dynamometer, void the results and repeat measurements after making any
necessary corrections. You may void and repeat the entire map sequence,
or you may void and replace only the results for establishing warm
high-idle speed; use good engineering judgment to warm-up the engine
before repeating measurements.
    (E) If the feedback speed is stable, use the mean feedback speed
over the recording period as the measured speed for this operating
point.
    (F) If the feedback speed is not stable because of the engine,
determine the mean as the value representing the midpoint between the
observed maximum and minimum recorded feedback speed.
    (G) If the mean feedback torque over the recording period is within
(0 1)% of Tmaxmapped, use the measured speed for
this operating point as the warm high-idle speed. Otherwise, continue
testing as described in paragraph (b)(6)(ii) of this section.
    (ii) Run a second operating point targeting a positive torque.
Follow the same procedure in paragraphs (b)(6)(i)(A) through (F) of
this section, except that the dynamometer is set to target a torque
equal to the mean feedback torque over the recording period from the
previous operating point plus 20% of Tmax mapped.
    (iii) Use the mean feedback speed and torque values from paragraphs
(b)(6)(i) and (ii) of this section to determine the warm high-idle
speed. If the two recorded speed values are the same, use that value as
the warm high-idle-speed. Otherwise, use a linear equation passing
through these two speed-torque points and extrapolate to solve for the
speed at zero torque and use this speed intercept value as the warm
high-idle speed.
    (iv) You may use a manufacturer-declared Tmax instead of
the measured Tmax mapped. If you do this, you may also
measure the warm high-idle speed as described in this paragraph (b)(6)
before running the operating point and speed sweeps specified in
paragraphs (b)(4) and (5) of this section.
* * * * *
    (c) * * *
    (2) Map the amount of negative torque required to motor the engine
by repeating paragraph (b) of this section with minimum operator
demand, as applicable. You may start the negative torque map at either
the minimum or maximum speed from paragraph (b) of this section.
* * * * *
    (d) Mapping constant-speed engines. Map constant-speed engines
using the procedure in this paragraph (d). When testing without a
motoring dynamometer (e.g., eddy-current or water-brake dynamometer or
any device that is already installed on a vehicle, equipment, or
vessel) operate these devices over the no-load operating points in the
procedure as close to no-load as possible.
* * * * *
    (4) With the governor or simulated governor controlling speed using
operator demand, operate the engine at the no-load, or minimum
achievable load, governed speed (at high speed, not low idle) for at
least 15 seconds.
    (5) * * *
    (iii) For any isochronous governed (0% speed droop) constant-speed
engine, you may map the engine with two points as described in this
paragraph (d)(5)(iii). After stabilizing at the no-load, or minimum
achievable load, governed speed in paragraph (d)(4) of this section,
record the mean feedback speed and torque. Continue to operate the
engine with the governor or simulated governor controlling engine speed
using operator demand, and control the dynamometer to target a speed of
99.5% of the recorded mean no-load governed speed. Allow speed and
torque to stabilize. Record the mean feedback speed and torque. Record
the target speed. The absolute value of the speed error (the mean
feedback speed minus the target speed) must be no greater than 0.1% of
the recorded mean no-load governed speed. From this series of two mean
feedback speed and torque values, use linear interpolation to determine
intermediate values. Use this series of two mean feedback speeds and
torques to generate a power map as described in paragraph (e) of this
section. Note that the measured maximum test torque as determined in
Sec.  1065.610(b)(1) will be the mean feedback torque recorded on the
second point.
* * * * *
    (g) * * *
    (2) The purpose of the mapping procedure in this paragraph (g) is
to determine the maximum torque available at each speed, such as what
might occur during transient operation with a fully charged RESS. Use
one of the following methods to generate a hybrid-active map:
    (i) Perform an engine map by using a series of continuous sweeps to
cover the engine's full range of operating speeds. Prepare the engine
for hybrid-active mapping by ensuring that the RESS state of charge is
representative of normal operation. Perform the sweep as specified in
paragraph (b)(5)(i) of this section, but stop the sweep to charge the
RESS when the power measured from the RESS drops below the expected
maximum power from the RESS by more than 2% of total system power
(including engine and RESS power). Unless good engineering judgment
indicates otherwise, assume that the expected maximum power from the
RESS is equal to the measured RESS power at the start of the sweep
segment. For example, if the 3-second rolling average of total engine-
RESS power is 200 kW and the power from the RESS at the beginning of
the sweep segment is 50 kW, once the power from the RESS reaches 46 kW,
stop the sweep to charge the RESS. Note that this assumption is not
valid where the hybrid motor is torque-limited. Calculate total system
power as a 3-second rolling average of instantaneous total system
power. After each charging event, stabilize the engine for 15 seconds
at the speed at which you ended the previous segment with operator
demand set to maximum before continuing the sweep from that speed.
Repeat the cycle of charging, mapping, and recharging until you have
completed the engine map. You may shut down the system or include other
operation between segments to be consistent with the intent of this
paragraph (g)(2)(i). For example, for systems in which continuous
charging and discharging can overheat batteries to an extent that
affects performance, you may operate the engine at zero power from the
RESS for enough time after the system is recharged to allow the
batteries to cool. Use good engineering judgment to smooth the torque
curve to eliminate discontinuities between map intervals.

    (ii) Perform an engine map by using discrete speeds. Select map
setpoints at intervals defined by the ranges of engine speed being
mapped. From 95% of warm idle speed to 90% of the expected maximum test
speed, select setpoints that result in a minimum of 13 equally spaced
speed setpoints. From 90% to 110% of expected maximum test speed,
select setpoints in equally spaced intervals that are nominally 2% of
expected maximum test speed. Above 110% of expected maximum test speed,
select setpoints based on the same speed intervals used for mapping
from 95% warm idle speed to 90% maximum test speed. You may stop
mapping at the highest speed above maximum power at which 50% of
maximum power occurs. We refer to the speed at 50% power as the check
point speed as described in paragraph (b)(5)(iii) of this section.
Stabilize engine speed at each setpoint, targeting a torque value at
70% of peak torque at that speed without hybrid-assist. Make sure the
engine is fully warmed up and the RESS state of charge is within the
normal operating range. Snap the operator demand to maximum, operate
the engine there for at least 10 seconds, and record the 3-second
rolling average feedback speed and torque at 1 Hz or higher. Record the
peak 3-second average torque and 3-second average speed at that point.
Use linear interpolation to determine intermediate speeds and torques.
Follow Sec.  1065.610(a) to calculate the maximum test speed. Verify
that the measured maximum test speed falls in the range from 92 to 108%
of the estimated maximum test speed. If the measured maximum test speed
does not fall in this range, repeat the map using the measured value of
maximum test speed.
* * * * *

0
237. Amend Sec.  1065.512 by revising paragraph (b)(1) to read as
follows:

Sec.  1065.512  Duty cycle generation.

* * * * *
    (b) * * *
    (1) Engine speed for variable-speed engines. For variable-speed
engines, normalized speed may be expressed as a percentage between warm
idle speed, fnidle, and maximum test speed,
fntest, or speed may be expressed by referring to a defined
speed by name, such as ``warm idle,'' ``intermediate speed,'' or ``A,''
``B,'' or ``C'' speed. Section 1065.610 describes how to transform
these normalized values into a sequence of reference speeds,
fnref. Running duty cycles with negative or small normalized
speed values near warm idle speed may cause low-speed idle governors to
activate and the engine torque to exceed the reference torque even
though the operator demand is at a minimum. In such cases, we recommend
controlling the dynamometer so it gives priority to follow the
reference torque instead of the reference speed and let the engine
govern the speed. Note that the cycle-validation criteria in Sec.
1065.514 allow an engine to govern itself. This allowance permits you
to test engines with enhanced-idle devices and to simulate the effects
of transmissions such as automatic transmissions. For example, an
enhanced-idle device might be an idle speed value that is normally
commanded only under cold-start conditions to quickly warm up the
engine and aftertreatment devices. In this case, negative and very low
normalized speeds will generate reference speeds below this higher
enhanced-idle speed. You may do either of the following when using
enhanced-idle devices:
    (i) Control the dynamometer so it gives priority to follow the
reference torque, controlling the operator demand so it gives priority
to follow reference speed and let the engine govern the speed when the
operator demand is at minimum.
    (ii) While running an engine where the ECM broadcasts an enhanced-
idle speed that is above the denormalized speed, use the broadcast
speed as the reference speed. Use these new reference points for duty-
cycle validation. This does not affect how you determine denormalized
reference torque in paragraph (b)(2) of this section.
    (iii) If an ECM broadcast signal is not available, perform one or
more practice cycles to determine the enhanced-idle speed as a function
of cycle time. Generate the reference cycle as you normally would but
replace any reference speed that is lower than the enhanced-idle speed
with the enhanced-idle speed. This does not affect how you determine
denormalized reference torque in paragraph (b)(2) of this section.
* * * * *

0
238. Amend Sec.  1065.514 by revising paragraph (d) to read as follows

Sec.  1065.514  Cycle-validation criteria for operation over specified
duty cycles.

* * * * *
    (d) Omitting additional points. Besides engine cranking, you may
omit additional points from cycle-validation statistics as described in
the following table:

Table 1 to Paragraph (d) of Sec.   1065.514--Permissible Criteria for Omitting Points From Duty-Cycle Regression
                                                   Statistics
----------------------------------------------------------------------------------------------------------------
 When operator demand is at its . .
                 .                        you may omit . . .                         if . . .
----------------------------------------------------------------------------------------------------------------
                For reference duty cycles that are specified in terms of speed and torque (f, T)
----------------------------------------------------------------------------------------------------------------
minimum............................  power and torque...........  Tref < 0% (motoring).
minimum............................  power and speed............  fnref = 0% (idle speed) and Tref = 0% (idle
                                                                   torque) and Tref-(2% [middot] Tmax mapped) <
                                                                   T < Tref + (2% [middot] Tmax mapped).
minimum............................  power and speed............  fnref < enhanced-idle speed \a\ and Tref > 0%.
minimum............................  power and either torque or   fn > fnref or T > Tref but not if fn > (fnref
                                      speed.                       [middot] 102%) and T > Tref + (2% [middot]
                                                                   Tmax mapped).
maximum............................  power and either torque or   fn < fnref or T < Tref but not if fn < (fnref
                                      speed.                       [middot] 98%) and T < Tref-(2% [middot] Tmax
                                                                   mapped).
----------------------------------------------------------------------------------------------------------------
                 For reference duty cycles that are specified in terms of speed and power (f, P)
----------------------------------------------------------------------------------------------------------------
minimum............................  power and torque...........  Pref < 0% (motoring).
minimum............................  power and speed............  fnref = 0% (idle speed) and Pref = 0% (idle
                                                                   power) and Pref-(2% [middot] Pmax mapped) < P
                                                                   < Pref + (2% [middot] Pmax mapped).
minimum............................  power and either torque or   fn > fnref or P > Pref but not if fn > (fnref
                                      speed.                       [middot] 102%) and P > Pref + (2% [middot]
                                                                   Pmax mapped).
maximum............................  power and either torque or   fn < fnref or P < Pref but not if fn < (fnref
                                      speed.                       [middot] 98%) and P < Pref-(2% [middot] Pmax
                                                                   mapped).
----------------------------------------------------------------------------------------------------------------
\a\ Determine enhanced-idle speed from ECM broadcast or a practice cycle.

* * * * *

0
239. Amend Sec.  1065.530 by revising paragraph (g)(5) introductory
text to read as follows:

Sec.  1065.530  Emission test sequence.

* * * * *
    (g) * * *
    (5) If you perform the optional carbon balance error verification,
verify carbon balance error as specified in the standard-setting part
and Sec.  1065.543. Calculate and report the three carbon balance error
quantities for each test interval; carbon mass absolute error for a
test interval, [epsi]aC, carbon mass rate
absolute error for a test interval, [epsi]aCrate,
and carbon mass relative error for a test interval,
[epsi]rC. For duty cycles with multiple test
intervals, you may calculate and report the composite carbon mass
relative error, [epsi]rCcomp, for the whole duty
cycle. If you report [epsi]rCcomp, you must still
calculate and report [epsi]aC,
[epsi]aCrate, and [epsi]rC
for each test interval.
* * * * *

0
240. Amend Sec.  1065.543 by revising paragraphs (a) and (b) to read as
follows:

Sec.  1065.543  Carbon balance error verification.

