance with
the applicable standards, which we base on a pure PTFE filter material.
Note that we will use pure PTFE filter material for compliance testing,
and we may require you to use pure PTFE filter material for any
compliance testing we require, such as for selective enforcement
audits.
    (iv) You may request to use other filter materials or sizes under
the provisions of Sec.  1065.10.
    (v) To minimize turbulent deposition and to deposit PM evenly on a
filter, use a 12.5[deg] (from center) divergent cone angle to
transition from the transfer-line inside diameter to the exposed
diameter of the filter face. Use 300 series stainless steel for this
transition.
    (vi) Maintain a filter face velocity near 100 cm/s with less than
5% of the recorded flow values exceeding 100 cm/s, unless you expect
either the net PM mass on the filter to exceed 400 [mu]g, assuming a 38
mm diameter filter stain area. Measure face velocity as the volumetric
flow rate of the sample at the

pressure upstream of the filter and temperature of the filter face as
measured in Sec.  1065.140(e), divided by the filter's exposed area.
You may use the exhaust stack or CVS tunnel pressure for the upstream
pressure if the pressure drop through the PM sampler up to the filter
is less than 2 kPa.
    (vii) Use a clean cassette designed to the specifications of Figure
1 of Sec.  1065.170 and made of any of the following materials:
DelrinTM, 300 series stainless steel, polycarbonate,
acrylonitrile-butadiene-styrene (ABS) resin, or conductive
polypropylene. We recommend that you keep filter cassettes clean by
periodically washing or wiping them with a compatible solvent applied
using a lint-free cloth. Depending upon your cassette material, ethanol
(C2H5OH) might be an acceptable solvent. Your
cleaning frequency will depend on your engine's PM and HC emissions.
    (viii) If you store filters in cassettes in an automatic PM
sampler, cover or seal individual filter cassettes after sampling to
prevent communication of semi-volatile matter from one filter to
another.
* * * * *

0
62. Section 1065.190 is amended by revising paragraphs (c), (e), (f)
and (g) to read as follows:

Sec.  1065.190  PM-stabilization and weighing environments for
gravimetric analysis.

* * * * *
    (c) Verify the cleanliness of the PM-stabilization environment
using reference filters, as described in Sec.  1065.390(d).
* * * * *
    (e) Verify the following ambient conditions using measurement
instruments that meet the specifications in subpart C of this part:
    (1) Continuously measure dewpoint and ambient temperature. Use
these values to determine if the stabilization and weighing
environments have remained within the tolerances specified in paragraph
(d) of this section for at least 60 min. before weighing sample media
(e.g., filters). We recommend that you use an interlock that
automatically prevents the balance from reporting values if either of
the environments have not been within the applicable tolerances for the
past 60 min.
    (2) Continuously measure atmospheric pressure within the weighing
environment. An acceptable alternative is to use a barometer that
measures atmospheric pressure outside the weighing environment, as long
as you can ensure that atmospheric pressure at the balance is always
within 100 Pa of that outside environment during weighing
operations. Record atmospheric pressure as you weigh filters, and use
these pressure values to perform the buoyancy correction in Sec.
1065.690.
    (f) We recommend that you install a balance as follows:
    (1) Install the balance on a vibration-isolation platform to
isolate it from external noise and vibration.
    (2) Shield the balance from convective airflow with a static-
dissipating draft shield that is electrically grounded.
    (3) Follow the balance manufacturer's specifications for all
preventive maintenance.
    (4) Operate the balance manually or as part of an automated
weighing system.
    (g) Minimize static electric charge in the balance environment, as
follows:
    (1) Electrically ground the balance.
    (2) Use 300 series stainless steel tweezers if PM sample media
(e.g., filters) must be handled manually.
    (3) Ground tweezers with a grounding strap, or provide a grounding
strap for the operator such that the grounding strap shares a common
ground with the balance. Make sure grounding straps have an appropriate
resistor to protect operators from accidental shock.
    (4) Provide a static-electricity neutralizer that is electrically
grounded in common with the balance to remove static charge from PM
sample media (e.g., filters), as follows:
    (i) You may use radioactive neutralizers such as a Polonium
(210Po) source. Replace radioactive sources at the intervals
recommended by the neutralizer manufacturer.
    (ii) You may use other neutralizers, such as corona-discharge
ionizers. If you use a corona-discharge ionizer, we recommend that you
monitor it for neutral net charge according to the ionizer
manufacturer's recommendations.
    (5) We recommend that you use a device to monitor the static charge
of PM sample media (e.g., filter) surface.
    (6) We recommend that you neutralize PM sample media (e.g.,
filters) to within 2.0 V of neutral. Measure static
voltages as follows:
    (i) Measure static voltage of PM sample media (e.g., filters)
according to the electrostatic voltmeter manufacturer's instructions.
    (ii) Measure static voltage of PM sample media (e.g., filters)
while the media is at least 15 cm away from any grounded surfaces to
avoid mirror image charge interference.

0
63. Section 1065.195 is amended by revising paragraphs (a) and (c)(4)
to read as follows:

Sec.  1065.195  PM-stabilization environment for in-situ analyzers.

    (a) This section describes the environment required to determine PM
in-situ. For in-situ analyzers, such as an inertial balance, this is
the environment within a PM sampling system that surrounds the PM
sample media (e.g., filters). This is typically a very small volume.
* * * * *
    (c) * * *
    (4) Absolute pressure. Use good engineering judgment to maintain a
tolerance of absolute pressure if your PM measurement instrument
requires it.
* * * * *

Subpart C--[Amended]

0
64. Section 1065.201 is amended by revising paragraphs (a) and (b) and
adding paragraph (h) to read as follows:

Sec.  1065.201  Overview and general provisions.

    (a) Scope. This subpart specifies measurement instruments and
associated system requirements related to emission testing in a
laboratory or similar environment and in the field. This includes
laboratory instruments and portable emission measurement systems (PEMS)
for measuring engine parameters, ambient conditions, flow-related
parameters, and emission concentrations.
    (b) Instrument types. You may use any of the specified instruments
as described in this subpart to perform emission tests. If you want to
use one of these instruments in a way that is not specified in this
subpart, or if you want to use a different instrument, you must first
get us to approve your alternate procedure under Sec.  1065.10. Where
we specify more than one instrument for a particular measurement, we
may identify which instrument serves as the reference for comparing
with an alternate procedure.
* * * * *
    (h) Recommended practices. This subpart identifies a variety of
recommended but not required practices for proper measurements. We
believe in most cases it is necessary to follow these recommended
practices for accurate and repeatable measurements and we intend to
follow them as much as possible for our testing. However, we do not
specifically require you to follow these recommended practices to
perform a valid test, as long as you meet the required calibrations and
verifications of measurement systems specified in subpart D of this
part.

0
65. Section 1065.210 is amended by revising paragraph (a) before the
figure to read as follows:

Sec.  1065.210  Work input and output sensors.

    (a) Application. Use instruments as specified in this section to
measure work inputs and outputs during engine operation. We recommend
that you use sensors, transducers, and meters that meet the
specifications in Table 1 of Sec.  1065.205. Note that your overall
systems for measuring work inputs and outputs must meet the linearity
verifications in Sec.  1065.307. We recommend that you measure work
inputs and outputs where they cross the system boundary as shown in
Figure 1 of Sec.  1065.210. The system boundary is different for air-
cooled engines than for liquid-cooled engines. If you choose to measure
work before or after a work conversion, relative to the system
boundary, use good engineering judgment to estimate any work-conversion
losses in a way that avoids overestimation of total work. For example,
if it is impractical to instrument the shaft of an exhaust turbine
generating electrical work, you may decide to measure its converted
electrical work. As another example, you may decide to measure the
tractive (i.e., electrical output) power of a locomotive, rather than
the brake power of the locomotive engine. In these cases, divide the
electrical work by accurate values of electrical generator efficiency
([eta]<1), or assume an efficiency of 1 ([eta]=1), which would over-
estimate brake-specific emissions. For the example of using locomotive
tractive power with a generator efficiency of 1 ([eta]=1), this means
using the tractive power as the brake power in emission calculations.
Do not underestimate any work conversion efficiencies for any
components outside the system boundary that do not return work into the
system boundary. And do not overestimate any work conversion
efficiencies for components outside the system boundary that do return
work into the system boundary. In all cases, ensure that you are able
to accurately demonstrate compliance with the applicable standards.
* * * * *

0
66. Section 1065.215 is amended by revising paragraph (e) to read as
follows:

Sec.  1065.215  Pressure transducers, temperature sensors, and dewpoint
sensors.

* * * * *
    (e) Dewpoint. For PM-stabilization environments, we recommend
chilled-surface hygrometers, which include chilled mirror detectors and
chilled surface acoustic wave (SAW) detectors. For other applications,
we recommend thin-film capacitance sensors. You may use other dewpoint
sensors, such as a wet-bulb/dry-bulb psychrometer, where appropriate.

0
67. Section 1065.220 is amended by revising paragraph (d) to read as
follows:

Sec.  1065.220  Fuel flow meter.

* * * * *
    (d) Flow conditioning. For any type of fuel flow meter, condition
the flow as needed to prevent wakes, eddies, circulating flows, or flow
pulsations from affecting the accuracy or repeatability of the meter.
You may accomplish this by using a sufficient length of straight tubing
(such as a length equal to at least 10 pipe diameters) or by using
specially designed tubing bends, straightening fins, or pneumatic
pulsation dampeners to establish a steady and predictable velocity
profile upstream of the meter. Condition the flow as needed to prevent
any gas bubbles in the fuel from affecting the fuel meter.

0
68. Section 1065.265 is amended by revising paragraph (c) to read as
follows:

Sec.  1065.265  Nonmethane cutter.

* * * * *
    (c) Configuration. Configure the nonmethane cutter with a bypass
line if it is needed for the verification described in Sec.  1065.365.
* * * * *

0
69. Section 1065.270 is amended by revising paragraphs (c) and (d)
introductory text to read as follows:

Sec.  1065.270  Chemiluminescent detector.

* * * * *
    (c) NO2-to-NO converter. Place upstream of the CLD an internal or
external NO2-to-NO converter that meets the verification in
Sec.  1065.378. Configure the converter with a bypass line if it is
needed to facilitate this verification.
    (d) Humidity effects. You must maintain all CLD temperatures to
prevent aqueous condensation. If you remove humidity from a sample
upstream of a CLD, use one of the following configurations:
* * * * *

0
70. Section 1065.280 is revised to read as follows:

Sec.  1065.280  Paramagnetic and magnetopneumatic O2 detection
analyzers.

    (a) Application. You may use a paramagnetic detection (PMD) or
magnetopneumatic detection (MPD) analyzer to measure O2
concentration in raw or diluted exhaust for batch or continuous
sampling. You may use O2 measurements with intake air or
fuel flow measurements to calculate exhaust flow rate according to
Sec.  1065.650.
    (b) Component requirements. We recommend that you use a PMD or MPD
analyzer that meets the specifications in Table 1 of Sec.  1065.205.
Note that it must meet the linearity verification in Sec.  1065.307.
You may use a PMD or MPD that has compensation algorithms that are
functions of other gaseous measurements and the engine's known or
assumed fuel properties. The target value for any compensation
algorithm is 0.0% (that is, no bias high and no bias low), regardless
of the uncompensated signal's bias.

0
71. Section 1065.290 is amended by revising paragraph (c)(1) to read as
follows:

Sec.  1065.290  PM gravimetric balance.

* * * * *
    (c) * * *
    (1) Use a pan that centers the PM sample media (such as a filter)
on the weighing pan. For example, use a pan in the shape of a cross
that has upswept tips that center the PM sample media on the pan.
* * * * *

Subpart D--[Amended]

0
72. Section 1065.303 is revised to read as follows:

Sec.  1065.303  Summary of required calibration and verifications.

    The following table summarizes the required and recommended
calibrations and verifications described in this subpart and indicates
when these have to be performed:

    Table 1 of Sec.   1065.303.--Summary of Required Calibration and
                              Verifications
------------------------------------------------------------------------
    Type of calibration or
         verification                     Minimum frequency a
------------------------------------------------------------------------
Sec.   1065.305: Accuracy,     Accuracy: Not required, but recommended
 repeatability and noise.       for initial installation.
                               Repeatability: Not required, but
                                recommended for initial installation.
                               Noise: Not required, but recommended for
                                initial installation.