    (a) This optional carbon balance error verification compares
independently calculated quantities of carbon flowing into and out of
an engine system. The engine system includes aftertreatment devices as
applicable. Calculating carbon intake considers carbon-carrying streams
flowing into the system, including intake air, fuel, and optionally DEF
or other fluids. Carbon flow out of the system comes from exhaust
emission calculations. Note that this verification is not valid if you
calculate exhaust molar flow rate using fuel rate and chemical balance
as described in Sec.  1065.655(f)(3) because carbon flows into and out
of the system are not independent. Use good engineering judgment to
ensure that carbon mass in and carbon mass out data signals align.
    (b) Perform the carbon balance error verification after emission
sampling is complete for a test sequence as described in Sec.
1065.530(g)(5). Testing must include measured values as needed to
determine intake air, fuel flow, and carbon-related gaseous exhaust
emissions. You may optionally account for the flow of carbon-carrying
fluids other than intake air and fuel into the system. Perform carbon
balance error verification as follows:
    (1) Calculate carbon balance error quantities as described in Sec.
1065.643. The three quantities for individual test intervals are carbon
mass absolute error, [epsi]aC, carbon mass rate
absolute error, [epsi]aCrate, and carbon mass
relative error, [epsi]rC. Determine
[epsi]aC, [epsi]aCrate, and
[epsi]rC for all test intervals. You may
determine composite carbon mass relative error,
[epsi]rCcomp, as a fourth quantity that
optionally applies for duty cycles with multiple test intervals.
    (2) You meet the carbon balance error verification for a test
sequence if all test intervals pass the test-interval criteria. A test
interval passes if at least one of the absolute values of the three
carbon balance error quantities for test intervals,
[epsi]aC, [epsi]aCrate, and
[epsi]rC, is at or below its respective limit
value in paragraphs (b)(2)(i) through (iii) of this section. You meet
the carbon balance error verification for a duty cycle with multiple
test intervals if the duty cycle passes the duty-cycle criterion. A
duty cycle passes if the absolute value of the composite carbon mass
relative error quantity, [epsi]rCcomp, is at or
below the limit value in paragraph (b)(2)(iii) of this section. Unless
specified otherwise in the standard-setting part, if verification fails
for a test sequence, you may repeat the entire test sequence or repeat
individual test intervals as described in Sec.  1065.526.
    (i) Calculate the carbon mass absolute error limit,
L[egr]aC, in grams to three decimal places for comparison to
the absolute value of [epsi]aC, using the following
equation:
[GRAPHIC] [TIFF OMITTED] TR24JA23.104

Where:

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

Example:

c = 0.007 g/kW
Pmax = 230.0 kW
L[egr]aC = 0.007 [middot] 230.0
L[egr]aC = 1.610 g

    (ii) Calculate the carbon mass rate absolute error limit,
L[egr]aCrate, in grams per hour to three decimal places for comparison
to the absolute value of [epsi]aCrate, using the
following equation:
[GRAPHIC] [TIFF OMITTED] TR24JA23.105

Where:

d = power-specific carbon mass rate absolute error coefficient =
0.31 g/(kW[middot]hr).
Pmax = maximum power from the engine map generated
according to Sec.  1065.510. If measured Pmax is not
available, use a manufacturer-declared value for Pmax.

Example:

d = 0.31 g/(kW[middot]hr)
Pmax = 230.0 kW
L[egr]aCrate = <IP_ADDRESS>
L[egr]aCrate = 71.300 g/hr

    (iii) The carbon mass relative error limit, L[epsi]rC,
is 0.020 for comparison to the absolute value of
[epsi]rC, and to the absolute value of
[epsi]rCcomp.
* * * * *

0
241. Amend Sec.  1065.545 by revising paragraphs (a) and (b)
introductory text to read as follows:

Sec.  1065.545  Verification of proportional flow control for batch
sampling.

* * * * *
    (a) For any pair of sample and total flow rates, use continuous
recorded data or 1 Hz means. Total flow rate means the raw exhaust flow
rate for raw exhaust sampling and the dilute exhaust flow rate for CVS
sampling. For each test interval, determine the standard error of the
estimate, SEE, of the sample flow rate versus the total flow rate as
described in Sec.  1065.602, forcing the intercept to zero. Determine
the mean sample flow rate over each test interval as described in Sec.
1065.602. For each test interval, demonstrate that SEE is at or below
3.5% of the mean sample flow rate.
    (b) For any pair of sample and total flow rates, use continuous
recorded data or 1 Hz means. Total flow rate means the raw exhaust flow
rate for raw exhaust sampling and the dilute exhaust flow rate for CVS
sampling. For each test interval, demonstrate that each flow rate is
constant within 2.5% of its respective mean or target flow
rate. You may use the following options instead of recording the
respective flow rate of each type of meter:
* * * * *

0
242. Amend Sec.  1065.610 by:
0
a. Revising the introductory text, paragraphs (a) introductory text,
(a)(1) introductory text, and (a)(3).
0
b. Removing paragraph (a)(4).
0
c. Revising paragraphs (b) introductory text, (b)(1) introductory text,
(b)(2) and (3), and (c)(2).

    The revisions read as follows:

Sec.  1065.610  Duty cycle generation.

    This section describes how to generate duty cycles that are
specific to your engine, based on the normalized duty cycles in the
standard-setting part. During an emission test, use a duty cycle that
is specific to your engine to command engine speed, torque, and power,
as applicable, using an engine dynamometer and an engine operator
demand. Paragraphs (a) and (b) of this section describe how to
``normalize'' your engine's map to determine the maximum test speed or
torque for your

engine. The rest of this section describes how to use these values to
``denormalize'' the duty cycles in the standard-setting parts, which
are all published on a normalized basis. Thus, the term ``normalized''
in paragraphs (a) and (b) of this section refers to different values
than it does in the rest of the section.
    (a) Maximum test speed, [fnof]ntest. For variable-speed engines,
determine [fnof]ntest from the torque and power maps,
generated according to Sec.  1065.510, as follows:
    (1) Determine a measured value for [fnof]ntest as
follows:
* * * * *
    (3) Transform normalized speeds to reference speeds according to
paragraph (c) of this section by using the measured maximum test speed
determined according to paragraphs (a)(1) and (2) of this section--or
use your declared maximum test speed, as allowed in Sec.  1065.510.
    (b) Maximum test torque, Ttest. For constant-speed engines,
determine Ttest from the torque and power-versus-speed maps,
generated according to Sec.  1065.510, as follows:
    (1) For constant speed engines mapped using the methods in Sec.
1065.510(d)(5)(i) or (ii), determine a measured value for
Ttest as follows:
* * * * *
    (2) For constant speed engines using the two-point mapping method
in Sec.  1065.510(d)(5)(iii), you may follow paragraph (a)(1) of this
section to determine the measured Ttest, or you may use the
measured torque of the second point as the measured Ttest
directly.
    (3) Transform normalized torques to reference torques according to
paragraph (d) of this section by using the measured maximum test torque
determined according to paragraph (b)(1) or (2) of this section--or use
your declared maximum test torque, as allowed in Sec.  1065.510.
    (c) * * *
    (2) A, B, C, and D speeds. If your normalized duty cycle specifies
speeds as A, B, C, or D values, use your power-versus-speed curve to
determine the lowest speed below maximum power at which 50% of maximum
power occurs. Denote this value as nlo. Take nlo
to be warm idle speed if all power points at speeds below the maximum
power speed are higher than 50% of maximum power. Also determine the
highest speed above maximum power at which 70% of maximum power occurs.
Denote this value as nhi. If all power points at speeds
above the maximum power speed are higher than 70% of maximum power,
take nhi to be the declared maximum safe engine speed or the
declared maximum representative engine speed, whichever is lower. Use
nhi and nlo to calculate reference values for A,
B, C, or D speeds as follows:
[GRAPHIC] [TIFF OMITTED] TR24JA23.106

Example:

nlo = 1005 r/min
nhi = 2385 r/min
[fnof]nrefA = 0.25 [middot] (2385 - 1005) + 1005
[fnof]nrefB = 0.50 [middot] (2385 - 1005) + 1005
[fnof]nrefC = 0.75 [middot] (2385 - 1005) + 1005
[fnof]nrefD = 0.15 [middot] (2385 - 1005) + 1005
[fnof]nrefA = 1350 r/min
[fnof]nrefB = 1695 r/min
[fnof]nrefC = 2040 r/min
[fnof]nrefD = 1212 r/min
* * * * *

0
243. Amend Sec.  1065.630 by revising paragraphs (a) and (b)
introductory text to read as follows:

Sec.  1065.630  Local acceleration of gravity.

    (a) The acceleration of Earth's gravity, ag, varies
depending on the test location. Determine ag at your
location by entering latitude, longitude, and elevation data into the
U.S. National Oceanographic and Atmospheric Administration's surface
gravity prediction website at https://geodesy.noaa.gov/cgi-bin/grav_pdx.prl.
    (b) If the website specified in paragraph (a) of this section is
unavailable, or the test location is outside of the continental United
States, you may calculate ag for your latitude as follows:
* * * * *

0
244. Amend Sec.  1065.643 by revising paragraph (d) to read as follows:

Sec.  1065.643  Carbon balance error verification calculations.

* * * * *
    (d) Carbon balance error quantities. Calculate carbon balance error
quantities as follows:
    (1) Calculate carbon mass absolute error, [epsi]aC, for
a test interval as follows:
[GRAPHIC] [TIFF OMITTED] TR24JA23.107

Where:

mCexh = mass of carbon in exhaust emissions over the test
interval as determined in paragraph (d) of this section.
mCfluid = mass of carbon in all the carbon-carrying fluid
streams flowing into the system over the test interval as determined
in paragraph (a) of this section.
mCair = mass of carbon in the intake air flowing into the
system over the test interval as determined in paragraph (b) of this
section.

Example:

mCexh = 1247.2 g
mCfluid = 975.3 g
mCair = 278.6 g
[epsi]aC = 1247.2 - 975.3 - 278.6
[epsi]aC = -6.7 g

    (2) Calculate carbon mass rate absolute error,
[epsi]aCrate, for a test interval as follows:
[GRAPHIC] [TIFF OMITTED] TR24JA23.108

Where:

t = duration of the test interval.

Example:

[epsi]aC = -6.7 g
    t = 1202.2 s = 0.3339 hr
    [GRAPHIC] [TIFF OMITTED] TR24JA23.109

[epsi]aCrate = -20.065 g/hr

    (3) Calculate carbon mass relative error, [epsi]rC, for
a test interval as follows:
[GRAPHIC] [TIFF OMITTED] TR24JA23.110

Example:

[epsi]aC = -6.7 g
mCfluid = 975.3 g
mCair = 278.6 g
[GRAPHIC] [TIFF OMITTED] TR24JA23.111

[epsi]rC = -0.0053

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

[GRAPHIC] [TIFF OMITTED] TR24JA23.112

Where:

i = an indexing variable that represents one test interval.
N = number of test intervals.
WF = weighting factor for the test interval as defined in the
standard-setting part.
mCexh = mass of carbon in exhaust emissions over the test
interval as determined in paragraph (c) of this section.
mCfluid = mass of carbon in all the carbon-carrying fluid
streams that flowed into the system over the test interval as
determined in paragraph (a) of this section.
mCair = mass of carbon in the intake air that flowed into
the system over the test interval as determined in paragraph (b) of
this section.
t = duration of the test interval. For duty cycles with multiple
test intervals of a prescribed duration, such as cold-start and hot-
start transient cycles, set t = 1 for all test intervals. For
discrete-mode steady-state duty cycles with multiple test intervals
of varying duration, set t equal to the actual duration of each test
interval.

    (ii) The following example illustrates calculation of
[epsi]rCcomp, for cold-start and hot-start transient cycles:

N = 2
WF1 = \1/7\
WF2 = \6/7\
mCexh1 = 1255.3 g
mCexh2 = 1247.2 g
mCfluid1 = 977.8 g
mCfluid2 = 975.3 g
mCair1 = 280.2 g
mCair2 = 278.6 g
[GRAPHIC] [TIFF OMITTED] TR24JA23.113

[epsi]rCcomp = -0.0049

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

N = 2
WF1 = 0.85
WF2 = 0.15
mCexh1 = 2.873 g
mCexh2 = 0.125 g
mCfluid1 = 2.864 g
mCfluid2 = 0.095 g
mCair1 = 0.023 g
mCair2 = 0.024 g
t1 = 123 s
t2 = 306 s
[GRAPHIC] [TIFF OMITTED] TR24JA23.114

[epsi]rCcomp = -0.0047

0
245. Amend Sec.  1065.650 by revising paragraphs (a), (c)(2)(i),
(c)(3), (c)(4)(i), (c)(6), (d)(7), (e)(1) and (2), (f)(1) and (2), and
(g)(1) and (2) to read as follows:

Sec.  1065.650  Emission calculations.