Sec.   1065.307: Linearity...  Speed: Upon initial installation, within
                                370 days before testing and after major
                                maintenance.
                               Torque: Upon initial installation, within
                                370 days before testing and after major
                                maintenance.
                               Electrical power: Upon initial
                                installation, within 370 days before
                                testing and after major maintenance.
                               Clean gas and diluted exhaust flows: Upon
                                initial installation, within 370 days
                                before testing and after major
                                maintenance, unless flow is verified by
                                propane check or by carbon or oxygen
                                balance.
                               Raw exhaust flow: Upon initial
                                installation, within 185 days before
                                testing and after major maintenance,
                                unless flow is verified by propane check
                                or by carbon or oxygen balance.
                               Gas analyzers: Upon initial installation,
                                within 35 days before testing and after
                                major maintenance.
                               PM balance: Upon initial installation,
                                within 370 days before testing and after
                                major maintenance.
                               Stand-alone pressure and temperature:
                                Upon initial installation, within 370
                                days before testing and after major
                                maintenance.
Sec.   1065.308: Continuous    Upon initial installation, after system
 analyzer system response and   reconfiguration, and after major
 recording.                     maintenance.
Sec.   1065.309: Continuous    Upon initial installation, after system
 analyzer uniform response.     reconfiguration, and after major
                                maintenance.
Sec.   1065.310: Torque......  Upon initial installation and after major
                                maintenance.
Sec.   1065.315: Pressure,     Upon initial installation and after major
 temperature, dewpoint.         maintenance.
Sec.   1065.320: Fuel flow...  Upon initial installation and after major
                                maintenance.
Sec.   1065.325: Intake flow.  Upon initial installation and after major
                                maintenance.
Sec.   1065.330: Exhaust flow  Upon initial installation and after major
                                maintenance.
Sec.   1065.340: Diluted       Upon initial installation and after major
 exhaust flow (CVS).            maintenance.
Sec.   1065.341: CVS and       Upon initial installation, within 35 days
 batch sampler verification b.  before testing, and after major
                                maintenance.
Sec.   1065.345: Vacuum leak.  Before each laboratory test according to
                                subpart F of this part and before each
                                field test according to subpart J of
                                this part.
Sec.   1065.350: CO2 NDIR H2O  Upon initial installation and after major
 interference.                  maintenance.
Sec.   1065.355: CO NDIR CO2   Upon initial installation and after major
 and H2O interference.          maintenance.
Sec.   1065.360: FID           Calibrate all FID analyzers: Upon initial
 calibration THC FID            installation and after major
 optimization, and THC FID      maintenance.
 verification.                 Optimize and determine CH4 response for
                                THC FID analyzers: upon initial
                                installation and after major
                                maintenance.
                               Verify CH4 response for THC FID
                                analyzers: Upon initial installation,
                                within 185 days before testing, and
                                after major maintenance.
Sec.   1065.362: Raw exhaust   For all FID analyzers: Upon initial
 FID O2 interference.           installation, and after major
                                maintenance.
                               For THC FID analyzers: Upon initial
                                installation, after major maintenance,
                                and after FID optimization according to
                                Sec.   1065.360.
Sec.   1065.365: Nonmethane    Upon initial installation, within 185
 cutter penetration.            days before testing, and after major
                                maintenance.
Sec.   1065.370: CLD CO2 and   Upon initial installation and after major
 H2O quench.                    maintenance.
Sec.   1065.372: NDUV HC and   Upon initial installation and after major
 H2O interference.              maintenance.
Sec.   1065.376: Chiller       Upon initial installation and after major
 NO\2\ penetration.             maintenance.
Sec.   1065.378: NO\2\-to-NO   Upon initial installation, within 35 days
 converter conversion.          before testing, and after major
                                maintenance.
Sec.   1065.390: PM balance    Independent verification: Upon initial
 and weighing.                  installation, within 370 days before
                                testing, and after major maintenance.
                               Zero, span, and reference sample
                                verifications: Within 12 hours of
                                weighing, and after major maintenance.
Sec.   1065.395: Inertial PM   Independent verification: Upon initial
 balance and weighing.          installation, within 370 days before
                                testing, and after major maintenance.
                               Other verifications: Upon initial
                                installation and after major
                                maintenance.
------------------------------------------------------------------------
a Perform calibrations and verifications more frequently, according to
  measurement system manufacturer instructions and good engineering
  judgment.
b The CVS verification described in Sec.   1065.341 is not required for
  systems that agree within  2% based on a chemical balance
  of carbon or oxygen of the intake air, fuel, and diluted exhaust.

0
73. Section 1065.305 is amended by revising paragraphs (d)(4), (d)(8),
and (d)(9)(iii) to read as follows:

Sec.  1065.305  Verifications for accuracy, repeatability, and noise.

* * * * *
    (d) * * *
    (4) Use the instrument to quantify a NIST-traceable reference
quantity, yref. For gas analyzers the reference gas must
meet the specifications of Sec.  1065.750. Select a reference quantity
near the mean value expected during testing. For all gas analyzers, use
a quantity near the flow-weighted mean concentration expected at the
standard or expected during testing, whichever is greater. For noise
verification, use the same zero gas from paragraph (e) of this section
as the reference quantity. In all cases, allow time for the instrument
to stabilize while it measures the reference quantity. Stabilization
time may include time to purge an instrument and time to account for
its response.
* * * * *
    (8) Repeat the steps specified in paragraphs (d)(2) through (7) of
this section until you have ten arithmetic means (y\1\, y\2\,
yi,...y10), ten standard deviations, ([sigma]\1\,
[sigma]\2\, [sigma]i,...[sigma]10), and ten
errors ([egr]\1\, [egr]\2\, [egr]i,...[egr]10).
    (9) * * *
    (iii) Noise. Noise is two times the root-mean-square of the ten
standard

deviations (that is, noise = 2[middot]rms[sigma]) when the
reference signal is a zero-quantity signal. Refer to the example of a
root-mean-square calculation in Sec.  1065.602. We recommend that
instrument noise be within the specifications in Table 1 of Sec.
1065.205.
* * * * *

0
74. Section 1065.307 is amended by revising paragraphs (b), (c)(6),
(c)(13), and Table 1 and adding paragraphs (d)(8) and (e) before the
newly revised table to read as follows:

Sec.  1065.307  Linearity verification.

* * * * *
    (b) Performance requirements. If a measurement system does not meet
the applicable linearity criteria in Table 1 of this section, correct
the deficiency by re-calibrating, servicing, or replacing components as
needed. Repeat the linearity verification after correcting the
deficiency to ensure that the measurement system meets the linearity
criteria. Before you may use a measurement system that does not meet
linearity criteria, you must demonstrate to us that the deficiency does
not adversely affect your ability to demonstrate compliance with the
applicable standards.
    (c) * * *
    (6) For all measured quantities, use instrument manufacturer
recommendations and good engineering judgment to select reference
values, yrefi, that cover a range of values that you expect
would prevent extrapolation beyond these values during emission
testing. We recommend selecting a zero reference signal as one of the
reference values of the linearity verification. For stand-alone
pressure and temperature linearity verifications, we recommend at least
three reference values. For all other linearity verifications select at
least ten reference values.
* * * * *
    (13) Use the arithmetic means, yi, and reference values,
yrefi, to calculate least-squares linear regression
parameters and statistical values to compare to the minimum performance
criteria specified in Table 1 of this section. Use the calculations
described in Sec.  1065.602. Using good engineering judgment, you may
weight the results of individual data pairs (i.e., (yrefi,
yi)), in the linear regression calculations.
    (d) * * *
    (8) Temperature. You may perform the linearity verification for
temperature measurement systems with thermocouples, RTDs, and
thermistors by removing the sensor from the system and using a
simulator in its place. Use a NIST-traceable simulator that is
independently calibrated and, as appropriate, cold-junction
compensated. The simulator uncertainty scaled to temperature must be
less than 0.5% of Tmax. If you use this option, you must use
sensors that the supplier states are accurate to better than 0.5% of
Tmax compared with their standard calibration curve.
    (e) Measurement systems that require linearity verification. Table
1 of this section indicates measurement systems that require linearity
verifications, subject to the following provisions:
    (1) Perform a linearity verification more frequently based on the
instrument manufacturer's recommendation or good engineering judgment.
    (2) The expression ``min'' refers to the minimum reference value
used during the linearity verification. Note that this value may be
zero or a negative value depending on the signal.
    (3) The expression ``max'' generally refers to the maximum
reference value used during the linearity verification. For example for
gas dividers, xmax is the undivided, undiluted, span gas
concentration. The following are special cases where ``max'' refers to
a different value:
    (i) For linearity verification with a PM balance, mmax
refers to the typical mass of a PM filter.
    (ii) For linearity verification of torque, Tmax refers
to the manufacturer's specified engine torque peak value of the lowest
torque engine to be tested.
    (4) The specified ranges are inclusive. For example, a specified
range of 0.98-1.02 for a\1\ means 0.98<=a1<=1.02.
    (5) These linearity verifications are optional for systems that
pass the flow-rate verification for diluted exhaust as described in
Sec.  1065.341 (the propane check) or for systems that agree within
2% based on a chemical balance of carbon or oxygen of the
intake air, fuel, and exhaust.
    (6) You must meet the a\1\ criteria for these quantities only if
the absolute value of the quantity is required, as opposed to a signal
that is only linearly proportional to the actual value.
    (7) The following provisions apply for stand-alone temperature
measurements:
    (i) The following temperature linearity checks are required:
    (A) Air intake.
    (B) Aftertreatment bed(s), for engines tested with aftertreatment
devices subject to cold-start testing.
    (C) Dilution air for PM sampling, including CVS, double-dilution,
and partial-flow systems.
    (D) PM sample, if applicable.
    (E) Chiller sample, for gaseous sampling systems that use chillers
to dry samples.
    (ii) The following temperature linearity checks are required only
if specified by the engine manufacturer:
    (A) Fuel inlet.
    (B) Air outlet to the test cell's charge air cooler air outlet, for
engines tested with a laboratory heat exchanger that simulates an
installed charge air cooler.
    (C) Coolant inlet to the test cell's charge air cooler, for engines
tested with a laboratory heat exchanger that simulates an installed
charge air cooler.
    (D) Oil in the sump/pan.
    (E) Coolant before the thermostat, for liquid-cooled engines.
    (8) The following provisions apply for stand-alone pressure
measurements:
    (i) The following pressure linearity checks are required:
    (A) Air intake restriction.
    (B) Exhaust back pressure.
    (C) Barometer.
    (D) CVS inlet gage pressure.
    (E) Chiller sample, for gaseous sampling systems that use chillers
to dry samples.
    (ii) The following pressure linearity checks are required only if
specified by the engine manufacturer:
    (A) The test cell's charge air cooler and interconnecting pipe
pressure drop, for turbo-charged engines tested with a laboratory heat
exchanger that simulates an installed charge air cooler.
    (B) Fuel outlet.

                                  Table 1 of Sec.   1065.307.--Measurement Systems That Require Linearity Verifications
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Linearity criteria
                                                   Minimum verification  -------------------------------------------------------------------------------
       Measurement system           Quantity            frequency           [verbarlm]xmin(a\1\-
                                                                              1)+a0 [verbarlm]         a\1\               SEE                  r\2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Engine speed...................  [fnof]n.......  Within 370 days before   <=0.05 % [fnof]nmax....    0.98-1.02  <=2 % [middot]           >=0.990
                                                  testing.                                                       [fnof]nmax.
Engine torque..................  T.............  Within 370 days before   <=1 % [middot] Tmax....    0.98-1.02  <=2 % [middot] Tmax....  >=0.990
                                                  testing.
Electrical work................  W.............  Within 370 days before   <=1 % [middot] Tmax....    0.98-1.02  <=2 % [middot] Tmax....  >=0.990
                                                  testing.
Fuel flow rate.................  m.............  Within 370 days before   <=1 % [middot] mmax....    0.98-1.02  <=2 % [middot] mmax....  >=0.990
                                                  testing d.