    (a) General. Calculate brake-specific emissions over each
applicable duty cycle or test interval. For test intervals with zero
work (or power), calculate the emission mass (or mass rate), but do not
calculate brake-specific emissions. Unless specified otherwise, for the
purposes of calculating and reporting emission mass (or mass rate), do
not alter any negative values of measured or calculated quantities. You
may truncate negative values in chemical balance quantities listed in
Sec.  1065.655(c) to facilitate convergence. For duty cycles with
multiple test intervals, refer to the standard-setting part for
calculations you need to determine a composite result, such as a
calculation that weights and sums the results of individual test
intervals in a duty cycle. If the standard-setting part does not
include those calculations, use the equations in paragraph (g) of this
section. This section is written based on rectangular integration,
where each indexed value (i.e., ``i'') represents (or
approximates) the mean value of the parameter for its respective time
interval, delta-t. You may also integrate continuous signals using
trapezoidal integration consistent with good engineering judgment.
* * * * *
    (c) * * *
    (2) * * *
    (i) Varying flow rate. If you continuously sample from a varying
exhaust flow rate, time align and then multiply concentration
measurements by the flow rate from which you extracted it. We consider
the following to be examples of varying flows that require a continuous
multiplication of concentration times molar flow rate: raw exhaust,
exhaust diluted with a constant flow rate of dilution air, and CVS
dilution with a CVS flow meter that does not have an upstream heat
exchanger or electronic flow control. This multiplication results in
the flow rate of the emission itself. Integrate the emission flow rate
over a test interval to determine the total emission. If the total
emission is a molar quantity, convert this quantity to a mass by
multiplying it by its molar mass, M. The result is the mass of the
emission, m. Calculate m for continuous sampling with variable flow
using the following equations:
[GRAPHIC] [TIFF OMITTED] TR24JA23.115

Where:

[GRAPHIC] [TIFF OMITTED] TR24JA23.116

Example:

MNMHC = 13.875389 g/mol
N = 1200
xNMHC1 = 84.5 [micro]mol/mol = 84.5 [middot]
10-\6\ mol/mol
xNMHC2 = 86.0 [micro]mol/mol = 86.0 [middot]
10-\6\ mol/mol
nexh1 = 2.876 mol/s
nexh2 = 2.224 mol/s
[fnof]record = 1 Hz

    Using Eq. 1065.650-5,

[Delta]t = 1/1 = 1 s
mNMHC = 13.875389 [middot] (84.5 [middot] 10-\6\
[middot] 2.876 + 86.0 [middot] 10-\6\ [middot] 2.224 + . . .
+ xNMHC1200 [middot] nexh) [middot] 1
mNMHC = 25.23 g
* * * * *
    (3) Batch sampling. For batch sampling, the concentration is a
single value from a proportionally extracted batch sample (such as a
bag, filter, impinger, or cartridge). In this case, multiply the mean
concentration of the batch sample by the total flow from which the
sample was extracted. You may calculate total flow by integrating a
varying flow rate or by determining the mean of a constant flow rate,
as follows:
    (i) Varying flow rate. If you collect a batch sample from a varying
exhaust flow rate, extract a sample proportional to the varying exhaust
flow rate. We consider the following to be examples of varying flows
that require proportional sampling: raw exhaust, exhaust diluted with a
constant flow rate of dilution air, and CVS dilution with a CVS flow
meter that does not have an upstream heat exchanger or electronic flow
control. Integrate the flow rate over a test interval to determine the
total flow from which you extracted the proportional sample. Multiply
the mean concentration of the batch sample by the total flow from which
the sample was extracted to determine the total emission. If the total
emission is a molar quantity, convert this quantity to a mass by
multiplying it by its molar mass, M. The result is the total emission
mass, m. In the case of PM emissions, where the mean PM concentration
is already in units of mass per mole of exhaust, simply multiply it by
the total flow. The result is the total mass of PM, mPM.
Calculate m for each constituent as follows:
    (A) Calculate m for measuring gaseous emission constituents with
sampling that results in a molar concentration, x, using the following
equation:
[GRAPHIC] [TIFF OMITTED] TR24JA23.117

Example:

MNOX = 46.0055 g/mol
N = 9000
x = 85.6 [micro]mol/mol = 85.6 [middot] 10-\6\ mol/mol
ndexh1 = 25.534 mol/s
ndexh2 = 26.950 mol/s
[fnof]record = 5 Hz

    Using Eq. 1065.650-5:

[Delta]t = 1/5 = 0.2 s
mNOX 46.0055 [middot] 85.6 [middot] 10-\6\
[middot] (25.534 + 26.950+ . . . +
nexh9000) [middot] 0.2
mNOX = 4.201 g
    (B) Calculate m for sampling PM or any other analysis of a batch
sample that yields a mass per mole of exhaust, M, using the following
equation:
[GRAPHIC] [TIFF OMITTED] TR24JA23.118

    (ii) Proportional or constant flow rate. If you batch sample from a
constant exhaust flow rate, extract a sample at a proportional or
constant flow rate. We consider the following to be examples of
constant exhaust flows: CVS diluted exhaust with a CVS flow meter that
has either an upstream heat exchanger, electronic flow control, or
both. Determine the mean molar flow rate from which you extracted the
sample. Multiply the mean concentration of the batch sample by the mean
molar flow rate of the exhaust from which the sample was extracted to
determine the total emission and multiply the result by the time of the
test interval. If the total emission is a molar quantity, convert this
quantity to a mass by multiplying it by its molar mass, M. The result
is the total emission mass, m. In the case of PM emissions, where the
mean PM concentration is already in units of mass per mole of exhaust,
simply multiply it by the total flow, and the result is the total mass
of PM, mPM. Calculate m for each constituent as follows:
    (A) Calculate m for measuring gaseous emission constituents with
sampling that results in a molar concentration, x, using the following
equation:
[GRAPHIC] [TIFF OMITTED] TR24JA23.119

    (B) Calculate m for sampling PM or any other analysis of a batch
sample that yields a mass per mole of exhaust, M, using the following
equation:
[GRAPHIC] [TIFF OMITTED] TR24JA23.120

    (C) The following example illustrates a calculation of
mPM:

MPM = 144.0 [micro]g/mol = 144.0 [middot] 10-\6\
g/mol
nidexh = 57.692 mol/s
[Delta]t = 1200 s
mPM = 144.0 [middot] 10-\6\ [middot] 57.692
[middot] 1200
mPM = 9.9692 g

    (4) * * *
    (i) For sampling with a constant dilution ratio, DR, of diluted
exhaust versus exhaust flow (e.g., secondary dilution for PM sampling),
calculate m using the following equation:
[GRAPHIC] [TIFF OMITTED] TR24JA23.121

Example:

mPMdil = 6.853 g
DR = 6:1
mPM = 6.853 [middot] 6
mPM = 41.118 g
* * * * *
    (6) Mass of NMNEHC. Determine the mass of NMNEHC using one of the
following methods:
    (i) If the test fuel has less than 0.010 mol/mol of ethane and you
omit the NMNEHC calculations as described in Sec.  1065.660(c)(1), take
the corrected mass of NMNEHC to be 0.95 times the corrected mass of
NMHC.
    (ii) If the test fuel has at least 0.010 mol/mol of ethane and you
omit the NMNEHC calculations as described in Sec.  1065.660(c)(1), take
the corrected mass of NMNEHC to be 1.0 times the corrected mass of
NMHC.
    (d) * * *
    (7) Integrate the resulting values for power over the test
interval. Calculate total work as follows:
[GRAPHIC] [TIFF OMITTED] TR24JA23.122

Where:

W = total work from the primary output shaft.
Pi = instantaneous power from the primary output shaft over an
interval i.
[GRAPHIC] [TIFF OMITTED] TR24JA23.123

Example:

N = 9000
[fnof]n1 = 1800.2 r/min
[fnof]n2 = 1805.8 r/min
T1 = 177.23 N[middot]m

T2 = 175.00 N[middot]m
Crev = 2[middot][pi] rad/r
Ct1 = 60 s/min
Cp = 1000 (N[middot]m[middot]rad/s)/kW
[fnof]record = 5 Hz
Ct2 = 3600 s/hr
[GRAPHIC] [TIFF OMITTED] TR24JA23.124

P1 = 33.41 kW
P2 = 33.09 kW

    Using Eq. 1065.650-5:

[Delta]t = 1/5 = 0.2 s
[GRAPHIC] [TIFF OMITTED] TR24JA23.125

W = 16.875 kW[middot]hr

* * * * *
    (e) * * *
    (1) To calculate, mi, multiply its mean concentration, x, by its
corresponding mean molar flow rate, ni. If the result is a molar flow
rate, convert this quantity to a mass rate by multiplying it by its
molar mass, M. The result is the mean mass rate of the emission, mi. In
the case of PM emissions, where the mean PM concentration is already in
units of mass per mole of exhaust, simply multiply it by the mean molar
flow rate, ni. The result is the mass rate of PM, mPM.
Calculate mi using the following equation:
[GRAPHIC] [TIFF OMITTED] TR24JA23.126

    (2) To calculate an engine's mean steady-state total power, P, add
the mean steady-state power from all the work paths described in Sec.
1065.210 that cross the system boundary including electrical power,
mechanical shaft power, and fluid pumping power. For all work paths,
except the engine's primary output shaft (crankshaft), the mean steady-
state power over the test interval is the integration of the net work
flow rate (power) out of the system boundary divided by the period of
the test interval. When power flows into the system boundary, the
power/work flow rate signal becomes negative; in this case, include
these negative power/work rate values in the integration to calculate
the mean power from that work path. Some work paths may result in a
negative mean power. Include negative mean power values from any work
path in the mean total power from the engine rather than setting these
values to zero. The rest of this paragraph (e)(2) describes how to
calculate the mean power from the engine's primary output shaft.
Calculate P using Eq. 1065.650-13, noting that P, fn, and T
refer to mean power, mean rotational shaft frequency, and mean torque
from the primary output shaft. Account for the power of simulated
accessories according to Sec.  1065.110 (reducing the mean primary
output shaft power or torque by the accessory power or torque). Set the
power to zero during actual motoring operation (negative feedback
torques), unless the engine was connected to one or more energy storage
devices. Examples of such energy storage devices include hybrid
powertrain batteries and hydraulic accumulators, like the ones denoted
``Acc.'' and ``Batt.'' as illustrated in Figure 1 of Sec.  1065.210.
Set the power to zero for modes with a zero reference load (0
N[middot]m reference torque or 0 kW reference power). Include power
during idle modes with simulated minimum torque or power.
[GRAPHIC] [TIFF OMITTED] TR24JA23.127

* * * * *
    (f) * * *
    (1) Total mass. To determine a value proportional to the total mass
of an emission, determine total mass as described in paragraph (c) of
this section, except substitute for the molar flow rate, n, or the
total flow, n, with a signal that is linearly proportional to molar
flow rate, n, or linearly proportional to total flow, n, as follows:
[GRAPHIC] [TIFF OMITTED] TR24JA23.128

    (2) Total work. To calculate a value proportional to total work
over a test interval, integrate a value that is proportional to power.
Use information about the brake-specific fuel consumption of your
engine, efuel, to convert a signal proportional to fuel flow
rate to a signal proportional to power. To determine a signal
proportional to fuel flow rate, divide a signal that is proportional to
the mass rate of carbon products by the fraction of carbon in your
fuel, wC. You may use a measured wC or you may
use default values for a given fuel as described in Sec.  1065.655(e).
Calculate the mass rate of carbon from the amount of carbon and water
in the exhaust, which you determine with a chemical balance of fuel,
DEF, intake air, and exhaust as described in Sec.  1065.655. In the
chemical balance, you must use concentrations from the flow that
generated the signal proportional to molar flow rate, ni, in paragraph
(e)(1) of this section. Calculate a value proportional to total work as
follows:
[GRAPHIC] [TIFF OMITTED] TR24JA23.129

Where:
[GRAPHIC] [TIFF OMITTED] TR24JA23.130

* * * * *
    (g) * * *
    (1) Use the following equation to calculate composite brake-
specific emissions for duty cycles with multiple test intervals all
with prescribed durations, such as cold-start and hot-start transient
cycles:
[GRAPHIC] [TIFF OMITTED] TR24JA23.131

Where:

i = test interval number.
N = number of test intervals.
WF = weighting factor for the test interval as defined in the
standard-setting part.

m = mass of emissions over the test interval as determined in
paragraph (c) of this section.
W = total work from the engine over the test interval as determined
in paragraph (d) of this section.

Example:

N = 2
WF1 = 0.1428
WF2 = 0.8572
m1 = 70.125 g
m2 = 64.975 g
W1 = 25.783 kW[middot]hr
W2 = 25.783 kW[middot]hr
[GRAPHIC] [TIFF OMITTED] TR24JA23.132

eNOxcomp = 2.548 g/kW[middot]hr

    (2) Calculate composite brake-specific emissions for duty cycles
with multiple test intervals that allow use of varying duration, such
as discrete-mode steady-state duty cycles, as follows:
    (i) Use the following equation if you calculate brake-specific
emissions over test intervals based on total mass and total work as
described in paragraph (b)(1) of this section:
[GRAPHIC] [TIFF OMITTED] TR24JA23.133

Where:

i = test interval number.
N = number of test intervals.
WF = weighting factor for the test interval as defined in the
standard-setting part.
m = mass of emissions over the test interval as determined in
paragraph (c) of this section.
W = total work from the engine over the test interval as determined
in paragraph (d) of this section.
t = duration of the test interval.

Example:

N = 2
WF1 = 0.85
WF2 = 0.15
m1 = 1.3753 g
m2 = 0.4135 g
t1 = 120 s
t2 = 200 s
W1 = 2.8375 kW [middot] hr
W2 = 0.0 kW [middot] hr
[GRAPHIC] [TIFF OMITTED] TR24JA23.134

eNOxcomp = 0.5001 g/kW[middot]hr

    (ii) Use the following equation if you calculate brake-specific
emissions over test intervals based on the ratio of mass rate to power
as described in paragraph (b)(2) of this section:
[GRAPHIC] [TIFF OMITTED] TR24JA23.135

Where:

i = test interval number.
N = number of test intervals.
WF = weighting factor for the test interval as defined in the
standard-setting part.
mi = mean steady-state mass rate of emissions over the test interval
as determined in paragraph (e) of this section.
p = mean steady-state power over the test interval as described in
paragraph (e) of this section.

Example:

N = 2
WF1 = 0.85
WF2 = 0.15
mi1 = 2.25842 g/hr
mi2 = 0.063443 g/hr
P1 = 4.5383 kW
P2 = 0.0 kW
[GRAPHIC] [TIFF OMITTED] TR24JA23.136

eNOxcomp = 0.5001 g/kW[middot]hr
* * * * *

0
246. Amend Sec.  1065.655 by revising paragraphs (c) introductory text,
(e)(1)(i), (e)(4), and (f)(3) to read as follows:

Sec.  1065.655  Chemical balances of fuel, DEF, intake air, and
exhaust.