Intake-air flow rate...........  n.............  Within 370 days before   <=1 % [middot] nmax....    0.98-1.02  <=2 % [middot] nmax....  >=0.990
                                                  testing.
Dilution air flow rate.........  n.............  Within 370 days before   <=1 % [middot] nmax....    0.98-1.02  <=2 % [middot] nmax....  >=0.990
                                                  testing.
Diluted exhaust flow rate......  n.............  Within 370 days before   <=1 % [middot] nmax....    0.98-1.02  <=2 % [middot] nmax....  >=0.990
                                                  testing.
Raw exhaust flow rate..........  n.............  Within 185 days before   <=1 % [middot] nmax....    0.98-1.02  <=2 % [middot] nmax....  >=0.990
                                                  testing.
Batch sampler flow rates.......  n.............  Within 370 days before   <=1 % [middot] nmax....    0.98-1.02  <=2 % [middot] nmax....  >=0.990
                                                  testing.
Gas dividers...................  x/xspan.......  Within 370 days before   <=0.5 % [middot] xmax..    0.98-1.02  <=2 % [middot] xmax....  >=0.990
                                                  testing.
Gas analyzers for laboratory     x.............  Within 35 days before    <=0.5 % [middot] xmax..    0.99-1.01  <=1 % [middot] xmax....  >=0.998
 testing.                                         testing.
Gas analyzers for field testing  x.............  Within 35 days before    <=1 % [middot] xmax....    0.99-1.01  <=1 % [middot] xmax....  >=0.998
                                                  testing.
PM balance.....................  m.............  Within 370 days before   <=1 % [middot] mmax....    0.99-1.01  <=1 % [middot] mmax....  >=0.998
                                                  testing.
Stand-alone pressures..........  p.............  Within 370 days before   <=1 % [middot] pmax....    0.99-1.01  <=1 % [middot] pmax....  >=0.998
                                                  testing.
Analog-to-digital conversion of  T.............  Within 370 days before   <=1 % [middot] Tmax....    0.99-1.01  <=1 % [middot] Tmax....  >=0.998
 stand-alone temperature                          testing.
 signals.
--------------------------------------------------------------------------------------------------------------------------------------------------------

0
75. Section 1065.308 is revised to read as follows:

Sec.  1065.308  Continuous gas analyzer system-response and updating-
recording verification--general.

    This section describes a general verification procedure for
continuous gas analyzer system response and update recording. See Sec.
1065.309 for verification procedures that apply for systems or
components involving H2O correction.
    (a) Scope and frequency. Perform this verification after installing
or replacing a gas analyzer that you use for continuous sampling. Also
perform this verification if you reconfigure your system in a way that
would change system response. For example, perform this verification if
you add a significant volume to the transfer lines by increasing their
length or adding a filter; or if you reduce the frequency at which you
sample and record gas-analyzer concentrations. You do not have to
perform this verification for gas analyzer systems used only for
discrete-mode testing.
    (b) Measurement principles. This test verifies that the updating
and recording frequencies match the overall system response to a rapid
change in the value of concentrations at the sample probe. Gas analyzer
systems must be optimized such that their overall response to a rapid
change in concentration is updated and recorded at an appropriate
frequency to prevent loss of information. This test also verifies that
continuous gas analyzer systems meet a minimum response time.
    (c) System requirements. To demonstrate acceptable updating and
recording with respect to the system's overall response, use good
engineering judgment to select one of the following criteria that your
system must meet:
    (1) The product of the mean rise time and the frequency at which
the system records an updated concentration must be at least 5, and the
product of the mean fall time and the frequency at which the system
records an updated concentration must be at least 5. This criterion
makes no assumption regarding the frequency content of changes in
emission concentrations during emission testing; therefore, it is valid
for any testing. In any case the mean rise time and the mean fall time
must be no more than 10 seconds.
    (2) The frequency at which the system records an updated
concentration must be at least 5 Hz. This criterion assumes that the
frequency content of significant changes in emission concentrations
during emission testing do not exceed 1 Hz. In any case the mean rise
time and the mean fall time must be no more than 10 seconds.
    (3) You may use other criteria if we approve the criteria in
advance.
    (4) You may meet the overall PEMS verification in Sec.  1065.920
instead of the verification in this section for field testing with
PEMS.
    (d) Procedure. Use the following procedure to verify the response
of a continuous gas analyzer system:
    (1) Instrument setup. Follow the analyzer system manufacturer's
start-up and operating instructions. Adjust the system as needed to
optimize performance.
    (2) Equipment setup. We recommend using minimal lengths of gas
transfer lines between all connections and fast-acting three-way valves
(2 inlets, 1 outlet) to control the flow of zero and blended span gases
to the analyzers. You may use a gas mixing or blending device to
equally blend an NO-CO-CO2-C3H8-
CH4, balance N2 span gas with a span gas of
NO2, balance purified synthetic air. Standard binary span
gases may also be used, where applicable, in place of blended NO-CO-
CO2-C3H8-CH4, balance
N2 span gas, but separate response tests must then be run
for each analyzer. In designing your experimental setup, avoid pressure
pulsations due to stopping the flow through the gas-blending device.
Note that you may omit any of these gas constituents if they are not
relevant to your analyzers for this verification.
    (3) Data collection. (i) Start the flow of zero gas.
    (ii) Allow for stabilization, accounting for transport delays and
the slowest instrument's full response.
    (iii) Start recording data at the frequency used during emission
testing. Each recorded value must be a unique updated concentration
measured by the analyzer; you may not use interpolation to increase the
number of recorded values.
    (iv) Switch the flow to allow the blended span gases to flow to the
analyzer.
    (v) Allow for transport delays and the slowest instrument's full
response.
    (vi) Repeat the steps in paragraphs (d)(3)(i) through (v) of this
section to record seven full cycles, ending with zero gas flowing to
the analyzers.
    (vii) Stop recording.
    (e) Performance evaluation. (1) If you chose to demonstrate
compliance with paragraph (c)(1) of this section, use the data from
paragraph (d)(3) of this section to calculate the mean rise time,
t10-90, and mean fall time, t10-90, for each of
the analyzers. Multiply these times (in seconds) by their respective
recording frequencies in Hertz (1/second). The value for each result
must be at least 5. If the value is less than 5, increase the recording
frequency or adjust the flows or design of the sampling system to
increase the rise time and fall time as needed. You may

also configure digital filters to increase rise and fall times. The
mean rise time and mean fall time must be no greater than 10 seconds.
    (2) If a measurement system fails the criterion in paragraph (e)(1)
of this section, ensure that signals from the system are updated and
recorded at a frequency of at least 5 Hz. In any case, the mean rise
time and mean fall time must be no greater than 10 seconds.
    (3) If a measurement system fails the criteria in paragraphs (e)(1)
and (2) of this section, you may use the continuous analyzer system
only if the deficiency does not adversely affect your ability to show
compliance with the applicable standards.

0
76. Section 1065.309 is revised to read as follows:

Sec.  1065.309  Continuous gas analyzer system-response and updating-
recording verification--with humidified-response verification.

    This section describes a verification procedure for continuous gas
analyzer system response and update recording for systems or components
involving H2O correction. See Sec.  1065.308 for
verification procedures that apply for systems not involving
humidification.
    (a) Scope and frequency. Perform this verification to determine a
continuous gas analyzer's response, where one analyzer's response is
compensated by another's to quantify a gaseous emission. For this check
we consider water vapor a gaseous constituent. You do not have to
perform this verification for batch gas analyzer systems or for
continuous analyzer systems that are only used for discrete-mode
testing. Perform this verification after initial installation (i.e.
test cell commissioning). The verification in this section is required
for initial installation of systems or components involving
H2O correction. For later verifications, you may use the
procedures specified in Sec.  1065.308, as long as your system includes
no replacement components involving H2O correction that have
never been verified using the procedures in this section.
    (b) Measurement principles. This procedure verifies the time-
alignment and uniform response of continuously combined gas
measurements. For this procedure, ensure that all compensation
algorithms and humidity corrections are turned on.
    (c) System requirements. Demonstrate that continuously combined
concentration measurements have a uniform rise and fall during a system
response to a rapid change in multiple gas concentrations. You must
meet one of the following criteria:
    (1) The product of the mean rise time and the frequency at which
the system records an updated concentration must be at least 5, and the
product of the mean fall time and the frequency at which the system
records an updated concentration must be at least 5. This criterion
makes no assumption regarding the frequency content of changes in
emission concentrations during emission testing; therefore, it is valid
for any testing. In no case may the mean rise time or the mean fall
time be more than 10 seconds.
    (2) The frequency at which the system records an updated
concentration must be at least 5 Hz. This criterion assumes that the
frequency content of significant changes in emission concentrations
during emission testing do not exceed 1 Hz. In no case may the mean
rise time or the mean fall time be more than 10 seconds.
    (3) You may use other criteria if we approve them in advance.
    (4) You may meet the overall PEMS verification in Sec.  1065.920
instead of the verification in this section for field testing with
PEMS.
    (d) Procedure. Use the following procedure to verify the response
of a continuous gas analyzer system:
    (1) Instrument setup. Follow the analyzer system manufacturer's
start-up and operating instructions. Adjust the system as needed to
optimize performance.
    (2) Equipment setup. We recommend using minimal lengths of gas
transfer lines between all connections and fast-acting three-way valves
(2 inlets, 1 outlet) to control the flow of zero and blended span gases
to the analyzers. You may use a gas blending or mixing device to
equally blend a span gas of NO-CO-CO2-
C3H8-CH4, balance N2, with
a span gas of NO2, balance purified synthetic air. Standard
binary span gases may be used, where applicable, in place of blended
NO-CO-CO2-C3H8-CH4, balance
N2 span gas, but separate response tests must then be run
for each analyzer. In designing your experimental setup, avoid pressure
pulsations due to stopping the flow through the gas blending device.
Span gases must be humidified before entering the analyzer; however,
you may not humidify NO2 span gas by passing it through a
sealed humidification vessel that contains water. We recommend
humidifying your NO-CO-CO2-C3H8-
CH4, balance N2 blended gas by flowing the gas
mixture through a sealed vessel that humidifies the gas by bubbling it
through distilled water and then mixing the gas with dry NO2
gas, balance purified synthetic air. If your system does not use a
sample dryer to remove water from the sample gas, you must humidify
your span gas by flowing the gas mixture through a sealed vessel that
humidifies the gas to the highest sample dewpoint that you estimate
during emission sampling by bubbling it through distilled water. If
your system uses a sample dryer during testing that has passed the
sample dryer verification check in Sec.  1065.342, you may introduce
the humidified gas mixture downstream of the sample dryer by bubbling
it through distilled water in a sealed vessel at (25  10)
[deg]C, or a temperature greater than the dewpoint determined in Sec.
1065.145(d)(2). In all cases, maintain the humidified gas temperature
downstream of the vessel at least 5 [deg]C above its local dewpoint in
the line. We recommend that you heat all gas transfer lines and valves
located downstream of the vessel as needed to avoid condensation. Note
that you may omit any of these gas constituents if they are not
relevant to your analyzers for this verification. If any of your gas
constituents are not susceptible to water compensation, you may perform
the response check for these analyzers without humidification.
    (3) Data collection. (i) Start the flow of zero gas.
    (ii) Allow for stabilization, accounting for transport delays and
the slowest instrument's full response.
    (iii) Start recording data at the frequency used during emission
testing. Each recorded value must be a unique updated concentration
measured by the analyzer; you may not use interpolation to increase the
number of recorded values.
    (iv) Switch the flow to allow the blended span gases to flow to the
analyzers.
    (v) Allow for transport delays and the slowest instrument's full
response.
    (vi) Repeat the steps in paragraphs (d)(3)(i) through (v) of this
section to record seven full cycles, ending with zero gas flowing to
the analyzers.
    (vii) Stop recording.
    (e) Performance evaluations. (1) If you chose to demonstrate
compliance with paragraph (c)(1) of this section, use the data from
paragraph (d)(3) of this section to calculate the mean rise time,
t10-90, and mean fall time, tS90-10, for each of
the analyzers. Multiply these times (in seconds) by their respective
recording frequencies in Hz (1/second). The value for each result must
be at least 5. If the value is less than 5, increase the recording
frequency or adjust the flows or design of the sampling system to
increase the rise time and fall time as needed. You may also configure
digital filters to increase rise and fall times. In no case may the

mean rise time or mean fall time be greater than 10 seconds.
    (2) If a measurement system fails the criterion in paragraph (e)(1)
of this section, ensure that signals from the system are updated and
recorded at a frequency of at least 5 Hz. In no case may the mean rise
time or mean fall time be greater than 10 seconds.
    (3) If a measurement system fails the criteria in paragraphs (e)(1)
and (2) of this section, you may use the continuous analyzer system
only if the deficiency does not adversely affect your ability to show
compliance with the applicable standards.

0
77. Section 1065.310 is amended by revising paragraph (d) to read as
follows:

Sec.  1065.310  Torque calibration.

* * * * *
    (d) Strain gage or proving ring calibration. This technique applies
force either by hanging weights on a lever arm (these weights and their
lever arm length are not used as part of the reference torque
determination) or by operating the dynamometer at different torques.
Apply at least six force combinations for each applicable torque-
measuring range, spacing the force quantities about equally over the
range. Oscillate or rotate the dynamometer during calibration to reduce
frictional static hysteresis. In this case, the reference torque is
determined by multiplying the force output from the reference meter
(such as a strain gage or proving ring) by its effective lever-arm
length, which you measure from the point where the force measurement is
made to the dynamometer's rotational axis. Make sure you measure this
length perpendicular to the reference meter's measurement axis and
perpendicular to the dynamometer's rotational axis.

0
78. Section 1065.315 is amended by revising paragraph (a)(2) to read as
follows:

Sec.  1065.315  Pressure, temperature, and dewpoint calibration.

    (a) * * *
    (2) Temperature. We recommend digital dry-block or stirred-liquid
temperature calibrators, with data logging capabilities to minimize
transcription errors. We recommend using calibration reference
quantities that are NIST-traceable within 0.5% uncertainty. You may
perform the linearity verification for temperature measurement systems
with thermocouples, RTDs, and thermistors by removing the sensor from
the system and using a simulator in its place. Use a NIST-traceable
simulator that is independently calibrated and, as appropriate, cold-
junction compensated. The simulator uncertainty scaled to temperature
must be less than 0.5% of Tmax. If you use this option, you
must use sensors that the supplier states are accurate to better than
0.5% of Tmax compared with their standard calibration curve.
* * * * *

0
79. Section 1065.340 is amended by revising paragraphs (f)(5),
(f)(6)(ii), (f)(7), (f)(9), (f)(10), (g)(6)(i), and Figure 1 to read as
follows:

Sec.  1065.340  Diluted exhaust flow (CVS) calibration.

* * * * *
    (f) * * *
    (5) Set the variable restrictor to its wide-open position. Instead
of a variable restrictor, you may alternately vary the pressure
downstream of the CFV by varying blower speed or by introducing a
controlled leak. Note that some blowers have limitations on nonloaded
conditions.
    (6) * * *
    (ii) The mean dewpoint of the calibration air, Tdew. See
Sec.  1065.640 for permissible assumptions during emission
measurements.
* * * * *
    (7) Incrementally close the restrictor valve or decrease the
downstream pressure to decrease the differential pressure across the
CFV,[Delta]PCFV.
* * * * *
    (9) Determine Cd and the lowest allowable pressure
ratio, r, according to Sec.  1065.640.
    (10) Use Cd to determine CFV flow during an emission test. Do not
use the CFV below the lowest allowed r, as determined in Sec.
1065.640.
* * * * *
    (g) * * *
    (6) * * *
    (i) The mean flow rate of the reference flow meter,nref.
This may include several measurements of different quantities, such as
reference meter pressures and temperatures, for calculating
nref.
* * * * *
BILLING CODE 6560-50-P

[GRAPHIC] [TIFF OMITTED] TR06MY08.020

BILLING CODE 6560-50-C
0
80. Section 1065.341 is amended by revising paragraphs (d) introductory
text, (d)(7), and (g) introductory text to read as follows:

Sec.  1065.341  CVS and batch sampler verification (propane check).

* * * * *
    (d) If you performed the vacuum-side leak verification of the HC
sampling system as described in paragraph (c)(8) of this section, you
may use the HC contamination procedure in Sec.  1065.520(g) to verify
HC contamination. Otherwise, zero, span, and verify contamination of
the HC sampling system, as follows:
* * * * *
    (7) When the overflow HC concentration does not exceed 2 [mu]mol/
mol, record this value as xTHCinit and use it to correct for
HC contamination as described in Sec.  1065.660.
* * * * *

    (g) You may repeat the propane check to verify a batch sampler,
such as a PM secondary dilution system.
* * * * *
0
81. A new Sec.  1065.342 is added to read as follows:

Sec.  1065.342  Sample dryer verification.

    (a) Scope and frequency. If you use a sample dryer as allowed in
Sec.  1065.145(d)(2) to remove water from the sample gas, verify the
performance upon installation, after major maintenance, for thermal
chiller. For osmotic membrane dryers, verify the performance upon
installation, after major maintenance, and within 35 days of testing.
    (b) Measurement principles. Water can inhibit an analyzer's ability
to properly measure the exhaust component of interest and thus is
sometimes removed before the sample gas reaches the analyzer. For
example water can negatively interfere with a CLD's NOX
response through collisional quenching and can positively interfere
with an NDIR analyzer by causing a response similar to CO.
    (c) System requirements. The sample dryer must meet the
specifications as determined in Sec.  1065.145(d)(2) for dewpoint,
Tdew, and absolute pressure, ptotal, downstream
of the osmotic-membrane dryer or thermal chiller.
    (d) Sample dryer verification procedure. Use the following method
to determine sample dryer performance, or use good engineering judgment
to develop a different protocol:
    (1) Use PTFE or stainless steel tubing to make necessary
connections.
    (2) Humidify N\2\ or purified air by bubbling it through distilled
water in a sealed vessel that humidifies the gas to the highest sample
dewpoint that you estimate during emission sampling.
    (3) Introduce the humidified gas upstream of the sample dryer.
    (4) Downstream of the vessel, maintain the humidified gas
temperature at least 5 [deg]C above its dewpoint.
    (5) Measure the humidified gas dewpoint, Tdew, and
pressure, ptotal, as close as possible to the inlet of the
sample dryer to verify the dewpoint is the highest that you estimated
during emission sampling.
    (6) Measure the humidified gas dewpoint, Tdew, and
pressure, ptotal, as close as possible to the outlet of the
sample dryer.
    (7) The sample dryer meets the verification if the results of
paragraph (d)(6) of this section are less than the dew point
corresponding to the sample dryer specifications as determined in Sec.
1065.145(d)(2) plus 2 [deg]C or if the mole fraction from (d)(6) is
less than the corresponding sample dryer specifications plus 0.002 mol/
mol.
    (e) Alternate sample dryer verification procedure. The following
method may be used in place of the sample dryer verification procedure
in (d) of this section. If you use a humidity sensor for continuous
monitoring of dewpoint at the sample dryer outlet you may skip the
performance check in Sec.  1065.342(d), but you must make sure that the
dryer outlet humidity is below the minimum values used for quench,
interference, and compensation checks.

0
82. Section 1065.345 is revised to read as follows:

Sec.  1065.345  Vacuum-side leak verification.

    (a) Scope and frequency. Verify that there are no significant
vacuum-side leaks using one of the leak tests described in this section
upon initial sampling system installation, after maintenance such as
pre-filter changes, and within eight hours before each duty-cycle
sequence. This verification does not apply to any full-flow portion of
a CVS dilution system.
    (b) Measurement principles. A leak may be detected either by
measuring a small amount of flow when there should be zero flow, or by
detecting the dilution of a known concentration of span gas when it
flows through the vacuum side of a sampling system.
    (c) Low-flow leak test. Test a sampling system for low-flow leaks
as follows:
    (1) Seal the probe end of the system by taking one of the following
steps:
    (i) Cap or plug the end of the sample probe.
    (ii) Disconnect the transfer line at the probe and cap or plug the
transfer line.
    (iii) Close a leak-tight valve located in the sample transfer line
within 92 cm of the probe.
    (2) Operate all vacuum pumps. After stabilizing, verify that the
flow through the vacuum-side of the sampling system is less than 0.5%
of the system's normal in-use flow rate. You may estimate typical
analyzer and bypass flows as an approximation of the system's normal
in-use flow rate.
    (d) Dilution-of-span-gas leak test. You may use any gas analyzer
for this test. If you use a FID for this test, correct for any HC
contamination in the sampling system according to Sec.  1065.660. To
avoid misleading results from this test, we recommend using only
analyzers that have a repeatability of 0.5% or better at the span gas
concentration used for this test. Perform a vacuum-side leak test as
follows:
    (1) Prepare a gas analyzer as you would for emission testing.
    (2) Supply span gas to the analyzer port and verify that it
measures the span gas concentration within its expected measurement
accuracy and repeatability.
    (3) Route overflow span gas to one of the following locations in
the sampling system:
    (i) The end of the sample probe.
    (ii) Disconnect the transfer line at the probe connection, and
overflow the span gas at the open end of the transfer line.
    (iii) A three-way valve installed in-line between a probe and its
transfer line, such as a system overflow zero and span port.
    (4) Verify that the measured overflow span gas concentration is
within  0.5% of the span gas concentration. A measured
value lower than expected indicates a leak, but a value higher than
expected may indicate a problem with the span gas or the analyzer
itself. A measured value higher than expected does not indicate a leak.
    (e) Vacuum-decay leak test. To perform this test you must apply a
vacuum to the vacuum-side volume of your sampling system and then
observe the leak rate of your system as a decay in the applied vacuum.
To perform this test you must know the vacuum-side volume of your
sampling system to within  10% of its true volume. For this
test you must also use measurement instruments that meet the
specifications of subpart C of this part and of this subpart D. Perform
a vacuum-decay leak test as follows:
    (1) Seal the probe end of the system as close to the probe opening
as possible by taking one of the following steps:
    (i) Cap or plug the end of the sample probe.
    (ii) Disconnect the transfer line at the probe and cap or plug the
transfer line.
    (iii) Close a leak-tight valve in-line between a probe and transfer
line.
    (2) Operate all vacuum pumps. Draw a vacuum that is representative
of normal operating conditions. In the case of sample bags, we
recommend that you repeat your normal sample bag pump-down procedure
twice to minimize any trapped volumes.
    (3) Turn off the sample pumps and seal the system. Measure and
record the absolute pressure of the trapped gas and optionally the
system absolute temperature. Wait long enough for any transients to
settle and long enough for a leak at 0.5% to have caused a pressure
change of at least 10 times the resolution of the pressure transducer,
then again record the pressure and optionally temperature.
    (4) Calculate the leak flow rate based on an assumed value of zero
for

pumped-down bag volumes and based on known values for the sample system
volume, the initial and final pressures, optional temperatures, and
elapsed time. Using the calculations specified in 1065.644, verify that
the vacuum-decay leak flow rate is less than 0.5% of the system's
normal in-use flow rate.

0
83. Section 1065.350 is amended by revising paragraphs (c) and (d) to
read as follows:

Sec.  1065.350  H2O interference verification for CO2 NDIR analyzers.

* * * * *
    (c) System requirements. A CO2 NDIR analyzer must have
an H2O interference that is within (0.0 0.4)
mmol/mol, though we strongly recommend a lower interference that is
within (0.0 0.2) mmol/mol.
    (d) Procedure. Perform the interference verification as follows:
    (1) Start, operate, zero, and span the CO2 NDIR analyzer
as you would before an emission test.
    (2) Create a humidified test gas by bubbling zero air that meets
the specifications in Sec.  1065.750 through distilled water in a
sealed vessel. If the sample is not passed through a dryer, control the
vessel temperature to generate an H2O level at least as high
as the maximum expected during testing. If the sample is passed through
a dryer during testing, control the vessel temperature to generate an
H2O level at least as high as the level determined in Sec.
1065.145(d)(2).
    (3) Introduce the humidified test gas into the sample system. You
may introduce it downstream of any sample dryer, if one is used during
testing.
    (4) Measure the humidified test gas dewpoint, Tdew, and
pressure, ptotal, as close as possible to the inlet of the
analyzer.
    (5) Downstream of the vessel, maintain the humidified test gas
temperature at least 5 [deg]C above its dewpoint.
    (6) Allow time for the analyzer response to stabilize.
Stabilization time may include time to purge the transfer line and to
account for analyzer response.
    (7) While the analyzer measures the sample's concentration, record
30 seconds of sampled data. Calculate the arithmetic mean of this data.
The analyzer meets the interference verification if this value is
within (0 0.4) mmol/mol.
* * * * *

0
84. Section 1065.355 is amended by revising paragraph (d) to read as
follows:

Sec.  1065.355  H2O and CO2 interference verification for CO NDIR
analyzers.