* * * * *
    (c) Chemical balance procedure. The calculations for a chemical
balance involve a system of equations that require iteration. We
recommend using a computer to solve this system of equations. You must
guess the initial values of up to three quantities: the amount of water
in the measured flow, xH2Oexh, fraction of dilution air in
diluted exhaust, xdil/exh, and the amount of products on a
C1 basis per dry mole of dry measured flow,
xCcombdry. You may use time-weighted mean values of intake
air humidity and dilution air humidity in the chemical balance; as long
as your intake air and dilution air humidities remain within tolerances
of 0.0025 mol/mol of their respective mean values over the
test interval. For each emission concentration, x, and amount of water,
xH2Oexh, you must determine their completely dry
concentrations, xdry and xH2Oexhdry. You must
also use your fuel mixture's atomic hydrogen-to-carbon ratio, [alpha],
oxygen-to-carbon ratio, [beta], sulfur-to-carbon ratio, [gamma], and
nitrogen-to-carbon ratio, [delta]; you may optionally account for
diesel exhaust fluid (or other fluids injected into the exhaust), if
applicable. You may calculate [alpha], [beta], [gamma], and [delta]
based on measured fuel composition or based on measured fuel and diesel
exhaust fluid (or other fluids injected into the exhaust) composition
together, as

described in paragraph (e) of this section. You may alternatively use
any combination of default values and measured values as described in
paragraph (e) of this section. Use the following steps to complete a
chemical balance:
* * * * *
    (e) * * *
    (1) * * *
    (i) Determine the carbon and hydrogen mass fractions according to
ASTM D5291 (incorporated by reference in Sec.  1065.1010). When using
ASTM D5291 to determine carbon and hydrogen mass fractions of gasoline
(with or without blended ethanol), use good engineering judgment to
adapt the method as appropriate. This may include consulting with the
instrument manufacturer on how to test high-volatility fuels. Allow the
weight of volatile fuel samples to stabilize for 20 minutes before
starting the analysis; if the weight still drifts after 20 minutes,
prepare a new sample). Retest the sample if the carbon, hydrogen,
oxygen, sulfur, and nitrogen mass fractions do not add up to a total
mass of 100 0.5%; you may assume oxygen has a zero mass
contribution for this specification for diesel fuel and neat (E0)
gasoline. You may also assume that sulfur and nitrogen have a zero mass
contribution for this specification for all fuels except residual fuel
blends.
* * * * *
    (4) Calculate [alpha], [beta], [gamma], and [delta] using the
following equations:
[GRAPHIC] [TIFF OMITTED] TR24JA23.137

Where:

N = total number of fuels and injected fluids over the duty cycle.
j = an indexing variable that represents one fuel or injected fluid,
starting with j = 1.
mj = the mass flow rate of the fuel or any injected fluid j. For
applications using a single fuel and no DEF fluid, set this value to
1. For batch measurements, divide the total mass of fuel over the
test interval duration to determine a mass rate.
wHj = hydrogen mass fraction of fuel or any injected
fluid j.
wCj = carbon mass fraction of fuel or any injected fluid
j.
wOj = oxygen mass fraction of fuel or any injected fluid
j.
wSj = sulfur mass fraction of fuel or any injected fluid
j.
wNj = nitrogen mass fraction of fuel or any injected
fluid j.

Example:

N = 1
j = 1
m1 = 1
wH1 = 0.1239
wC1 = 0.8206
    wO1 = 0.0547
    wS1 = 0.00066
    wN1 = 0.000095
    MC = 12.0107 g/mol
    MH = 1.00794 g/mol
    MO = 15.9994 g/mol
    MS = 32.065 g/mol
    MN = 14.0067
    [GRAPHIC] [TIFF OMITTED] TR24JA23.138

[alpha] = 1.799
[beta] = 0.05004
[gamma] = 0.0003012
[delta] = 0.0001003
* * * * *
    (f) * * *
    (3) Fluid mass flow rate calculation. This calculation may be used
only for steady-state laboratory testing. You may not use this
calculation if the standard-setting part requires carbon balance error
verification as described in Sec.  1065.543. See Sec.
1065.915(d)(5)(iv) for application to field testing. Calculate
nexh based on mj using the following equation:
[GRAPHIC] [TIFF OMITTED] TR24JA23.139

Where:

nexh = raw exhaust molar flow rate from which you
measured emissions.
j = an indexing variable that represents one fuel or injected fluid,
starting with j = 1.
N = total number of fuels and injected fluids over the duty cycle.
mj = the mass flow rate of the fuel or any injected fluid j.
wCj = carbon mass fraction of the fuel and any injected
fluid j.

Example:

N = 1
j = 1
m1 = 7.559 g/s
wC1 = 0.869 g/g
MC = 12.0107 g/mol
xCcombdry1 = 99.87 mmol/mol = 0.09987 mol/mol
xH20exhdry1 = 107.64 mmol/mol = 0.10764 mol/mol
[GRAPHIC] [TIFF OMITTED] TR24JA23.140

nexh = 6.066 mol/s
* * * * *

0
247. Amend Sec.  1065.660 by revising paragraphs (b)(2)(i) introductory
text, (c)(1), and (d)(1)(i) introductory text to read as follows:

Sec.  1065.660  THC, NMHC, NMNEHC, CH4, and C2H6 determination.

* * * * *
    (b) * * *
    (2) * * *
    (i) If you need to account for penetration fractions determined as
a function of molar water concentration, use Eq. 1065.660-4. Otherwise,
use the following equation for penetration fractions determined using
an NMC configuration as outlined in Sec.  1065.365(d):
* * * * *
    (c) * * *
    (1) Calculate xNMNEHC based on the test fuel's ethane
content as follows:
    (i) If the content of your test fuel contains less than 0.010 mol/
mol of ethane, you may omit the calculation of NMNEHC concentration and
calculate the mass of NMNEHC as described in Sec.  1065.650(c)(6)(i).
    (ii) If the content of your fuel test contains at least 0.010 mol/
mol of ethane, you may omit the calculation of NMNEHC concentration and
calculate the mass of NMNEHC as described in Sec.  1065.650(c)(6)(ii).
* * * * *
    (d) * * *
    (1) * * *
    (i) If you need to account for penetration fractions determined as
a function of molar water concentration, use Eq. 1065.660-11.
Otherwise, use the following equation for penetration fractions
determined using an NMC configuration as outlined in Sec.  1065.365(d):
* * * * *

0
248. Amend Sec.  1065.667 by revising paragraph (a) to read as follows:

Sec.  1065.667  Dilution air background emission correction.

    (a) To determine the mass of background emissions to subtract from
a diluted exhaust sample, first determine the total flow of dilution
air, ndil, over the test interval. This may be a measured
quantity or a calculated quantity. Multiply the total flow of dilution
air by the mean mole fraction (i.e., concentration) of a background
emission. This may be a time-weighted mean or a flow-weighted mean
(e.g., a proportionally sampled background). Finally, multiply by the
molar mass, M, of the associated gaseous emission constituent. The
product of ndil and the mean molar concentration of a
background emission and its molar mass, M, is the total background
emission mass, m. In the case of PM, where the mean PM concentration is
already in units of mass per mole of exhaust, multiply it by the total
amount of dilution air flow, and the result is the total background
mass of PM, mPM. Subtract total background mass from total
mass to correct for background emissions.
* * * * *

0
249. Amend Sec.  1065.670 by revising the introductory text to read as
follows:

Sec.  1065.670  NOX intake-air humidity and temperature corrections.

    See the standard-setting part to determine if you may correct
NOX emissions for the effects of intake-air humidity or
temperature. Use the NOX intake-air humidity and temperature
corrections specified in the standard-setting part instead of the
NOX intake-air humidity correction specified in this part
1065. If the standard-setting part does not prohibit correcting
NOX emissions for intake-air humidity according to this part
1065, correct NOX concentrations for intake-air humidity as
described in this section. See Sec.  1065.650(c)(1) for the proper
sequence for applying the NOX intake-air humidity and
temperature corrections. You may use a time-weighted mean intake air
humidity to calculate this correction if your intake air humidity
remains within a tolerance of 0.0025 mol/mol of the mean
value over the test interval. For intake-air humidity correction, use
one of the following approaches:
* * * * *

0
250. Amend Sec.  1065.672 by revising paragraphs (d)(3) and (4) to read
as follows:

Sec.  1065.672  Drift correction.

* * * * *
    (d) * * *
    (3) For any pre-test interval concentrations, use the last
concentration determined before the test interval. For some test
intervals, the last pre-zero or pre-span might have occurred before one
or more earlier test intervals.
    (4) For any post-test interval concentrations, use the first
concentration determined after the test interval. For some test
intervals, the first post-zero or post-span might occur after one or
more later test intervals.
* * * * *

0
251. Amend Sec.  1065.675 by revising paragraph (b) to read as follows:

Sec.  1065.675  CLD quench verification calculations.

* * * * *
    (b) Estimate the maximum expected mole fraction of water during
emission testing, xH2Oexp. Make this estimate where the
humidified NO span gas was introduced in Sec.  1065.370(e)(6). When
estimating the maximum expected mole fraction of water, consider the
maximum expected water content in intake air, fuel combustion products,
and dilution air (if applicable). If you introduced the humidified NO
span gas into the sample system upstream of a sample dryer during the
verification test, you need not estimate the maximum expected mole
fraction of water and you must set xH2Oexp equal to
xH2Omeas.
* * * * *

0
252. Amend Sec.  1065.680 by revising the introductory text to read as
follows:

Sec.  1065.680  Adjusting emission levels to account for infrequently
regenerating aftertreatment devices.

    This section describes how to calculate and apply emission
adjustment factors for engines using aftertreatment technology with
infrequent regeneration events that may occur during testing. These
adjustment factors are typically calculated based on measurements
conducted for the purposes of engine certification, and then used to
adjust the results of testing related to demonstrating compliance with
emission standards. For this section, ``regeneration'' means an
intended event during which emission levels change while the system
restores aftertreatment performance. For example, exhaust gas
temperatures may increase temporarily to remove sulfur from an adsorber
or SCR catalyst or to oxidize accumulated particulate matter in a trap.
The duration of this event extends until the aftertreatment performance
and emission levels have returned to normal baseline levels. Also,
``infrequent'' refers to regeneration events that are expected to occur
on average less than once over a transient or ramped-modal duty cycle,
or on average less than once per mode in a discrete-mode test.
* * * * *

0
253. Amend Sec.  1065.695 by revising paragraphs (a) and (c)(12)(ix) to
read as follows:

Sec.  1065.695  Data requirements.

    (a) To determine the information we require from engine tests,
refer to the standard-setting part and request from your EPA Program
Officer the format used to apply for certification or demonstrate
compliance. We may require different information for different
purposes, such as for certification applications, approval requests for
alternate procedures, selective enforcement audits, laboratory audits,
production-line test reports, and field-test reports.
* * * * *
    (c) * * *
    (12) * * *
    (ix) Warm idle speed value, any enhanced-idle speed value.
* * * * *

0
254. Amend Sec.  1065.715 by revising paragraph (b)(3) to read as
follows:

Sec.  1065.715  Natural gas.

* * * * *
    (b) * * *
    (3) You may ask for approval to use fuel that does not meet the
specifications in paragraph (a) of this section, but only if using the
fuel would not adversely affect your ability to demonstrate compliance
with the applicable standards in this chapter.
* * * * *

0
255. Amend Sec.  1065.720 by revising paragraphs (a) and (b)(3) to read
as follows:

Sec.  1065.720  Liquefied petroleum gas.

    (a) Except as specified in paragraph (b) of this section, liquefied
petroleum gas for testing must meet the specifications in the following
table:

  Table 1 to Paragraph (a) of Sec.   1065.720--Test Fuel Specifications
                       for Liquefied Petroleum Gas
------------------------------------------------------------------------
                                                           Reference
            Property                     Value           procedure \a\
------------------------------------------------------------------------
Propane, CH.....................  Minimum, 0.85 m\3\/ ASTM D2163.
                                   m\3\.
Vapor pressure at 38[deg]C......  Maximum, 1400 kPa.  ASTM D1267 or
                                                      ASTM D2598 \b\.
Butanes.........................  Maximum, 0.05 m\3\/ ASTM D2163.
                                   m\3\.
Butenes.........................  Maximum, 0.02 m     ASTM D2163.
                                   \3\/m \3\.
Pentenes and heavier............  Maximum, 0.005 m    ASTM D2163.
                                   \3\/m\3\.
Propene.........................  Maximum, 0.1 m \3\/ ASTM D2163.
                                   m\3\.
Residual matter (residue on       Maximum, 0.05 ml    ASTM D2158.
 evaporation of 100 ml oil stain   pass \c\.
 observation).
Corrosion, copper strip.........  Maximum, No. 1....  ASTM D1838.
Sulfur..........................  Maximum, 80 mg/kg.  ASTM D6667.
Moisture content................  pass..............  ASTM D2713.
------------------------------------------------------------------------
\a\ Incorporated by reference; see Sec.   1065.1010. See Sec.
  1065.701(d) for other allowed procedures.
\b\ If these two test methods yield different results, use the results
  from ASTM D1267.
\c\ The test fuel must not yield a persistent oil ring when you add 0.3
  ml of solvent residue mixture to a filter paper in 0.1 ml increments
  and examine it in daylight after two minutes.

    (b) * * *
    (3) You may ask for approval to use fuel that does not meet the
specifications in paragraph (a) of this section, but only if using the
fuel would not adversely affect your ability to demonstrate compliance
with the applicable standards in this chapter.
* * * * *

0
256. Revise Sec.  1065.790 to read as follows:

Sec.  1065.790  Mass standards.

    (a) PM balance calibration weights. Use PM balance calibration
weights that are certified as NIST-traceable within 0.1%
uncertainty. Make sure your highest calibration weight has no more than
ten times the mass of an unused PM-sample medium.
    (b) Dynamometer, fuel mass scale, and DEF mass scale calibration
weights. Use dynamometer and mass scale calibration weights that are
certified as NIST-traceable within 0.1% uncertainty.