* * * * *
    (d) Procedure. Perform the interference verification as follows:
    (1) Start, operate, zero, and span the CO NDIR analyzer as you
would before an emission test.
    (2) Create a humidified CO2 test gas by bubbling a
CO2 span gas through distilled water in a sealed vessel. If
the sample is not passed through a dryer, control the vessel
temperature to generate an H2O level at least as high as the
maximum expected during testing. If the sample is passed through a
dryer during testing, control the vessel temperature to generate an
H2O level at least as high as the level determined in Sec.
1065.145(d)(2). Use a CO2 span gas concentration at least as
high as the maximum expected during testing.
    (3) Introduce the humidified CO2 test gas into the
sample system. You may introduce it downstream of any sample dryer, if
one is used during testing.
    (4) Measure the humidified CO2 test gas dewpoint,
Tdew, and pressure, ptotal, as close as possible
to the inlet of the analyzer.
    (5) Downstream of the vessel, maintain the humidified gas
temperature at least 5 [deg]C above its dewpoint.
    (6) Allow time for the analyzer response to stabilize.
Stabilization time may include time to purge the transfer line and to
account for analyzer response.
    (7) While the analyzer measures the sample's concentration, record
its output for 30 seconds. Calculate the arithmetic mean of this data.
    (8) The analyzer meets the interference verification if the result
of paragraph (d)(7) of this section meets the tolerance in paragraph
(c) of this section.
    (9) You may also run interference procedures for CO2 and
H2O separately. If the CO2 and H2O
levels used are higher than the maximum levels expected during testing,
you may scale down each observed interference value by multiplying the
observed interference by the ratio of the maximum expected
concentration value to the actual value used during this procedure. You
may run the separate interference procedures concentrations of
H2O (down to 0.025 mol/mol H2O content) that are
lower than the maximum levels expected during testing, but you must
scale up the observed H2O interference by multiplying the
observed interference by the ratio of the maximum expected
H2O concentration value to the actual value used during this
procedure. The sum of the two scaled interference values must meet the
tolerance in paragraph (c) of this section.
* * * * *

0
85. Section 1065.360 is revised to read as follows:

Sec.  1065.360  FID optimization and verification.

    (a) Scope and frequency. For all FID analyzers, calibrate the FID
upon initial installation. Repeat the calibration as needed using good
engineering judgment. For a FID that measures THC, perform the
following steps:
    (1) Optimize the response to various hydrocarbons after initial
analyzer installation and after major maintenance as described in
paragraph (c) of this section.
    (2) Determine the methane (CH4) response factor after
initial analyzer installation and after major maintenance as described
in paragraph (d) of this section.
    (3) Verify the methane (CH4) response within 185 days
before testing as described in paragraph (e) of this section.
    (b) Calibration. Use good engineering judgment to develop a
calibration procedure, such as one based on the FID-analyzer
manufacturer's instructions and recommended frequency for calibrating
the FID. Alternately, you may remove system components for off-site
calibration. For a FID that measures THC, calibrate using
C3H8 calibration gases that meet the
specifications of Sec.  1065.750. For a FID that measures
CH4, calibrate using CH4 calibration gases that
meet the specifications of Sec.  1065.750. We recommend FID analyzer
zero and span gases that contain approximately the flow-weighted mean
concentration of O2 expected during testing. If you use a
FID to measure methane (CH4) downstream of a nonmethane
cutter, you may calibrate that FID using CH4 calibration
gases with the cutter. Regardless of the calibration gas composition,
calibrate on a carbon number basis of one (C1). For example,
if you use a C3H8 span gas of concentration 200
[mu]mol/mol, span the FID to respond with a value of 600 [mu]mol/mol.
As another example, if you use a CH4 span gas with a
concentration of 200 [mu]mol/mol, span the FID to respond with a value
of 200 [mu]mol/mol.
    (c) THC FID response optimization. This procedure is only for FID
analyzers that measure THC. Use good engineering judgment for initial
instrument start-up and basic operating adjustment using FID fuel and
zero air. Heated FIDs must be within their required operating
temperature ranges. Optimize FID response at the most

common analyzer range expected during emission testing. Optimization
involves adjusting flows and pressures of FID fuel, burner air, and
sample to minimize response variations to various hydrocarbon species
in the exhaust. Use good engineering judgment to trade off peak FID
response to propane calibration gases to achieve minimal response
variations to different hydrocarbon species. For an example of trading
off response to propane for relative responses to other hydrocarbon
species, see SAE 770141 (incorporated by reference in Sec.  1065.1010).
Determine the optimum flow rates and/or pressures for FID fuel, burner
air, and sample and record them for future reference.
    (d) THC FID CH4 response factor determination. This procedure is
only for FID analyzers that measure THC. Since FID analyzers generally
have a different response to CH4 versus C3H8,
determine each THC FID analyzer's CH4 response factor,
RFCH4[THC-FID], after FID optimization. Use the most recent
RFCH4[THC-FID] measured according to this section in the
calculations for HC determination described in Sec.  1065.660 to
compensate for CH4 response. Determine
RFCH4[THC-FID] as follows, noting that you do not determine
RFCH4[THC-FID] for FIDs that are calibrated and spanned
using CH4 with a nonmethane cutter:
    (1) Select a C3H8 span gas concentration that
you use to span your analyzers before emission testing. Use only span
gases that meet the specifications of Sec.  1065.750. Record the
C3H8 concentration of the gas.
    (2) Select a CH4 span gas concentration that you use to
span your analyzers before emission testing. Use only span gases that
meet the specifications of Sec.  1065.750. Record the CH4
concentration of the gas.
    (3) Start and operate the FID analyzer according to the
manufacturer's instructions.
    (4) Confirm that the FID analyzer has been calibrated using
C3H8. Calibrate on a carbon number basis of one
(C1). For example, if you use a C3H8
span gas of concentration 200 [mu]mol/mol, span the FID to respond with
a value of 600 [mu]mol/mol.
    (5) Zero the FID with a zero gas that you use for emission testing.
    (6) Span the FID with the C3H8 span gas that
you selected under paragraph (d)(1) of this section.
    (7) Introduce at the sample port of the FID analyzer, the
CH4 span gas that you selected under paragraph (d)(2) of
this section.
    (8) Allow time for the analyzer response to stabilize.
Stabilization time may include time to purge the analyzer and to
account for its response.
    (9) While the analyzer measures the CH4 concentration,
record 30 seconds of sampled data. Calculate the arithmetic mean of
these values.
    (10) Divide the mean measured concentration by the recorded span
concentration of the CH4 calibration gas. The result is the
FID analyzer's response factor for CH4, RFCH4[THC-FID].
    (e) THC FID methane (CH4) response verification. This procedure is
only for FID analyzers that measure THC. If the value of
RFCH4[THC-FID] from paragraph (d) of this section is within
5.0% of its most recent previously determined value, the
THC FID passes the methane response verification. For example, if the
most recent previous value for RFCH4[THC-FID] was 1.05 and
it changed by 0.05 to become 1.10 or it changed by -0.05 to
become 1.00, either case would be acceptable because 4.8%
is less than 5.0%. Verify RFCH4[THC-FID] as
follows:
    (1) First verify that the flow rates and/or pressures of FID fuel,
burner air, and sample are each within 0.5% of their most
recent previously recorded values, as described in paragraph (c) of
this section. You may adjust these flow rates as necessary. Then
determine the RFCH4[THC-FID] as described in paragraph (d)
of this section and verify that it is within the tolerance specified in
this paragraph (e).
    (2) If RFCH4[THC-FID] is is not within the tolerance
specified in this paragraph (e), re-optimize the FID response as
described in paragraph (c) of this section.
    (3) Determine a new RFCH4[THC-FID] as described in
paragraph (d) of this section. Use this new value of
RFCH4[THC-FID] in the calculations for HC determination, as
described in Sec.  1065.660.

0
86. Section 1065.362 is amended by revising paragraph (d) to read as
follows:

Sec.  1065.362  Non-stoichiometric raw exhaust FID O2 interference
verification.

* * * * *
    (d) Procedure. Determine FID O2 interference as follows,
noting that you may use one or more gas dividers to create the
reference gas concentrations that are required to perform this
verification:
    (1) Select three span reference gases that contain a
C3H8 concentration that you use to span your
analyzers before emission testing. Use only span gases that meet the
specifications of Sec.  1065.750. You may use CH4 span
reference gases for FIDs calibrated on CH4 with a nonmethane
cutter. Select the three balance gas concentrations such that the
concentrations of O2 and N2 represent the
minimum, maximum, and average O2 concentrations expected
during testing. The requirement for using the average O2
concentration can be removed if you choose to calibrate the FID with
span gas balanced with the average expected oxygen concentration.
    (2) Confirm that the FID analyzer meets all the specifications of
Sec.  1065.360.
    (3) Start and operate the FID analyzer as you would before an
emission test. Regardless of the FID burner's air source during
testing, use zero air as the FID burner's air source for this
verification.
    (4) Zero the FID analyzer using the zero gas used during emission
testing.
    (5) Span the FID analyzer using a span gas that you use during
emission testing.
    (6) Check the zero response of the FID analyzer using the zero gas
used during emission testing. If the mean zero response of 30 seconds
of sampled data is within 0.5% of the span reference value
used in paragraph (d)(5) of this section, then proceed to the next
step; otherwise restart the procedure at paragraph (d)(4) of this
section.
    (7) Check the analyzer response using the span gas that has the
minimum concentration of O2 expected during testing. Record
the mean response of 30 seconds of stabilized sample data as
xO2minHC.
    (8) Check the zero response of the FID analyzer using the zero gas
used during emission testing. If the mean zero response of 30 seconds
of stabilized sample data is within 0.5% of the span
reference value used in paragraph (d)(5) of this section, then proceed
to the next step; otherwise restart the procedure at paragraph (d)(4)
of this section.
    (9) Check the analyzer response using the span gas that has the
average concentration of O2 expected during testing. Record
the mean response of 30 seconds of stabilized sample data as
xO2avgHC.
    (10) Check the zero response of the FID analyzer using the zero gas
used during emission testing. If the mean zero response of 30 seconds
of stabilized sample data is within 0.5% of the span
reference value used in paragraph (d)(5) of this section, proceed to
the next step; otherwise restart the procedure at paragraph (d)(4) of
this section.
    (11) Check the analyzer response using the span gas that has the
maximum concentration of O2 expected during testing. Record
the mean response of 30 seconds of stabilized sample data as
xO2maxHC.
    (12) Check the zero response of the FID analyzer using the zero gas
used during emission testing. If the mean

zero response of 30 seconds of stabilized sample data is within 0.5% of the span reference value used in paragraph (d)(5) of this
section, then proceed to the next step; otherwise restart the procedure
at paragraph (d)(4) of this section.
    (13) Calculate the percent difference between xO2maxHC
and its reference gas concentration. Calculate the percent difference
between xO2avgHC and its reference gas concentration.
Calculate the percent difference between xO2minHC and its
reference gas concentration. Determine the maximum percent difference
of the three. This is the O2 interference.
    (14) If the O2 interference is within 2%,
the FID passes the O2 interference verification; otherwise
perform one or more of the following to address the deficiency:
    (i) Repeat the verification to determine if a mistake was made
during the procedure.
    (ii) Select zero and span gases for emission testing that contain
higher or lower O2 concentrations and repeat the
verification.
    (iii) Adjust FID burner air, fuel, and sample flow rates. Note that
if you adjust these flow rates on a THC FID to meet the O2
interference verification, you have reset RFCH4 for the next
RFCH4 verification according to Sec.  1065.360. Repeat the
O2 interference verification after adjustment and determine
RFCH4.
    (iv) Repair or replace the FID and repeat the O2
interference verification.
    (v) Demonstrate that the deficiency does not adversely affect your
ability to demonstrate compliance with the applicable emission
standards.
0
87. Section 1065.365 is revised to read as follows:

Sec.  1065.365  Nonmethane cutter penetration fractions.