0
257. Amend Sec.  1065.901 by revising paragraphs (a) and (b)(3) to read
as follows:

Sec.  1065.901  Applicability.

    (a) Field testing. This subpart specifies procedures for field-
testing engines to determine brake-specific emissions and mass rate
emissions using portable emission measurement systems (PEMS). These
procedures are designed primarily for in-field measurements of engines
that remain installed in vehicles or equipment the field. Field-test
procedures apply to your engines only as specified in the standard-
setting part.
    (b) * * *
    (3) Do not use PEMS for laboratory measurements if it prevents you
from demonstrating compliance with the applicable standards in this
chapter. Some of the PEMS requirements in this part 1065 are less
stringent than the corresponding laboratory requirements. Depending on
actual PEMS performance, you might therefore need to account for some
additional measurement uncertainty when using PEMS for laboratory
testing. If we ask, you must show us by engineering analysis that any
additional measurement uncertainty due to your use of PEMS for
laboratory testing is

offset by the extent to which your engine's emissions are below the
applicable standards in this chapter. For example, you might show that
PEMS versus laboratory uncertainty represents 5% of the standard, but
your engine's deteriorated emissions are at least 20% below the
standard for each pollutant.

0
258. Amend Sec.  1065.910 by revising paragraphs (b) and (d)(2) to read
as follows:

Sec.  1065.910  PEMS auxiliary equipment for field testing.

* * * * *
    (b) Locate the PEMS to minimize the effects of the following
parameters or place the PEMS in an environmental enclosure that
minimizes the effect of these parameters on the emission measurement:
    (1) Ambient temperature changes.
    (2) Electromagnetic radiation.
    (3) Mechanical shock and vibration.
* * * * *
    (d) * * *
    (2) You may install your own portable power supply. For example,
you may use batteries, fuel cells, a portable generator, or any other
power supply to supplement or replace your use of vehicle power. You
may connect an external power source directly to the vehicle's,
vessel's, or equipment's power system; however, you must not supply
power to the vehicle's power system in excess of 1% of the engine's
maximum power.

0
259. Amend Sec.  1065.915 by revising paragraph (d)(6) to read as
follows:

Sec.  1065.915  PEMS instruments.

* * * * *
    (d) * * *
    (6) Permissible deviations. ECM signals may deviate from the
specifications of this part 1065, but the expected deviation must not
prevent you from demonstrating that you meet the applicable standards
in this chapter. For example, your emission results may be sufficiently
below an applicable standard, such that the deviation would not
significantly change the result. As another example, a very low engine-
coolant temperature may define a logical statement that determines when
a test interval may start. In this case, even if the ECM's sensor for
detecting coolant temperature was not very accurate or repeatable, its
output would never deviate so far as to significantly affect when a
test interval may start.

0
260. Amend Sec.  1065.920 by:
0
a. Revising paragraphs (b)(2), (b)(4) introductory text, and
(b)(4)(iii).
0
b. Removing paragraph (b)(5).
0
c. Redesignating paragraphs (b)(6) and (7) as (b)(5) and (6),
respectively.
0
d. Revising newly redesignated paragraph (b)(6)(ii).

    The revisions read as follows:

Sec.  1065.920  PEMS calibrations and verifications.

* * * * *
    (b) * * *
    (2) Select or create a duty cycle that has all the following
characteristics:
    (i) Engine operation that represents normal in-use speeds, loads,
and degree of transient activity. Consider using data from previous
field tests to generate a cycle.
    (ii) A duration of (6 to 9) hours.
* * * * *
    (4) Determine the brake-specific emissions and mass rate emissions,
as applicable, for each test interval for both laboratory and the PEMS
measurements, as follows:
* * * * *
    (iii) If the standard-setting part specifies the use of a
measurement allowance for field testing, also apply the measurement
allowance during calibration using good engineering judgment. If the
measurement allowance is normally added to the standard, this means you
must subtract the measurement allowance from measured PEMS emission
results.
* * * * *
    (6) * * *
    (ii) The entire set of test-interval results passes the 95%
confidence alternate-procedure statistics for field testing (t-test and
F-test) specified in Sec.  1065.12.

0
261. Amend Sec.  1065.935 by revising paragraphs (d)(4) and (g) to read
as follows:

Sec.  1065.935  Emission test sequence for field testing.

* * * * *
    (d) * * *
    (4) Conduct periodic verifications such as zero and span
verifications on PEMS gas analyzers and use these to correct for drift
according to paragraph (g) of this section. Do not include data
recorded during verifications in emission calculations. Conduct the
verifications as follows:
    (i) For PEMS gas analyzers used to determine NTE emission values,
perform verifications as recommended by the PEMS manufacturer or as
indicated by good engineering judgment.
    (ii) For PEMS gas analyzers used to determine bin emission values,
perform zero verifications at least hourly using purified air. Perform
span verification at the end of the shift-day or more frequently as
recommended by the PEMS manufacturer or as indicated by good
engineering judgment.
* * * * *
    (g) Take the following steps after emission sampling is complete:
    (1) As soon as practical after emission sampling, analyze any
gaseous batch samples.
    (2) If you used dilution air, either analyze background samples or
assume that background emissions were zero. Refer to Sec.  1065.140 for
dilution-air specifications.
    (3) After quantifying all exhaust gases, record mean analyzer
values after stabilizing a zero gas to each analyzer, then record mean
analyzer values after stabilizing the span gas to the analyzer.
Stabilization may include time to purge an analyzer of any sample gas
and any additional time to account for analyzer response. Use these
recorded values, including pre-test verifications and any zero
verifications during testing, to correct for drift as described in
Sec.  1065.550.
    (4) Verify PEMS gas analyzers used to determine NTE emission values
as follows:
    (i) Invalidate any data that does not meet the range criteria in
Sec.  1065.550. Note that it is acceptable that analyzers exceed 100%
of their ranges when measuring emissions between test intervals, but
not during test intervals. You do not have to retest an engine if the
range criteria are not met.
    (ii) Invalidate any data that does not meet the drift criterion in
Sec.  1065.550. For HC, invalidate any data if the difference between
the uncorrected and the corrected brake-specific HC emission values are
not within 10% of the uncorrected results or the applicable
standard, whichever is greater. For data that does meet the drift
criterion, correct those test intervals for drift according to Sec.
1065.672 and use the drift corrected results in emissions calculations.
    (5) Verify PEMS gas analyzers used to determine bin emission values
as follows:
    (i) Invalidate data from a whole shift-day if more than 1% of
recorded 1 Hz data exceeds 100% of the selected gas analyzer range. For
analyzer outputs exceeding 100% of range, calculate emission results
using the reported value. You must retest an engine if the range
criteria are not met.
    (ii) Invalidate any data for periods in which the CO and
CO2 gas analyzers do not meet the drift criterion in Sec.
1065.550. For HC, invalidate data if the difference between the
uncorrected and the corrected brake-specific HC emission values are not
within 10% of the uncorrected results or the applicable

standard, whichever is greater. For data that do meet the drift
criterion, correct the data for drift according to Sec.  1065.672 and
use the drift-corrected results in emissions calculations.
    (iii) For PEMS NOX analyzers used to determine bin
emission values, invalidate data for the engine over the entire shift-
day if any data do not meet the following drift limits instead of
meeting the drift criteria specified in Sec.  1065.550:
    (A) The allowable analyzer zero-drift between successive zero
verifications is 2.5 ppm. The analyzer zero-drift limit
over the shift-day is 10 ppm.
    (B) The allowable analyzer span-drift limit is 4% of
the measured span value between successive span verifications.
    (6) Unless you weighed PM in-situ, such as by using an inertial PM
balance, place any used PM samples into covered or sealed containers
and return them to the PM-stabilization environment and weigh them as
described in Sec.  1065.595.

0
262. Amend Sec.  1065.1001 by:
0
a. Removing the definition of ``Designated Compliance Officer''.
0
b. Adding definitions of ``Dual-fuel'', ``EPA Program Officer'', and
``Flexible-fuel'' in alphabetical order.
0
c. Removing the definition of ``Intermediate test speed''.
0
d. Adding a definition of ``Intermediate speed'' in alphabetical order.
0
e. Revising the definition of ``NIST-traceable''.
0
f. Adding definitions of ``No-load'' and ``Rechargeable Energy Storage
System (RESS)'' in alphabetical order.
0
g. Revising the definition of ``Steady-state''.

    The additions and revisions read as follows:

Sec.  1065.1001  Definitions.

* * * * *
    Dual-fuel has the meaning given in the standard-setting part.
* * * * *
    EPA Program Officer means the Director, Compliance Division, U.S.
Environmental Protection Agency, 2000 Traverwood Dr., Ann Arbor, MI
48105.
* * * * *
    Flexible-fuel has the meaning given in the standard-setting part.
* * * * *
    Intermediate speed has the meaning given in Sec.  1065.610.
* * * * *
    NIST-traceable means relating to a standard value that can be
related to NIST-stated references through an unbroken chain of
comparisons, all having stated uncertainties, as specified in NIST
Technical Note 1297 (incorporated by reference in Sec.  1065.1010).
Allowable uncertainty limits specified for NIST-traceability refer to
the propagated uncertainty specified by NIST.
* * * * *
    No-load means a dynamometer setting of zero torque.
* * * * *
    Rechargeable Energy Storage System (RESS) means the components of a
hybrid engine or vehicle that store recovered energy for later use,
such as the battery system in a hybrid electric vehicle.
* * * * *
    Steady-state means relating to emission tests in which engine speed
and load are held at a finite set of nominally constant values. Steady-
state tests are generally either discrete-mode tests or ramped-modal
tests.
* * * * *

0
263. Amend Sec.  1065.1005 by adding an entry in Table 1 in paragraph
(a) for ``[kappa]'' in alphanumeric order and revising paragraphs (b)
and (f)(1), (3), and (4) to read as follows:

Sec.  1065.1005  Symbols, abbreviations, acronyms, and units of
measure.

* * * * *
    (a) * * *

                               Table 1 of Sec.   1065.1005--Symbols for Quantities
----------------------------------------------------------------------------------------------------------------
                                                                                Units in terms of
             Symbol                    Quantity              Unit             Unit Symbol        SI base units
----------------------------------------------------------------------------------------------------------------

                                                  * * * * * * *
[kappa].........................  opacity

                                                  * * * * * * *
----------------------------------------------------------------------------------------------------------------

* * * * *
    (b) Symbols for chemical species. This part uses the following
symbols for chemical species and exhaust constituents:

  Table 2 of Sec.   1065.1005--Symbols for Chemical Species and Exhaust
                              Constituents
------------------------------------------------------------------------
                 Symbol                              Species
------------------------------------------------------------------------
Ar.....................................  argon.
C......................................  carbon.
CH2O...................................  formaldehyde.
CH2O2..................................  formic acid.
CH3OH..................................  methanol.
CH4....................................  methane.
C2H4O..................................  acetaldehyde.
C2H5OH.................................  ethanol.
C2H6...................................  ethane.
C3H7OH.................................  propanol.
C3H8...................................  propane.
C4H10..................................  butane.
C5H12..................................  pentane.
CO.....................................  carbon monoxide.
CO2....................................  carbon dioxide.

H......................................  atomic hydrogen.
H2.....................................  molecular hydrogen.
H2O....................................  water.
H2SO4..................................  sulfuric acid.
HC.....................................  hydrocarbon.
He.....................................  helium.
\85\Kr.................................  krypton 85.
N2.....................................  molecular nitrogen.
NH3....................................  ammonia.
NMHC...................................  nonmethane hydrocarbon.
NMHCE..................................  nonmethane hydrocarbon
                                          equivalent.
NMNEHC.................................  nonmethane-nonethane
                                          hydrocarbon.
NO.....................................  nitric oxide.
NO2....................................  nitrogen dioxide.
NOX....................................  oxides of nitrogen.
N2O....................................  nitrous oxide.
NMOG...................................  nonmethane organic gases.
NONMHC.................................  non-oxygenated nonmethane
                                          hydrocarbon.
NOTHC..................................  non-oxygenated total
                                          hydrocarbon.
O2.....................................  molecular oxygen.
OHC....................................  oxygenated hydrocarbon.
\210\Po................................  polonium 210.
PM.....................................  particulate matter.
S......................................  sulfur.
SVOC...................................  semi-volatile organic compound.
THC....................................  total hydrocarbon.
THCE...................................  total hydrocarbon equivalent.
ZrO2...................................  zirconium dioxide.
------------------------------------------------------------------------

* * * * *
    (f) * * *
    (1) This part uses the following constants for the composition of
dry air:

                 Table 6 of Sec.   1065.1005--Constants
------------------------------------------------------------------------
           Symbol                    Quantity               mol/mol
------------------------------------------------------------------------
[gamma]Arair...............  amount of argon in dry              0.00934
                              air.
[gamma]CO2air..............  amount of carbon                   0.000375
                              dioxide in dry air.
[gamma]N2air...............  amount of nitrogen in               0.78084
                              dry air.
[gamma]O2air...............  amount of oxygen in dry            0.209445
                              air.
------------------------------------------------------------------------

* * * * *
    (3) This part uses the following molar gas constant for ideal
gases:

     Table 8 of Sec.   1065.1005--Molar Gas Constant for Ideal Gases
------------------------------------------------------------------------
                                                    J/(mol[middot]K)
                                               (m\2\[middot]kg[middot]s-
         Symbol                Quantity             \2\[middot]mol-
                                                   \1\[middot]K-\1\)
------------------------------------------------------------------------
R......................  molar gas constant..                8.314472
------------------------------------------------------------------------

    (4) This part uses the following ratios of specific heats for
dilution air and diluted exhaust:

 Table 9 of Sec.   1065.1005--Ratios of Specific Heats for Dilution Air
                           and Diluted Exhaust
------------------------------------------------------------------------
                                                      [J/(kg[middot]K)]/
           Symbol                    Quantity          [J/(kg[middot]K)]
------------------------------------------------------------------------
[gamma]air.................  ratio of specific heats               1.399
                              for intake air or
                              dilution air.
[gamma]dil.................  ratio of specific heats               1.399
                              for diluted exhaust.
[gamma]exh.................  ratio of specific heats               1.385
                              for raw exhaust.
------------------------------------------------------------------------

* * * * *

0
264. Amend Sec.  1065.1010 by:
0
a. Adding introductory text;

0
b. Removing paragraph (a); and
0
c. Redesignating paragraphs (b) through (g) as paragraphs (a) through
(f).