    (a) Scope and frequency. If you use a FID analyzer and a nonmethane
cutter (NMC) to measure methane (CH4), determine the
nonmethane cutter's penetration fractions of methane, PFCH4,
and ethane, PFC2H6. As detailed in this section, these
penetration fractions may be determined as a combination of NMC
penetration fractions and FID analyzer response factors, depending on
your particular NMC and FID analyzer configuration. Perform this
verification after installing the nonmethane cutter. Repeat this
verification within 185 days of testing to verify that the catalytic
activity of the cutter has not deteriorated. Note that because
nonmethane cutters can deteriorate rapidly and without warning if they
are operated outside of certain ranges of gas concentrations and
outside of certain temperature ranges, good engineering judgment may
dictate that you determine a nonmethane cutter's penetration fractions
more frequently.
    (b) Measurement principles. A nonmethane cutter is a heated
catalyst that removes nonmethane hydrocarbons from an exhaust sample
stream before the FID analyzer measures the remaining hydrocarbon
concentration. An ideal nonmethane cutter would have a methane
penetration fraction, PFCH4, of 1.000, and the penetration
fraction for all other nonmethane hydrocarbons would be 0.000, as
represented by PFC2H6. The emission calculations in Sec.
1065.660 use the measured values from this verification to account for
less than ideal NMC performance.
    (c) System requirements. We do not limit NMC penetration fractions
to a certain range. However, we recommend that you optimize a
nonmethane cutter by adjusting its temperature to achieve a
PFCH4 >0.85 and a PFC2H6 <0.02, as determined by
paragraphs (d), (e), or (f) of this section, as applicable. If we use a
nonmethane cutter for testing, it will meet this recommendation. If
adjusting NMC temperature does not result in achieving both of these
specifications simultaneously, we recommend that you replace the
catalyst material. Use the most recently determined penetration values
from this section to calculate HC emissions according to Sec.  1065.660
and Sec.  1065.665 as applicable.
    (d) Procedure for a FID calibrated with the NMC. The method
described in this paragraph (d) is recommended over the procedures
specified in paragraphs (e) and (f) of this section. If your FID
arrangement is such that a FID is always calibrated to measure
CH4 with the NMC, then span that FID with the NMC using a
CH4 span gas, set the product of that FID's CH4
response factor and CH4 penetration fraction,
RFPFCH4[NMC-FID], equal to 1.0 for all emission
calculations, and determine its combined ethane
(C2H6) response factor and penetration fraction,
RFPFC2H6[NMC-FID] as follows:
    (1) Select a CH4 gas mixture and a
C2H6 analytical gas mixture and ensure that both
mixtures meet the specifications of Sec.  1065.750. Select a
CH4 concentration that you would use for spanning the FID
during emission testing and select a C2H6
concentration that is typical of the peak NMHC concentration expected
at the hydrocarbon standard or equal to THC analyzer's span value.
    (2) Start, operate, and optimize the nonmethane cutter according to
the manufacturer's instructions, including any temperature
optimization.
    (3) Confirm that the FID analyzer meets all the specifications of
Sec.  1065.360.
    (4) Start and operate the FID analyzer according to the
manufacturer's instructions.
    (5) Zero and span the FID with the cutter and use CH4
span gas to span the FID with the cutter. Note that you must span the
FID on a C1 basis. For example, if your span gas has a CH4
reference value of 100 [mu]mol/mol, the correct FID response to that
span gas is 100 [mu]mol/mol because there is one carbon atom per
CH4 molecule.
    (6) Introduce the C2H6 analytical gas mixture
upstream of the nonmethane cutter.
    (7) Allow time for the analyzer response to stabilize.
Stabilization time may include time to purge the nonmethane cutter and
to account for the analyzer's response.
    (8) While the analyzer measures a stable concentration, record 30
seconds of sampled data. Calculate the arithmetic mean of these data
points.
    (9) Divide the mean by the reference value of
C2H6, converted to a C1 basis. The
result is the C2H6 combined response factor and
penetration fraction, RFPFC2H6[NMC-FID]. Use this combined
response factor and penetration fraction and the product of the
CH4 response factor and CH4 penetration fraction,
RFPFCH4[NMC-FID], set to 1.0 in emission calculations
according to Sec.  1065.660(b)(2)(i) or Sec.  1065.665, as applicable.
    (e) Procedure for a FID calibrated with propane, bypassing the NMC.
If you use a FID with an NMC that is calibrated with propane,
C3H8, by bypassing the NMC, determine its
penetration fractions, PFC2H6[NMC-FID] and
PFCH4[NMC-FID], as follows:
    (1) Select CH4 and C2H6 analytical
gas mixtures that meet the specifications of Sec.  1065.750 with the
CH4 concentration typical of its peak concentration expected
at the hydrocarbon standard and the C2H6
concentration typical of the peak total hydrocarbon (THC) concentration
expected at the hydrocarbon standard or the THC analyzer span value.
    (2) Start and operate the nonmethane cutter according to the
manufacturer's instructions, including any temperature optimization.
    (3) Confirm that the FID analyzer meets all the specifications of
Sec.  1065.360.
    (4) Start and operate the FID analyzer according to the
manufacturer's instructions.
    (5) Zero and span the FID as you would during emission testing.
Span the FID by bypassing the cutter and by

using C3H8 span gas to span the FID. Note that
you must span the FID on a C1 basis. For example, if your
span gas has a propane reference value of 100 [mu]mol/mol, the correct
FID response to that span gas is 300 [mu]mol/mol because there are
three carbon atoms per C3H8 molecule.
    (6) Introduce the C2H6 analytical gas mixture
upstream of the nonmethane cutter at the same point the zero gas was
introduced.
    (7) Allow time for the analyzer response to stabilize.
Stabilization time may include time to purge the nonmethane cutter and
to account for the analyzer's response.
    (8) While the analyzer measures a stable concentration, record 30
seconds of sampled data. Calculate the arithmetic mean of these data
points.
    (9) Reroute the flow path to bypass the nonmethane cutter,
introduce the C2H6 analytical gas mixture to the
bypass, and repeat the steps in paragraphs (e)(7) through (8) of this
section.
    (10) Divide the mean C2H6 concentration
measured through the nonmethane cutter by the mean concentration
measured after bypassing the nonmethane cutter. The result is the
C2H6 penetration fraction,
PFC2H6[NMC-FID]. Use this penetration fraction according to
Sec.  1065.660(b)(2)(ii) or Sec.  1065.665, as applicable.
    (11) Repeat the steps in paragraphs (e)(6) through (10) of this
section, but with the CH4 analytical gas mixture instead of
C2H6. The result will be the CH4
penetration fraction, PFCH4[NMC-FID]. Use this penetration
fraction according to Sec.  1065.660(b)(2)(ii) or Sec.  1065.665, as
applicable.
    (f) Procedure for a FID calibrated with methane, bypassing the NMC.
If you use a FID with an NMC that is calibrated with methane,
CH4, by bypassing the NMC, determine its combined ethane
(C2H6) response factor and penetration fraction,
RFPFC2H6[NMC-FID], as well as its CH4 penetration
fraction, PFCH4[NMC-FID], as follows:
    (1) Select CH4 and C2H6 analytical
gas mixtures that meet the specifications of Sec.  1065.750, with the
CH4 concentration typical of its peak concentration expected
at the hydrocarbon standard and the C2H6
concentration typical of the peak total hydrocarbon (THC) concentration
expected at the hydrocarbon standard or the THC analyzer span value.
    (2) Start and operate the nonmethane cutter according to the
manufacturer's instructions, including any temperature optimization.
    (3) Confirm that the FID analyzer meets all the specifications of
Sec.  1065.360.
    (4) Start and operate the FID analyzer according to the
manufacturer's instructions.
    (5) Zero and span the FID as you would during emission testing.
Span the FID with CH4 span gas by bypassing the cutter. Note
that you must span the FID on a C1 basis. For example, if
your span gas has a methane reference value of 100 [mu]mol/mol, the
correct FID response to that span gas is 100 [mu]mol/mol because there
is one carbon atom per CH4 molecule.
    (6) Introduce the C2H6 analytical gas mixture
upstream of the nonmethane cutter at the same point the zero gas was
introduced.
    (7) Allow time for the analyzer response to stabilize.
Stabilization time may include time to purge the nonmethane cutter and
to account for the analyzer's response.
    (8) While the analyzer measures a stable concentration, record 30
seconds of sampled data. Calculate the arithmetic mean of these data
points.
    (9) Reroute the flow path to bypass the nonmethane cutter,
introduce the C2H6 analytical gas mixture to the
bypass, and repeat the steps in paragraphs (e)(7) and (8) of this
section.
    (10) Divide the mean C2H6 concentration
measured through the nonmethane cutter by the mean concentration
measured after bypassing the nonmethane cutter. The result is the
C2H6 combined response factor and penetration
fraction, RFPFC2H6[NMC-FID]. Use this combined response
factor and penetration fraction according to Sec.  1065.660(b)(2)(iii)
or Sec.  1065.665, as applicable.
    (11) Repeat the steps in paragraphs (e)(6) through (10) of this
section, but with the CH4 analytical gas mixture instead of
C2H6. The result will be the CH4
penetration fraction, PFCH4[NMC-FID]. Use this penetration
fraction according to Sec.  1065.660(b)(2)(iii) or Sec.  1065.665, as
applicable.

0
88. Section 1065.370 is amended by revising paragraphs (d), (e), and
(g)(1) to read as follows:

Sec.  1065.370  CLD CO2 and H2O quench verification.

* * * * *
    (d) CO2 quench verification procedure. Use the following
method to determine CO2 quench, or use good engineering
judgment to develop a different protocol:
    (1) Use PTFE or stainless steel tubing to make necessary
connections.
    (2) Connect a pressure-regulated CO2 span gas to the
port of a gas divider that meets the specifications in Sec.  1065.248
at the appropriate time. Use a CO2 span gas that meets the
specifications of Sec.  1065.750 and attempt to use a concentration
that is approximately twice the maximum CO2 concentration
expected to enter the CLD sample port during testing, if available.
    (3) Connect a pressure-regulated purified N2 gas to the
port of a gas divider that meets the specifications in Sec.  1065.248
at the appropriate time. Use a purified N2 gas that meets
the specifications of Sec.  1065.750.
    (4) Connect a pressure-regulated NO span gas to the port of the gas
divider that meets the specifications in Sec.  1065.248. Use an NO span
gas that meets the specifications of Sec.  1065.750. Attempt to use an
NO concentration that is approximately twice the maximum NO
concentration expected during testing, if available.
    (5) Configure the gas divider such that nearly equal amounts of the
span gas and balance gas are blended with each other. Apply viscosity
corrections as necessary to appropriately ensure correct gas division.
    (6) While flowing NO and CO2 through the gas divider,
stabilize the CO2 concentration downstream of the gas
divider and measure the CO2 concentration with an NDIR
analyzer that has been prepared for emission testing. You may
alternatively determine the CO2 concentration from the gas
divider cut-point, applying viscosity correction as necessary to ensure
accurate gas division. Record this concentration, xCO2meas,
and use it in the quench verification calculations in Sec.  1065.675.
    (7) Measure the NO concentration downstream of the gas divider. If
the CLD has an operating mode in which it detects NO-only, as opposed
to total NOX, operate the CLD in the NO-only operating mode.
Record this concentration, xNO,CO2, and use it in the quench
verification calculations in Sec.  1065.675.
    (8) Switch the flow of CO2 off and start the flow of
100% purified N2 to the inlet port of the gas divider.
Monitor the CO2 at the gas divider's outlet until its
concentration stabilizes at zero.
    (9) Measure NO concentration at the gas divider's outlet. Record
this value, xNO,N2, and use it in the quench verification
calculations in Sec.  1065.675.
    (10) Use the values recorded according to this paragraph (d) of
this section and paragraph (e) of this section to calculate quench as
described in Sec.  1065.675.
    (e) H2O quench verification procedure. Use the following method to
determine H2O quench, or use good

engineering judgment to develop a different protocol:
    (1) Use PTFE or stainless steel tubing to make necessary
connections.
    (2) If the CLD has an operating mode in which it detects NO-only,
as opposed to total NOX, operate the CLD in the NO-only
operating mode.
    (3) Measure an NO calibration span gas that meets the
specifications of Sec.  1065.750 and is near the maximum concentration
expected during testing. Record this concentration, xNOdry.
    (4) Humidify the NO span gas by bubbling it through distilled water
in a sealed vessel. If the sample is not passed through a dryer,
control the vessel temperature to generate an H2O level at least as
high as the maximum expected during testing. If the sample is passed
through a dryer during testing, control the vessel temperature to
generate an H2O level at least as high as the level
determined in Sec.  1065.145(d)(2). We recommend that you humidify the
gas to the highest sample dewpoint that you estimate at the CLD inlet
during emission sampling. Regardless of the humidity during this test,
the quench verification calculations in Sec.  1065.675 scale the
recorded quench to the highest dewpoint expected for flow entering the
CLD sample port during emission sampling.
    (5) Introduce the humidified NO test gas into the sample system.
You may introduce it downstream of any sample dryer, if one is used
during testing.
    (6) Measure the humidified gas dewpoint, Tdew, and pressure,
ptotal, as close as possible to the analyzer inlet.
    (7) Downstream of the vessel, maintain the humidified NO test gas
temperature at least 5 [deg]C above its dewpoint.
    (8) Allow time for the analyzer response to stabilize.
Stabilization time may include time to purge the transfer line and to
account for analyzer response.
    (9) While the analyzer measures the sample's concentration, record
the analyzer's output for 30 seconds. Calculate the arithmetic mean of
these data. This mean is xNOmeas.
    (10) Set xNOwet equal to xNOmeas from paragraph (e)(9) of this
section.
    (11) Use xNOwet to calculate the quench according to Sec.
1065.675.
* * * * *
    (g) * * *
    (1) You may omit this verification if you can show by engineering
analysis that for your NOX sampling system and your emission
calculations procedures, the combined CO2 and H2O interference for your
NOX CLD analyzer always affects your brake-specific
NOX emission results within no more than 1.0% of
the applicable NOX standard.
* * * * *

0
89. Section 1065.372 is amended by revising paragraphs (d)(7) and
(e)(1) to read as follows:

Sec.  1065.372  NDUV analyzer HC and H2O interference
verification.

* * * * *
    (d) * * *
    (7) Multiply this difference by the ratio of the flow-weighted mean
HC concentration expected at the standard to the HC concentration
measured during the verification. The analyzer meets the interference
verification of this section if this result is within 2% of
the NOX concentration expected at the standard.
    (e) * * *
    (1) You may omit this verification if you can show by engineering
analysis that for your NOX sampling system and your emission
calculations procedures, the combined HC and H2O
interference for your NOX NDUV analyzer always affects your
brake-specific NOX emission results by less than 0.5% of the
applicable NOX standard.
* * * * *

0
90. Section 1065.376 is revised to read as follows:

Sec.  1065.376  Chiller NO2 penetration.

    (a) Scope and frequency. If you use a chiller to dry a sample
upstream of a NOX measurement instrument, but you don't use
an NO2-to-NO converter upstream of the chiller, you must perform this
verification for chiller NO2 penetration. Perform this verification
after initial installation and after major maintenance.
    (b) Measurement principles. A chiller removes water, which can
otherwise interfere with a NOX measurement. However, liquid
water remaining in an improperly designed chiller can remove NO2 from
the sample. If a chiller is used without an NO2-to-NO converter
upstream, it could remove NO2 from the sample prior NOX
measurement.
    (c) System requirements. A chiller must allow for measuring at
least 95% of the total NO2 at the maximum expected concentration of
NO2.
    (d) Procedure. Use the following procedure to verify chiller
performance:
    (1) Instrument setup. Follow the analyzer and chiller
manufacturers' start-up and operating instructions. Adjust the analyzer
and chiller as needed to optimize performance.
    (2) Equipment setup and data collection. (i) Zero and span the
total NOX gas analyzer(s) as you would before emission
testing.
    (ii) Select an NO2 calibration gas, balance gas of dry air, that
has an NO2 concentration within 5% of the maximum NO2
concentration expected during testing.
    (iii) Overflow this calibration gas at the gas sampling system's
probe or overflow fitting. Allow for stabilization of the total
NOX response, accounting only for transport delays and
instrument response.
    (iv) Calculate the mean of 30 seconds of recorded total
NOX data and record this value as NOXref.
    (v) Stop flowing the NO2 calibration gas.
    (vi) Next saturate the sampling system by overflowing a dewpoint
generator's output, set at a dewpoint of 50 [deg]C, to the gas sampling
system's probe or overflow fitting. Sample the dewpoint generator's
output through the sampling system and chiller for at least 10 minutes
until the chiller is expected to be removing a constant rate of water.
    (vii) Immediately switch back to overflowing the NO2 calibration
gas used to establish xNOxref. Allow for stabilization of
the total NOX response, accounting only for transport delays
and instrument response. Calculate the mean of 30 seconds of recorded
total NOX data and record this value as xNOxmeas.
    (viii) Correct xNOxmeas to xNOxdry based upon
the residual water vapor that passed through the chiller at the
chiller's outlet temperature and pressure.
    (3) Performance evaluation. If xNOxdry is less than 95%
of xNOxref, repair or replace the chiller.
    (e) Exceptions. The following exceptions apply:
    (1) You may omit this verification if you can show by engineering
analysis that for your NOX sampling system and your emission
calculations procedures, the chiller always affects your brake-specific
NOX emission results by less than 0.5% of the applicable
NOX standard.
    (2) You may use a chiller that you determine does not meet this
verification, as long as you try to correct the problem and the
measurement deficiency does not adversely affect your ability to show
that engines comply with all applicable emission standards.
0
91. Section 1065.378 is amended by revising paragraphs (d) and (e)(1)
to read as follows:

Sec.  1065.378  NO2-to-NO converter conversion verification.

* * * * *
    (d) Procedure. Use the following procedure to verify the
performance of a NO2-to-NO converter:

    (1) Instrument setup. Follow the analyzer and NO2-to-NO converter
manufacturers' start-up and operating instructions. Adjust the analyzer
and converter as needed to optimize performance.
    (2) Equipment setup. Connect an ozonator's inlet to a zero-air or
oxygen source and connect its outlet to one port of a three-way tee
fitting. Connect an NO span gas to another port, and connect the NO2-
to-NO converter inlet to the last port.
    (3) Adjustments and data collection. Perform this check as follows:
    (i) Set ozonator air off, turn ozonator power off, and set the
analyzer to NO mode. Allow for stabilization, accounting only for
transport delays and instrument response.
    (ii) Use an NO concentration that is representative of the peak
total NOX concentration expected during testing. The NO2
content of the gas mixture shall be less than 5% of the NO
concentration. Record the concentration of NO by calculating the mean
of 30 seconds of sampled data from the analyzer and record this value
as xNOref.
    (iii) Turn on the ozonator O2 supply and adjust the
O2 flow rate so the NO indicated by the analyzer is about 10
percent less than xNOref. Record the concentration of NO by
calculating the mean of 30 seconds of sampled data from the analyzer
and record this value as xNO+O2mix.
    (iv) Switch the ozonator on and adjust the ozone generation rate so
the NO measured by the analyzer is 20 percent of xNOref,
while maintaining at least 10 percent unreacted NO. Record the
concentration of NO by calculating the mean of 30 seconds of sampled
data from the analyzer and record this value as xNOmeas.
    (v) Switch the NOX analyzer to NOX mode and
measure total NOX. Record the concentration of
NOX by calculating the mean of 30 seconds of sampled data
from the analyzer and record this value as xNOxmeas.
    (vi) Switch off the ozonator but maintain gas flow through the
system. The NOX analyzer will indicate the NOX in
the NO + O2 mixture. Record the concentration of
NOX by calculating the mean of 30 seconds of sampled data
from the analyzer and record this value as xNOx+O2mix.
    (vii) Turn off the ozonator O2 supply. The
NOX analyzer will indicate the NOX in the
original NO-in-N2 mixture. Record the concentration of
NOX by calculating the mean of 30 seconds of sampled data
from the analyzer and record this value as xNOxref. This
value should be no more than 5 percent above the xNOref
value.
    (4) Performance evaluation. Calculate the efficiency of the
NOX converter efficiency by substituting the concentrations
obtained into the following equation:
[GRAPHIC] [TIFF OMITTED] TR06MY08.021

    (5) If the result is less than 95%, repair or replace the
NO2-to-NO converter.
    (e) * * *
    (1) You may omit this verification if you can show by engineering
analysis that for your NOX sampling system and your emission
calculations procedures, the converter always affects your brake-
specific NOX emission results by less than 0.5% of the
applicable NOX standard.
* * * * *

0
92. Section 1065.390 is revised to read as follows:

Sec.  1065.390  PM balance verifications and weighing process
verification.

    (a) Scope and frequency. This section describes three
verifications.
    (1) Independent verification of PM balance performance within 370
days before weighing any filter.
    (2) Zero and span the balance within 12 h before weighing any
filter.
    (3) Verify that the mass determination of reference filters before
and after a filter weighing session are less than a specified
tolerance.
    (b) Independent verification. Have the balance manufacturer (or a
representative approved by the balance manufacturer) verify the balance
performance within 370 days of testing.
    (c) Zeroing and spanning. You must verify balance performance by
zeroing and spanning it with at least one calibration weight, and any
weights you use must that meet the specifications in Sec.  1065.790 to
perform this verification.
    (1) Use a manual procedure in which you zero the balance and span
the balance with at least one calibration weight. If you normally use
mean values by repeating the weighing process to improve the accuracy
and precision of PM measurements, use the same process to verify
balance performance.
    (2) You may use an automated procedure to verify balance
performance. For example many balances have internal calibration
weights that are used automatically to verify balance performance. Note
that if you use internal balance weights, the weights must meet the
specifications in Sec.  1065.790 to perform this verification.
    (d) Reference sample weighing. Verify all mass readings during a
weighing session by weighing reference PM sample media (e.g. filters)
before and after a weighing session. A weighing session may be as short
as desired, but no longer than 80 hours, and may include both pre-test
and post-test mass readings. We recommend that weighing sessions be
eight hours or less. Successive mass determinations of each reference
PM sample media (e.g., filter) must return the same value within 10 [mu]g or 10% of the net PM mass expected at the
standard (if known), whichever is higher. If successive reference PM
sample media (e.g. filter) weighing events fail this criterion,
invalidate all individual test media (e.g., filter) mass readings
occurring between the successive reference media (e.g., filter) mass
determinations. You may reweigh these media (e.g. filter) in another
weighing session. If you invalidate a pre-test media (e.g. filter) mass
determination, that test interval is void. Perform this verification as
follows:
    (1) Keep at least two samples of unused PM sample media (e.g.,,
filters) in the PM-stabilization environment. Use these as references.
If you collect PM with filters, select unused filters of the same
material and size for use as references. You may periodically replace
references, using good engineering judgment.
    (2) Stabilize references in the PM stabilization environment.
Consider references stabilized if they have been in the PM-
stabilization environment for a minimum of 30 min, and the PM-
stabilization environment has been within the specifications of Sec.
1065.190(d) for at least the preceding 60 min.
    (3) Exercise the balance several times with a reference sample. We
recommend weighing ten samples without recording the values.
    (4) Zero and span the balance. Using good engineering judgment,
place a test mass such as a calibration weight on the balance, then
remove it. After spanning,

confirm that the balance returns to a zero reading within the normal
stabilization time.
    (5) Weigh each of the reference media (e.g., filters) and record
their masses. We recommend using substitution weighing as described in
Sec.  1065.590(j). If you normally use mean values by repeating the
weighing process to improve the accuracy and precision of the reference
media (e.g., filter) mass, you must use mean values of sample media
(e.g., filter) masses.
    (6) Record the balance environment dewpoint, ambient temperature,
and atmospheric pressure.
    (7) Use the recorded ambient conditions to correct results for
buoyancy as described in Sec.  1065.690. Record the buoyancy-corrected
mass of each of the references.
    (8) Subtract each reference media's (e.g., filter's) buoyancy-
corrected reference mass from its previously measured and recorded
buoyancy-corrected mass.
    (9) If any of the reference filters' observed mass changes by more
than that allowed under this paragraph, you must invalidate all PM mass
determinations made since the last successful reference media (e.g.,
filter) mass validation. You may discard reference PM media (e.g.,
filters) if only one one of the filter's mass changes by more than the
allowable amount and you can positively identify a special cause for
that filter's mass change that would not have affected other in-process
filters. Thus, the validation can be considered a success. In this
case, you do not have to include the contaminated reference media when
determining compliance with paragraph (d)(10) of this section, but the
affected reference filter must be immediately discarded and replaced
prior to the next weighing session.
    (10) If any of the reference masses change by more than that
allowed under this paragraph (d), invalidate all PM results that were
determined between the two times that the reference masses were
determined. If you discarded reference PM sample media according to
paragraph (d)(9) of this section, you must still have at least one
reference mass difference that meets the criteria in this paragraph
(d). Otherwise, you must invalidate all PM results that were determined
between the two times that the reference media (e.g., filters) masses
were determined.