    The addition reads as follows:

Sec.  1065.1010  Incorporation by reference.

    Certain material is incorporated by reference into this part with
the approval of the Director of the Federal Register under 5 U.S.C.
552(a) and 1 CFR part 51. To enforce any edition other than that
specified in this section, EPA must publish a document in the Federal
Register and the material must be available to the public. All approved
incorporation by reference (IBR) material is available for inspection
at EPA and at the National Archives and Records Administration (NARA).
Contact EPA at: U.S. EPA, Air and Radiation Docket Center, WJC West
Building, Room 3334, 1301 Constitution Ave. NW, Washington, DC 20004;
www.epa.gov/dockets;<PHONE_NUMBER>. For information on inspecting this
material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations.html or email [email protected]. The material may be
obtained from the following sources:
* * * * *

0
265. Revise the heading for subpart L to read as follows:

Subpart L--Methods for Unregulated and Special Pollutants and
Additional Procedures

0
266. Amend subpart L by adding a new center header ``VANADIUM
SUBLIMATION IN SCR CATALYSTS'' after Sec.  1065.1111 and adding
Sec. Sec.  1065.1113, 1065.1115, 1065.1117, 1065.1119, and 1065.1121
under the new center header to read as follows:

Vanadium Sublimation In SCR Catalysts

Sec.  1065.1113  General provisions related to vanadium sublimation
temperatures in SCR catalysts.

    Sections 1065.1113 through 1065.1121 specify procedures for
determining vanadium emissions from a catalyst based on catalyst
temperature. Vanadium can be emitted from the surface of SCR catalysts
at temperatures above 550[deg]C, dependent on the catalyst formulation.
These procedures are appropriate for measuring the vanadium sublimation
product from a reactor by sampling onto an equivalent mass of alumina
and performing analysis by Inductively Coupled Plasma--Optical Emission
Spectroscopy (ICP-OES). Follow standard analytic chemistry methods for
any aspects of the analysis that are not specified.
    (a) The procedure is adapted from ``Behavior of Titania-supported
Vanadia and Tungsta SCR Catalysts at High Temperatures in Reactant
Streams: Tungsten and Vanadium Oxide and Hydroxide Vapor Pressure
Reduction by Surficial Stabilization'' (Chapman, D.M., Applied
Catalysis A: General, 2011, 392, 143-150) with modifications to the
acid digestion method from ``Measuring the trace elemental composition
of size-resolved airborne particles'' (Herner, J.D. et al,
Environmental Science and Technology, 2006, 40, 1925-1933).
    (b) Laboratory cleanliness is especially important throughout
vanadium testing. Thoroughly clean all sampling system components and
glassware before testing to avoid sample contamination.

Sec.  1065.1115  Reactor design and setup.

    Vanadium measurements rely on a reactor that adsorbs sublimation
vapors of vanadium onto an alumina capture bed with high surface area.
    (a) Configure the reactor with the alumina capture bed downstream
of the catalyst in the reactor's hot zone to adsorb vanadium vapors at
high temperature. You may use quartz beads upstream of the catalyst to
help stabilize reactor gas temperatures. Select an alumina material and
design the reactor to minimize sintering of the alumina. For a 1-inch
diameter reactor, use 4 to 5 g of \1/8\ inch extrudates or -14/+24 mesh
(approximately 0.7 to 1.4 mm) gamma alumina (such as Alfa Aesar,
aluminum oxide, gamma, catalyst support, high surface area, bimodal).
Position the alumina downstream from either an equivalent amount of -
14/+24 mesh catalyst sample or an approximately 1-inch diameter by 1 to
3-inch long catalyst-coated monolith sample cored from the production-
intent vanadium catalyst substrate. Separate the alumina from the
catalyst with a 0.2 to 0.4 g plug of quartz wool. Place a short 4 g
plug of quartz wool downstream of the alumina to maintain the position
of that bed. Use good engineering judgment to adjust as appropriate for
reactors of different sizes.
    (b) Include the quartz wool with the capture bed to measure
vanadium content. We recommend analyzing the downstream quartz wool
separately from the alumina to see if the alumina fails to capture some
residual vanadium.
    (c) Configure the reactor such that both the sample and capture
beds are in the reactor's hot zone. Design the reactor to maintain
similar temperatures in the capture bed and catalyst. Monitor the
catalyst and alumina temperatures with Type K thermocouples inserted
into a thermocouple well that is in contact with the catalyst sample
bed.
    (d) If there is a risk that the quartz wool and capture bed are not
able to collect all the vanadium, configure the reactor with an
additional capture bed and quartz wool plug just outside the hot zone
and analyze the additional capture bed and quartz wool separately.
    (e) An example of a catalyst-coated monolith and capture bed
arrangement in the reactor tube are shown in the following figure:

Figure 1 to paragraph (e) of Sec.  1065.1115-- Example of Reactor Setup

[GRAPHIC] [TIFF OMITTED] TR24JA23.141

    (f) You may need to account for vanadium-loaded particles
contaminating catalyst-coated monoliths as a result of physical
abrasion. To do this, determine how much titanium is in the capture bed
and compare to an alumina blank. Using these values and available
information about the ratio of vanadium to titanium in the catalyst,
subtract the mass of vanadium catalyst material associated with the
catalyst particles from the total measured vanadium on the capture bed
to determine the vanadium recovered due to sublimation.

Sec.  1065.1117  Reactor aging cycle for determination of vanadium
sublimation temperature.

    This section describes the conditions and process required to
operate the reactor described in Sec.  1065.1115 for collection of the
vanadium sublimation samples for determination of vanadium sublimation
temperature. The reactor aging cycle constitutes the process of testing
the catalyst sample over all the test conditions described in paragraph
(b) of this section.
    (a) Set up the reactor to flow gases with a space velocity of at
least 35,000/hr with a pressure drop across the catalyst and capture
beds less than 35 kPa. Use test gases meeting the following
specifications, noting that not all gases will be used at the same
time:
    (1) 5 vol% O2, balance N2.
    (2) NO, balance N2. Use an NO concentration of (200 to
500) ppm.
    (3) NH3, balance N2. Use an NH3
concentration of (200 to 500) ppm.
    (b) Perform testing as follows:
    (1) Add a new catalyst sample and capture bed into the reactor as
described in Sec.  1065.1113. Heat the reactor to 550[deg]C while
flowing the oxygen blend specified in paragraph (a)(1) of this section
as a pretest gas mixture. Ensure that no H2O is added to the
pretest gas mixture to reduce the risk of sintering and vanadium
sublimation.
    (2) Start testing at a temperature that is lower than the point at
which vanadium starts to sublime. Start testing when the reactor
reaches 550[deg]C unless testing supports a lower starting temperature.
Once the reactor reaches the starting temperature and the catalyst has
been equilibrated to the reactor temperature, flow NO and
NH3 test gases for 18 hours with a nominal H2O
content of 5 volume percent. If an initial starting temperature of
550[deg]C results in vanadium sublimation, you may retest using a new
catalyst sample and a lower initial starting temperature.
    (3) After 18 hours of exposure, flow the pretest oxygen blend as
specified in paragraph (b)(1) of this section and allow the reactor to
cool down to room temperature.
    (4) Analyze the sample as described in Sec.  1065.1121.
    (5) Repeat the testing in paragraphs (b)(1) through (4) of this
section by raising the reactor temperature in increments of 50[deg]C up
to the temperature at which vanadium sublimation begins.
    (6) Once sublimation has been detected, repeat the testing in
paragraphs (b)(1) through (4) of this section by decreasing the reactor
temperature in increments of 25 [deg]C until the vanadium concentration
falls below the sublimation threshold.
    (7) Repeat the testing in paragraphs (b)(1) through (6) of this
section with a nominal H2O concentration of 10 volume
percent or the maximum water concentration expected at the standard.
    (8) You may optionally test in a manner other than testing a single
catalyst formulation in series across all test temperatures. For
example, you may test additional samples at the same reactor
temperature before moving on to the next temperature.
    (c) The effective sublimation temperature for the tested catalyst
is the lowest reactor temperature determined in paragraph (b) of this
section below which vanadium emissions are less than the method
detection limit.

Sec.  1065.1119  Blank testing.

    This section describes the process for analyzing blanks. Use blanks
to determine the background effects and the potential for contamination
from the sampling process.
    (a) Take blanks from the same batch of alumina used for the capture
bed.
    (b) Media blanks are used to determine if there is any
contamination in the sample media. Analyze at least one media blank for
each reactor aging cycle or round of testing performed under Sec.
1065.1117. If your sample media is taken from the same lot, you may
analyze media blanks less frequently consistent with good engineering
judgment.
    (c) Field blanks are used to determine if there is any
contamination from environmental exposure of the sample media. Analyze
at least one field blank for each reactor aging cycle or round of
testing performed under Sec.  1065.1117. Field blanks must be contained
in a sealed environment and accompany the reactor sampling system
throughout the course of a test, including reactor disassembly, sample
packaging, and

storage. Use good engineering judgment to determine how frequently to
generate field blanks. Keep the field blank sample close to the reactor
during testing.
    (d) Reactor blanks are used to determine if there is any
contamination from the sampling system. Analyze at least one reactor
blank for each reactor aging cycle or round of testing performed under
Sec.  1065.1117.
    (1) Test reactor blanks with the reactor on and operated
identically to that of a catalyst test in Sec.  1065.1117 with the
exception that when loading the reactor, only the alumina capture bed
will be loaded (no catalyst sample is loaded for the reactor blank). We
recommend acquiring reactor blanks with the reactor operating at
average test temperature you used when acquiring your test samples
under Sec.  1065.1117.
    (2) You must run at least three reactor blanks if the result from
the initial blank analysis is above the detection limit of the method,
with additional blank runs based on the uncertainty of the reactor
blank measurements, consistent with good engineering judgment.

Sec.  1065.1121  Vanadium sample dissolution and analysis in alumina
capture beds.

    This section describes the process for dissolution of vanadium from
the vanadium sublimation samples collect in Sec.  1065.1117 and any
blanks collected in Sec.  1065.1119 as well as the analysis of the
digestates to determine the mass of vanadium emitted and the associated
sublimation temperature threshold based on the results of all the
samples taken during the reactor aging cycle.
    (a) Digest the samples using the following procedure, or an
equivalent procedure:
    (1) Place the recovered alumina, a portion of the ground quartz
tube from the reactor, and the quartz wool in a Teflon pressure vessel
with a mixture made from 1.5 mL of 16 N HNO3, 0.5 mL of 28 N
HF, and 0.2 mL of 12 N HCl. Note that the amount of ground quartz tube
from the reactor included in the digestion can influence the vanadium
concentration of both the volatilized vanadium from the sample and the
method detection limit. You must be consistent with the amount ground
quartz tube included in the sample analysis for your testing. You must
limit the amount of quartz tube to include only portions of the tube
that would be likely to encounter volatilized vanadium.
    (2) Program a microwave oven to heat the sample to 180 [deg]C over
9 minutes, followed by a 10-minute hold at that temperature, and 1 hour
of ventilation/cooling.
    (3) After cooling, dilute the digests to 30 mL with high purity
18M[Omega] water prior to ICP-MS (or ICP-OES) analysis. Note that this
digestion technique requires adequate safety measures when working with
HF at high temperature and pressure. To avoid ``carry-over''
contamination, rigorously clean the vessels between samples as
described in ``Microwave digestion procedures for environmental
matrixes'' (Lough, G.C. et al, Analyst. 1998, 123 (7), 103R-133R).
    (b) Analyze the digestates for vanadium as follows:
    (1) Perform the analysis using ICP-OES (or ICP-MS) using standard
plasma conditions (1350 W forward power) and a desolvating
microconcentric nebulizer, which will significantly reduce oxide- and
chloride-based interferences.
    (2) We recommend that you digest and analyze a minimum of three
solid vanadium NIST Standard Reference Materials in duplicate with
every batch of 25 vanadium alumina capture bed samples that you analyze
in this section, as described in ``Emissions of metals associated with
motor vehicle roadways'' (Herner, J.D. et al, Environmental Science and
Technology. 2005, 39, 826-836). This will serve as a quality assurance
check to help gauge the relative uncertainties in each measurement,
specifically if the measurement errors are normally distributed and
independent.
    (3) Use the 3-sigma approach to determine the analytical method
detection limits for vanadium and the 10-sigma approach if you
determine the reporting limit. This process involves analyzing at least
seven replicates of a reactor blank using the analytical method
described in paragraphs (a) and (b)(1) of this section, converting the
responses into concentration units, and calculating the standard
deviation. Determine the detection limit by multiplying the standard
deviation by 3 and adding it to the average. Determine the reporting
limit by multiplying the standard deviation by 10 and adding it to the
average. Determine the following analytical method detection limits:
    (i) Determine the ICP-MS (or ICP-OES) instrumental detection limit
(ng/L) by measuring at least seven blank samples made up of the
reagents from paragraph (a) of this section.
    (ii) Determine the method detection limit ([micro]g/m\3\ of flow)
by measuring at least seven reactor blank samples taken as described in
Sec.  1065.1119(d).
    (iii) We recommend that your method detection limit determined
under paragraph (b)(3)(ii) of this section is at or below 15 [micro]g/
m\3\. You must report your detection limits determined in this
paragraph (b)(3) and reporting limits (if determined) with your test
results.
    (4) If you account for vanadium-loaded particles contaminating
catalyst-coated monoliths as a result of physical abrasion as allowed
in Sec.  1065.1115(f), use the 3-sigma approach to determine the
analytical method detection limits for titanium and the 10-sigma
approach if you determine the reporting limit. This process involves
analyzing at least seven replicates of a blank using the analytical
method described in paragraphs (a) and (b)(1) of this section,
converting the responses into concentration units, and calculating the
standard deviation. Determine the detection limit by multiplying the
standard deviation by 3 and subtracting it from the average. Determine
the reporting limit by multiplying the standard deviation by 10 and
subtracting it from the average.
    (i) Determine the ICP-MS (or ICP-OES) instrumental detection limit
(ng/L) by measuring at least seven blank samples made up of the
reagents from paragraph (a) of this section.
    (ii) Determine the method detection limit ([micro]g/m\3\ of flow)
by measuring at least seven reactor blank samples taken as described in
Sec.  1065.1119(d).