Subpart E--[Amended]

0
93. Section 1065.405 is revised to read as follows:

Sec.  1065.405  Test engine preparation and maintenance.

    This part 1065 describes how to test engines for a variety of
purposes, including certification testing, production-line testing, and
in-use testing. Depending on which type of testing is being conducted,
different preparation and maintenance requirements apply for the test
engine.
    (a) If you are testing an emission-data engine for certification,
make sure it is built to represent production engines. This includes
governors that you normally install on production engines. Production
engines should also be tested with their installed governors. If you do
not install governors on production engines, simulate a governor that
is representative of a governor that others will install on your
production engines.
    (b) Testing generally occurs only after the test engine has
undergone a stabilization step (or in-use operation). If the engine has
not already been stabilized, run the test engine, with all emission
control systems operating, long enough to stabilize emission levels.
Note that you must generally use the same stabilization procedures for
emission-data engines for which you apply the same deterioration
factors so low-hour emission-data engines are consistent with the low-
hour engine used to develop the deterioration factor.
    (1) Unless otherwise specified in the standard-setting part, you
may consider emission levels stable without measurement after 50 h of
operation. If the engine needs less operation to stabilize emission
levels, record your reasons and the methods for doing this, and give us
these records if we ask for them. If the engine will be tested for
certification as a low-hour engine, see the standard-setting part for
limits on testing engines to establish low-hour emission levels.
    (2) You may stabilize emissions from a catalytic exhaust
aftertreatment device by operating it on a different engine, consistent
with good engineering judgment. Note that good engineering judgment
requires that you consider both the purpose of the test and how your
stabilization method will affect the development and application of
deterioration factors. For example, this method of stabilization is
generally not appropriate for production engines. We may also allow you
to stabilize emissions from a catalytic exhaust aftertreatment device
by operating it on an engine-exhaust simulator.
    (c) Record any maintenance, modifications, parts changes,
diagnostic or emissions testing and document the need for each event.
You must provide this information if we request it.
    (d) For accumulating operating hours on your test engines, select
engine operation that represents normal in-use operation for the engine
family.
    (e) If your engine will be used in a vehicle equipped with a
canister for storing evaporative hydrocarbons for eventual combustion
in the engine and the test sequence involves a cold-start or hot-start
duty cycle, attach a canister to the engine before running an emission
test. You may omit using an evaporative canister for any hot-stabilized
duty cycles. You may request to omit using an evaporative canister
during testing if you can show that it would not affect your ability to
show compliance with the applicable emission standards. You may operate
the engine without an installed canister for service accumulation.
Prior to an emission test, use the following steps to attach a canister
to your engine:
    (1) Use a canister and plumbing arrangement that represents the in-
use configuration of the largest capacity canister in all expected
applications.
    (2) Use a canister that is fully loaded with fuel vapors.
    (3) Connect the canister's purge port to the engine.
    (4) Plug the canister port that is normally connected to the fuel
tank.

0
94. Section 1065.410 is amended by revising paragraphs (c) and (d) to
read as follows:

Sec.  1065.410  Maintenance limits for stabilized test engines.

* * * * *
    (c) Keep a record of the inspection and update your application to
document any changes as a result of the inspection. You may use
equipment, instruments, or engineering grade tools to identify bad
engine components. Any equipment, instruments, or tools used for
scheduled maintenance on emission data engines must be representative
of what is planned to be available to dealerships and other service
outlets.
    (d) 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 an
emission-data engine. Also, if your test engine has a major mechanical
failure that requires you to take it apart, you may no longer use it as
an emission-data engine.
* * * * *

0
95. Section 1065.415 is amended by revising the introductory text and
removing paragraph (a)(3) to read as follows:

Sec.  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 or by using
duty cycles that are more aggressive than in-use operation, subject to
any pre-approval requirements established in the applicable standard-
setting part.
* * * * *

0
96. The heading to subpart F of part 1065 is revised to read as
follows:

Subpart F--Performing an Emission Test Over Specified Duty Cycles

    97. Section 1065.501 is amended by revising paragraphs (a)
introductory text, (a)(1), and (b) to read as follows:

Sec.  1065.501  Overview.

    (a) Use the procedures detailed in this subpart to measure engine
emissions over a specified duty cycle. Refer to subpart J of this part
for field test procedures that describe how to measure emissions during
in-use engine operation. This section describes how to:
    (1) Map your engine, if applicable, by recording specified speed
and torque data, as measured from the engine's primary output shaft.
* * * * *
    (b) An emission test generally consists of measuring emissions and
other parameters while an engine follows one or more duty cycles that
are specified in the standard-setting part. There are two general types
of duty cycles:
    (1) Transient cycles. Transient duty cycles are typically specified
in the standard-setting part as a second-by-second sequence of speed
commands and normalized torque (or power) commands. Operate an engine
over a transient cycle such that the speed and torque of the engine's
primary output shaft follows the target values. Proportionally sample
emissions and other parameters and use the calculations in subpart G of
this part to calculate emissions. Start a transient test according to
the standard-setting part, as follows:
    (i) A cold-start transient cycle where you start to measure
emissions just before starting an engine that has not been warmed up.
    (ii) A hot-start transient cycle where you start to measure
emissions just before starting a warmed-up engine.
    (iii) A hot running transient cycle where you start to measure
emissions after an engine is started, warmed up, and running.
    (2) Steady-state cycles. Steady-state duty cycles are typically
specified in the standard-setting part as a list of discrete operating
points (modes or notches), where each operating point has one value of
a normalized speed command and one value of a normalized torque (or
power) command. Ramped-modal cycles for steady-state testing also list
test times for each mode and transition times between modes where speed
and torque are linearly ramped between modes, even for cycles with %
power. Start a steady-state cycle as a hot running test, where you
start to measure emissions after an engine is started, warmed up and
running. You may run a steady-state duty cycle as a discrete-mode cycle
or a ramped-modal cycle, as follows:
    (i) Discrete-mode cycles. Before emission sampling, stabilize an
engine at the first discrete mode. Sample emissions and other
parameters for that mode and then stop emission sampling. Record mean
values for that mode, and then stabilize the engine at the next mode.
Continue to sample each mode discretely and calculate weighted emission
results according to the standard-setting part.
    (ii) Ramped-modal cycles. Perform ramped-modal cycles similar to
the way you would perform transient cycles, except that ramped-modal
cycles involve mostly steady-state engine operation. Generate a ramped-
modal duty cycle as a sequence of second-by-second (1 Hz) reference
speed and torque points. Run the ramped-modal duty cycle in the same
manner as a transient cycle and use the 1 Hz reference speed and torque
values to validate the cycle, even for cycles with % power.
Proportionally sample emissions and other parameters during the cycle
and use the calculations in subpart G of this part to calculate
emissions.
* * * * *

0
98. Section 1065.510 is revised to read as follows:

Sec.  1065.510  Engine mapping.

    (a) Applicability, scope, and frequency. An engine map is a data
set that consists of a series of paired data points that represent the
maximum brake torque versus engine speed, measured at the engine's
primary output shaft. Map your engine if the standard-setting part
requires engine mapping to generate a duty cycle for your engine
configuration. Map your engine while it is connected to a dynamometer
or other device that can absorb work output from the engine's primary
output shaft according to Sec.  1065.110. Configure any auxiliary work
inputs and outputs such as hybrid, turbo-compounding, or thermoelectric
systems to represent their in-use configurations, and use the same
configuration for emission testing. See Figure 1 of Sec.  1065.210.
This may involve configuring initial states of charge and rates and
times of auxiliary-work inputs and outputs. We recommend that you
contact the Designated Compliance Officer before testing to determine
how you should configure any auxiliary-work inputs and outputs. Use the
most recent engine map to transform a normalized duty cycle from the
standard-setting part to a reference duty cycle specific to your
engine. Normalized duty cycles are specified in the standard-setting
part. You may update an engine map at any time by repeating the engine-
mapping procedure. You must map or re-map an engine before a test if
any of the following apply:
    (1) If you have not performed an initial engine map.
    (2) If the atmospheric pressure near the engine's air inlet is not
within  5 kPa of the atmospheric pressure recorded at the
time of the last engine map.
    (3) If the engine or emission-control system has undergone changes
that might affect maximum torque performance. This includes changing
the configuration of auxiliary work inputs and outputs.
    (4) If 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 often as necessary to capture a complete map within
the specified time.
    (b) Mapping variable-speed engines. Map variable-speed engines as
follows:
    (1) Record the atmospheric pressure.
    (2) Warm up the engine by operating it. We recommend operating the
engine at any speed and at approximately 75% of its expected maximum
power. Continue the warm-up until the engine coolant, block, or head
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 idle speed.
    (i) For engines with a low-speed governor, set the operator demand
to minimum, use the dynamometer or other loading device to target a
torque of zero on the engine's primary output shaft, and allow the
engine to govern the speed. Measure this warm idle speed; we recommend
recording at least 30

values of speed and using the mean of those values.
    (ii) For engines without a low-speed governor, set the dynamometer
to target a torque of zero on the engine's primary output shaft, and
manipulate the operator demand to control the speed to target the
manufacturer-declared value for the lowest engine speed possible with
minimum load (also known as manufacturer-declared warm idle speed).
    (iii) For all variable-speed engines (with or without a low-speed
governor), if a nonzero idle torque is representative of in-use
operation, you may target the manufacturer-declared idle torque. If you
measure the warm idle speed with the manufacturer-declared torque at
this step, you may omit the speed measurement in paragraph (b)(6) of
this section.
    (4) Set operator demand to maximum and control engine speed at (95
 1) % of its warm idle speed determined above for at least
15 seconds. For engines with reference duty cycles whose lowest speed
is greater than warm idle speed, you may start the map at (95  1) % of the lowest reference speed.
    (5) Perform one of the following:
    (i) For any engine subject only to steady-state duty cycles (i.e.,
discrete-mode or ramped-modal), you may perform an engine map by using
discrete speeds. Select at least 20 evenly spaced setpoints between
warm idle and the highest speed above maximum mapped power at which (50
to 75)% of maximum power occurs. If this highest speed is unsafe or
unrepresentative (e.g., for ungoverned engines), use good engineering
judgment to map up to the maximum safe speed or the maximum
representative speed. At each setpoint, stabilize speed and allow
torque to stabilize. Record the mean speed and torque at each setpoint.
We recommend that you stabilize an engine for at least 15 seconds at
each setpoint and record the mean feedback speed and torque of the last
(4 to 6) seconds. Use linear interpolation to determine intermediate
speeds and torques. Use this series of speeds and torques to generate
the power map as described in paragraph (e) of this section.
    (ii) For any variable-speed engine, you may perform an engine map
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 idle to the highest speed above maximum power at which (50
to 75)% of maximum power occurs. If this highest speed is unsafe or
unrepresentative (e.g., for ungoverned engines), use good engineering
judgment to map up to the maximum safe speed or the maximum
representative speed. 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
speeds and torques to generate the power map as described in paragraph
(e) of this section.
    (6) For engines with a low-speed governor, if a nonzero idle torque
is representative of in-use operation, operate the engine at warm idle
with the manufacturer-declared idle torque. Set the operator demand to
minimum, use the dynamometer to target the declared idle torque, and
allow the engine to govern the speed. Measure this speed and use it as
the warm idle speed for cycle generation in Sec.  1065.512. We
recommend recording at least 30 values of speed and using the mean of
those values. You may map the idle governor at multiple load levels and
use this map to determine the measured warm idle speed at the declared
idle torque.
    (c) Negative torque mapping. If your engine is subject to a
reference duty cycle that specifies negative torque values (i.e.,
engine motoring), 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 (b) of this section with minimum operator
demand.
    (3) Determine the amount of negative torque required to motor the
engine at the following two points near the ends of the engine's speed
range. Operate the engine at these two points at minimum operator
demand. Use linear interpolation to determine intermediate values.
    (i) Low-speed point. For engines without a low-speed governor,
determine the amount of negative torque at warm idle speed. For engines
with a low-speed governor, motor the engine above warm idle speed so
the governor is inactive and determine the amount of negative torque at
that speed.
    (ii) High-speed point. For engines without a high-speed governor,
determine the amount of negative torque at the maximum safe speed or
the maximum representative speed. For engines with a high-speed
governor, determine the amount of negative torque at a speed at or