0
267. Amend subpart L by adding a new center header ``SMOKE OPACITY''
after the newly added Sec.  1065.1121 and adding Sec. Sec.  1065.1123,
1065.1125, and 1065.1127 under the new center header to read as
follows:

Smoke Opacity

Sec.  1065.1123  General provisions for determining exhaust opacity.

    The provisions of Sec.  1065.1125 describe system specifications
for measuring percent opacity of exhaust for all types of engines. The
provisions of Sec.  1065.1127 describe how to use such a system to
determine percent opacity of engine exhaust for applications other than
locomotives. See 40 CFR 1033.525 for measurement procedures for
locomotives.

Sec.  1065.1125  Exhaust opacity measurement system.

    Smokemeters measure exhaust opacity using full-flow open-path light
extinction with a built-in light beam across the exhaust stack or
plume. Prepare and install a smokemeter system as follows:
    (a) Except as specified in paragraph (d) of this section, use a
smokemeter capable of providing continuous measurement that meets the
following specifications:
    (1) Use an incandescent lamp with a color temperature between (2800
and 3250) K or a different light source with

a spectral peak between (550 and 570) nm.
    (2) Collimate the light beam to a nominal diameter of 3 centimeters
and maximum divergence angle of 6 degrees.
    (3) Include a photocell or photodiode as a detector. The detector
must have a maximum spectral response between (550 and 570) nm, with
less than 4 percent of that maximum response below 430 nm and above 680
nm. These specifications correspond to visual perception with the human
eye.
    (4) Use a collimating tube with an aperture that matches the
diameter of the light beam. Restrict the detector to viewing within a
16 degree included angle.
    (5) Optionally use an air curtain across the light source and
detector window to minimize deposition of smoke particles, as long as
it does not measurably affect the opacity of the sample.
    (6) The diagram in the following figure illustrates the smokemeter
configuration:

Figure 1 to paragraph (a)(6) of Sec.  1065.1125--Smokemeter Diagram
[GRAPHIC] [TIFF OMITTED] TR24JA23.142

    (b) Smokemeters for locomotive applications must have a full-scale
response time of 0.5 seconds or less. Smokemeters for locomotive
applications may attenuate signal responses with frequencies higher
than 10 Hz with a separate low-pass electronic filter that has the
following performance characteristics:
    (1) Three decibel point: 10 Hz.
    (2) Insertion loss: (0.0 0.5) dB.
    (3) Selectivity: 12 dB down at 40 Hz minimum.
    (4) Attenuation: 27 dB down at 40 Hz minimum.
    (c) Configure exhaust systems as follows for measuring exhaust
opacity:
    (1) For locomotive applications:
    (i) Optionally add a stack extension to the locomotive muffler.
    (ii) For in-line measurements, the smokemeter is integral to the
stack extension.
    (iii) For end-of-line measurements, mount the smokemeter directly
at the end of the stack extension or muffler.
    (iv) For all testing, minimize distance from the optical centerline
to the muffler outlet; in no case may it be more than 300 cm. The
maximum allowable distance of unducted space upstream of the optical
centerline is 50 cm, whether the unducted portion is upstream or
downstream of the stack extensions.
    (2) Meet the following specifications for all other applications:
    (i) For in-line measurements, install the smokemeter in an exhaust
pipe segment downstream of all engine components. This will typically
be part of a laboratory configuration to route the exhaust to an
analyzer. The exhaust pipe diameter must be constant within 3 exhaust
pipe diameters before and after the smokemeter's optical centerline.
The exhaust pipe diameter may not change by more than a 12-degree half-
angle within 6 exhaust pipe diameters upstream of the smokemeter's
optical centerline.
    (ii) For end-of-line measurements with systems that vent exhaust to
the ambient, add a stack extension and position the smokemeter such
that its optical centerline is (2.5 0.625) cm upstream of
the stack extension's exit. Configure the exhaust stack and extension
such that at least the last 60 cm is a straight pipe with a circular
cross section with an approximate inside diameter as specified in the
following table:

Table 1 to Paragraph (c)(2)(ii) of Sec.   1065.1125--Approximate Exhaust
                   Pipe Diameter Based on Engine Power
------------------------------------------------------------------------
                                                            Approximate
                   Maximum rated power                     exhaust pipe
                                                          diameter  (mm)
------------------------------------------------------------------------
kW<40...................................................              38
40<=kW<75...............................................              50
75<=kW<150..............................................              76
150<=kW<225.............................................             102
225<=kW<375.............................................             127
kW= 375......................................             152
------------------------------------------------------------------------

    (iii) For both in-line and end-of-line measurements, install the
smokemeter so its optical centerline is (3 to 10) meters further
downstream than the point in the exhaust stream that is farthest
downstream considering all the following components: exhaust manifolds,
turbocharger outlets, exhaust aftertreatment devices, and junction
points for combining exhaust flow from multiple exhaust manifolds.
    (3) Orient the light beam perpendicular to the direction of exhaust
flow. Install the smokemeter so it does not influence exhaust flow
distribution or the shape of the exhaust plume. Set up the smokemeter's
optical path length as follows:
    (i) For locomotive applications, the optical path length must be at
least as wide as the exhaust plume.
    (ii) For all other applications, the optical path length must be
the same as the diameter of the exhaust flow. For noncircular exhaust
configurations, set up the smokemeter such that the light beam's path
length is across the longest

axis with an optical path length equal to the hydraulic diameter of the
exhaust flow.
    (4) The smokemeter must not interfere with the engine's ability to
meet the exhaust backpressure requirements in Sec.  1065.130(h).
    (5) For engines with multiple exhaust outlets, measure opacity
using one of the following methods:
    (i) Join the exhaust outlets together to form a single flow path
and install the smokemeter (3 to 10) m downstream of the point where
the exhaust streams converge or the last exhaust aftertreatment device,
whichever is farthest downstream.
    (ii) Install a smokemeter in each of the exhaust flow paths. Report
all measured values. All measured values must comply with standards.
    (6) The smokemeter may use purge air or a different method to
prevent carbon or other exhaust deposits on the light source and
detector. Such a method used with end-of-line measurements may not
cause the smoke plume to change by more than 0.5 cm at the smokemeter.
If such a method affects the smokemeter's optical path length, follow
the smokemeter manufacturer's instructions to properly account for that
effect.
    (d) You may use smokemeters meeting alternative specifications as
follows:
    (1) You may use smokemeters that use other electronic or optical
techniques if they employ substantially identical measurement
principles and produce substantially equivalent results.
    (2) You may ask us to approve the use of a smokemeter that relies
on partial flow sampling. Follow the instrument manufacturer's
installation, calibration, operation, and maintenance procedures if we
approve your request. These procedures must include correcting for any
change in the path length of the exhaust plume relative to the diameter
of the engine's exhaust outlet.

Sec.  1065.1127  Test procedure for determining percent opacity.

    The test procedure described in this section applies for everything
other than locomotives. The test consists of a sequence of engine
operating points on an engine dynamometer to measure exhaust opacity
during specific engine operating modes to represent in-use operation.
Measure opacity using the following procedure:
    (a) Use the equipment and procedures specified in this part 1065.
    (b) Calibrate the smokemeter as follows:
    (1) Calibrate using neutral density filters with approximately 10,
20, and 40 percent opacity. Confirm that the opacity values for each of
these reference filters are NIST-traceable within 185 days of testing,
or within 370 days of testing if you consistently protect the reference
filters from light exposure between tests.
    (2) Before each test and optionally during engine idle modes,
remove the smokemeter from the exhaust stream, if applicable, and
calibrate as follows:
    (i) Zero. Adjust the smokemeter to give a zero response when there
is no detectable smoke.
    (ii) Linearity. Insert each of the qualified reference filters in
the light path perpendicular to the axis of the light beam and adjust
the smokemeter to give a result within 1 percentage point of the named
value for each reference filter.
    (c) Prepare the engine, dynamometer, and smokemeter for testing as
follows:
    (1) Set up the engine to run in a configuration that represents in-
use operation.
    (2) Determine the smokemeter's optical path length to the nearest
mm.
    (3) If the smokemeter uses purge air or another method to prevent
deposits on the light source and detector, adjust the system according
to the system manufacturer's instructions and activate the system
before starting the engine.
    (4) Program the dynamometer to operate in torque-control mode
throughout testing. Determine the dynamometer load needed to meet the
cycle requirements in paragraphs (d)(4)(ii) and (iv) of this section.
    (5) You may program the dynamometer to apply motoring assist with
negative flywheel torque, but only during the first 0.5 seconds of the
acceleration events in paragraphs (d)(4)(i) and (ii) of this section.
Negative flywheel torque may not exceed 13.6 N[middot]m.
    (d) Operate the engine and dynamometer over repeated test runs of
the duty cycle illustrated in Figure 1 of this appendix. As noted in
the figure, the test run includes an acceleration mode from points A
through F in the figure, followed by a lugging mode from points I to J.
Detailed specifications for testing apply as follows:
    (1) Continuously record opacity, engine speed, engine torque, and
operator demand over the course of the entire test at 10 Hz; however,
you may interrupt measurements to recalibrate during each idle mode.
    (2) Precondition the engine by operating it for 10 minutes at
maximum mapped power.
    (3) Operate the engine for (5.0 to 5.5) minutes at warm idle speed,
[fnof]nidle, with load set to Curb Idle Transmission Torque.
    (4) Operate the engine and dynamometer as follows during the
acceleration mode:
    (i) First acceleration event--AB. Partially increase and hold
operator demand to stabilize engine speed briefly at (200 50) r/min above [fnof]nidle. The start of this
acceleration is the start of the test (t = 0 s).
    (ii) Second acceleration event--CD. As soon as measured engine
speed is within the range specified in paragraph (d)(4)(i) of this
section, but not more than 3 seconds after the start of the test,
rapidly set and hold operator demand at maximum. Operate the
dynamometer using a preselected load to accelerate engine speed to 85
percent of maximum test speed, [fnof]ntest, in (5 1.5) seconds. The engine speed throughout the acceleration must
be within 100 r/min of a target represented by a linear
transition between the low and high engine speed targets.
    (iii) Transition--DEF. As soon as measured engine speed reaches 85
percent of [fnof]ntest, rapidly set and hold operator demand
at minimum and simultaneously apply a load to decelerate to
intermediate speed in (0.5 to 3.5) seconds. Use the same load
identified for the acceleration event in paragraph (d)(4)(iv) of this
section.
    (iv) Third acceleration event--FGH. Rapidly set and hold operator
demand at maximum when the engine is within 50 r/min of
intermediate speed. Operate the dynamometer using a preselected load to
accelerate engine speed to at least 95 percent of
[fnof]ntest in (10 2) seconds.
    (5) Operate the engine and dynamometer as follows during the
lugging mode:
    (i) Transition--HI. When the engine reaches 95 percent of
[fnof]ntest, keep operator demand at maximum and immediately
set dynamometer load to control the engine at maximum mapped power.
Continue the transition segment for (50 to 60) seconds. For at least
the last 10 seconds of the transition segment, hold engine speed within
50 r/min of [fnof]ntest and power at or above 95
percent of maximum mapped power. Conclude the transition by increasing
dynamometer load to reduce engine speed as specified in paragraph
(d)(4)(iii) of this section, keeping operator demand at maximum.
    (ii) Lugging--IJ. Apply dynamometer loading as needed to decrease
engine speed from 50 r/min below fntest to intermediate
speed in (35 5) seconds. The engine speed must remain
within 100 r/min of a target represented by a

linear transition between the low and high engine speed targets.
    (6) Return the dynamometer and engine controls to the idle position
described in paragraph (d)(3) of this section within 60 seconds of
completing the lugging mode.
    (7) Repeat the procedures in paragraphs (d)(3) through (6) of this
section as needed to complete three valid test runs. If you fail to
meet the specifications during a test run, continue to follow the
specified duty cycle before starting the next test run.
    (8) Shut down the engine or remove the smokemeter from the exhaust
stream to verify zero and linearity. Void the test if the smokemeter
reports more than 2 percent opacity for the zero verification, or if
the smokemeter's error for any of the linearity checks specified in
paragraph (b)(2) of this section is more than 2 percent.
    (e) Analyze and validate the test data as follows:
    (1) Divide each test run into test segments. Each successive test
segment starts when the preceding segment ends. Identify the test
segments based on the following criteria:
    (i) The idle mode specified in paragraph (d)(3) of this section for
the first test run starts immediately after engine preconditioning is
complete. The idle mode for later test runs must start within 60
seconds after the end of the previous test run as specified in
paragraph (d)(6) of this section. The idle mode ends when operator
demand increases for the first acceleration event (Points A and B).
    (ii) The first acceleration event in paragraph (d)(4)(i) of this
section ends when operator demand is set to maximum for the second
acceleration event (Point C).
    (iii) The second acceleration event in paragraph (d)(4)(ii) of this
section ends when the engine reaches 85 percent of maximum test speed,
[fnof]ntest, (Point D) and operator demand is set to minimum
(Point E).
    (iv) The transition period in paragraph (d)(4)(iii) of this section
ends when operator demand is set to maximum (Point F).
    (v) The third acceleration event in paragraph (d)(4)(iv) of this
section ends when engine speed reaches 95 percent of
[fnof]ntest (Point H).
    (vi) The transition period in paragraph (d)(5)(i) of this section
ends when engine speed first decreases to a point more than 50 r/min
below [fnof]ntest (Point I).
    (vii) The lugging mode in paragraph (d)(5)(ii) of this section ends
when the engine reaches intermediate speed (Point J).
    (2) Convert measured instantaneous values to standard opacity
values, [kappa]std, based on the appropriate optical path
length specified in Table 1 of Sec.  1065.1125 using the following
equation:
[GRAPHIC] [TIFF OMITTED] TR24JA23.143

Where:

[kappa]std = standard instantaneous percent opacity.
[kappa]meas = measured instantaneous percent opacity.
lstd = standard optical path length corresponding with
engine power, in millimeters.
lmeas = the smokemeter's optical path length, in
millimeters.

Example for an engine < 40 kW:

[kappa]meas = 14.1%
lstd = 38 mm
lmeas = 41 mm
[GRAPHIC] [TIFF OMITTED] TR24JA23.144

    (3) Select opacity results from corrected measurements collected
across test segments as follows:
    (i) Divide measurements from acceleration and lugging modes into
half-second intervals. Determine average opacity values during each
half-second interval.
    (ii) Identify the 15 highest half-second values during the
acceleration mode of each test run.
    (iii) Identify the five highest half-second values during the
lugging mode of each test run.
    (iv) Identify the three overall highest values from paragraphs
(e)(3)(ii) and (iii) of this section for each test run.
    (f) Determine percent opacity as follows:
    (1) Acceleration. Determine the percent opacity for the
acceleration mode by calculating the average of the 45 readings from
paragraph (e)(3)(ii) of this section.
    (2) Lugging. Determine the percent opacity for the lugging mode by
calculating the average of the 15 readings from paragraph (e)(3)(iii)
of this section.
    (3) Peak. Determine the percent opacity for the peaks in either
acceleration or lugging mode by calculating the average of the 9
readings from paragraph (e)(3)(iv) of this section.
    (g) Submit the following information in addition to what is
required by Sec.  1065.695:
    (1) Exhaust pipe diameter(s).
    (2) Measured maximum exhaust system backpressure over the entire
test.
    (3) Most recent date for establishing that each of the reference
filters from paragraph (b) of this section are NIST-traceable.
    (4) Measured smokemeter zero and linearity values after testing.
    (5) 10 Hz data from all valid test runs.
    (h) The following figure illustrates the dynamometer controls and
engine speeds for exhaust opacity testing:

Figure 1 to paragraph (h) of Sec.  1065.1127--Schemati of Smoke Opacity
Duty Cycle

[GRAPHIC] [TIFF OMITTED] TR24JA23.145

0
268. Amend subpart L by adding a new center header ``ACCELERATED
AFTERTREATMENT AGING'' after the newly added Sec.  1065.1127 and adding
Sec. Sec.  1065.1131 through 1065.1145 under

the new center header to read as follows:

Accelerated Aftertreatment Aging

Sec.  1065.1131  General provisions related to accelerated aging of
compression-ignition aftertreatment for deterioration factor
determination.

    Sections 1065.1131 through 1065.1145 specify procedures for aging
compression-ignition engine aftertreatment systems in an accelerated
fashion to produce an aged aftertreatment system for durability
demonstration. Determine the target number of hours that represents
useful life for an engine family as described in the standard setting
part. The method described is a procedure for translating field data
that represents a given application into an accelerated aging cycle for
that specific application, as well as methods for carrying out aging
using that cycle. The procedure is intended to be representative of
field aging, includes exposure to elements of both thermal and chemical
aging, and is designed to achieve an acceleration of aging that is ten
times a dynamometer or field test (1,000 hours of accelerated aging is
equivalent to 10,000 hours of standard aging).
    (a) Development of an application-specific accelerated aging cycle
generally consists of the following steps:
    (1) Gathering and analysis of input field data.
    (2) Determination of key components for aging.
    (3) Determination of a thermal deactivation coefficient for each
key component.
    (4) Determination of potential aging modes using clustering
analysis.
    (5) Down-selection of final aging modes.
    (6) Incorporation of regeneration modes (if necessary).
    (7) Cycle generation.
    (8) Calculation of thermal deactivation.
    (9) Cycle scaling to reach thermal deactivation.
    (10) Determination of oil exposure rates.
    (11) Determination of sulfur exposure rates.
    (b) There are two methods for using field data to develop aging
cycles, as described in Sec.  1065.1139(b)(1) and (2). Method selection
depends on the type of field data available. Method 1 directly uses
field data to generate aging modes, while Method 2 uses field data to
weight appropriate regulatory duty cycles that are used for emissions
certification.
    (c) Carry out accelerated aging on either a modified engine
platform or a reactor-based burner platform. The requirements for these
platforms are described in Sec.  1065.1141 for engine bench aging and
Sec.  1065.1143 for burner-based bench aging.

Sec.  1065.1133  Application selection, data gathering, and analysis.

    This section describes the gathering and analysis of the field
generated data that is required for generation of the data cycle.
Gather data for the determination of aftertreatment exposure to
thermal, lubricating oil, and sulfur related aging factors. You are not
required to submit this data as part of your application, but you must
make this data available if we request it.
    (a) Field data target selection. Use good engineering judgment to
select one or more target applications for gathering of input field
data for the accelerated aging cycle generation that represent a
greater than average exposure to potential field aging factors. It
should be noted that the same application may not necessarily represent
the worst case for all aging factors. If sufficient data is not
available to make this determination with multiple applications, you
may select the application that is expected to have the highest sales
volume for a given engine family.
    (1) Thermal exposure. We recommend that you select applications for
a given engine family that represent the 90th percentile of exposure to
thermal aging. For example, if a given engine family incorporates a
periodic infrequent regeneration event that involves exposure to higher
temperatures than are observed during normal (non-regeneration)
operation, we recommend that you select an application wherein the
total duration of the cumulative regeneration events is at the 90th
percentile of expected applications for that family. For an engine that
does not incorporate a distinct regeneration event, we recommend
selecting an application that represents the 90th percentile in terms
of the overall average temperature.
    (2) Oil exposure. Use a combination of field and laboratory
measurements to determine an average rate of oil consumption in grams
per hour that reaches the exhaust. You may use the average total oil
consumption rate of the engine if you are unable to determine what
portion of the oil consumed reaches the exhaust aftertreatment.
    (3) Sulfur exposure. The total sulfur exposure is the sum of fuel-
and oil-related sulfur. Oil-related sulfur will be accounted for in the
acceleration of oil exposure directly. We recommend that you determine
fuel-related sulfur exposure by selecting an application that
represents the 90th percentile of fuel consumption. Use good
engineering judgment to determine that average rate of fuel consumption
for the target application. You may use a combination of field and
laboratory measurements to make this determination. Calculate the
average rate of fuel-related sulfur exposure in grams per hour from the
average rate of fuel consumption assuming a fuel sulfur level of 10 ppm
by weight.
    (b) Application data gathering. Use good engineering judgment to
gather data from one or more field vehicles to support the accelerated
aging cycle generation. We recommend that you gather data at a
recording frequency of 1 Hz. The type of data that you gather will
depend on the method you plan to use for cycle generation. Record both
the data and the number of engine operating hours which that data
represents regardless of method, as this information will be used to
scale the cycle calculations. Use good engineering judgment to ensure
that the amount of data recorded provides an accurate representation of
field operation for the target application. If your application
includes a periodic regeneration event, you must record multiple events
to ensure that you have accurately captured the variation of those
events. We recommend that you record at least 300 hours of field
operation, and at least 3 different regeneration events if applicable.
    (1) When using Method 1, direct field data use, as described in
Sec.  1065.1139(b)(1), record data for exhaust flow rate and at least
one representative inlet temperature for each major aftertreatment
system catalyst component, such as a diesel oxidation catalyst (DOC),
diesel particulate filter (DPF), or selective catalytic reduction (SCR)
catalyst. If a given catalyst component has multiple substrates
installed directly in sequence, it is sufficient to record only the
inlet temperature for the first catalyst substrate in the sequence. It
is not necessary to record separate temperatures for substrates that
are ``zone-coated'' with multiple catalyst functions. Record a
representative outlet temperature for any major catalyst component that
is used to elevate the temperature of downstream components. This could
be the inlet of the next major component if that would be
representative. We recommend that you record engine fuel rate to assist
in the determination of sulfur exposure rates, but you may use other
data for this purpose.
    (2) When using Method 2, weighting of certification cycles, as
described

Sec.  1065.1139(b)(2), record data for engine speed and engine load.
Record sufficient ECM load parameters to determine a torque value that
can be compared directly to engine torque as measured in the
laboratory. You may optionally use ECM fuel rate measurements to
determine load, but only if the same measurements can also be performed
during laboratory testing on certification test cycles using sensors
with comparable response characteristics. For example, you could use
ECM fuel consumption rates for both field data and during laboratory
tests.
    (i) Optionally, as an alternative to the parameters required in
this paragraph (b)(2), you may use a system exhaust temperature
measurement to represent load. This requires one recorded temperature
that represents the aftertreatment system. We recommend that you use a
temperature recorded at the outlet of the first major catalyst
component. If you choose to use this option, you must use the same
temperature sensor for both field and laboratory measurements. Do not
compare measurements between on-engine production temperature sensors
with laboratory temperature sensors.
    (ii) Optionally, as an alternative to the parameters required in
this paragraph (b)(2), you may use exhaust flow and temperature
measurements recorded in the field to support Method 2 calculations.
Only one recorded temperature that represents the aftertreatment system
is needed in this case. We recommend that you use a temperature
recorded at the outlet of the first major catalyst component. Do not
compare measurements between on-engine production temperature sensors
with laboratory temperature sensors.
    (3) If you have an aftertreatment system which involves periodic
regeneration events where the temperature is raised above levels
observed during normal operation, you must record data to characterize
each such event. Data must be recorded at a frequency of at least 1 Hz,
and you must record the exhaust flow rate and inlet temperature of each
key catalyst component that will experience elevated temperatures
during the regeneration. In addition, record a flag or variable that
can be used to determine the beginning and end of a regeneration event.
You must record at least three such events to allow determination of
the average regeneration profile. If you have multiple types of
regeneration events which influence different catalyst components in
the system, you must record this data for each type of event
separately. Use good engineering judgment to determine the average
duration of each type of regeneration event, and the average interval
of time between successive regeneration events of that type. You may
use the data recorded for this cycle determination, or any other
representative data to determine average regeneration duration or
regeneration interval. These values may be determined from the analysis
used to determine emission adjustments to account for infrequent
regeneration of aftertreatment devices in Sec.  1065.680.

Sec.  1065.1135  Determination of key aftertreatment system components.

    Most compression-ignition engine aftertreatment systems contain
multiple catalysts, each with their own aging characteristics. However,
in the accelerated aging protocol the system will be aged as a whole.
Therefore, it is necessary to determine which catalyst components are
the key components that will be used for deriving and scaling the aging
cycle.
    (a) The primary aging catalyst in an aftertreatment system is the
catalyst that is directly responsible for the majority of
NOX reduction, such as a urea SCR catalyst in a compression
ignition aftertreatment system. This catalyst will be used as the basis
for cycle generation. If a system contains multiple SCR catalysts that
are separated by other heat generating components that would result in
a different rate of heat exposure, then each SCR catalyst must be
tracked separately. Use good engineering judgment to determine when
there are multiple primary catalyst components. An example of this
would be a light-off SCR catalyst placed upstream of a DOC which is
used to generate heat for regeneration and is followed by a DPF and a
second downstream SCR catalyst. In this case, both the light-off SCR
and the downstream SCR would have very different thermal history, and
therefore must be tracked separately. In applications where there is no
SCR catalyst in the aftertreatment system, the primary catalyst is the
first oxidizing catalyst component in the system which is typically a
DOC or catalyzed DPF.
    (b) The secondary aging catalyst in an aftertreatment system is the
catalyst that is intended to either alter exhaust characteristics or
generate elevated temperature upstream of the primary catalyst. An
example of a secondary component catalyst would be a DOC placed
upstream of an SCR catalyst, with or without a DPF in between.

Sec.  1065.1137  Determination of thermal reactivity coefficient.

    This section describes the method for determining the thermal
reactivity coefficient(s) used for thermal heat load calculation in the
accelerated aging protocol.
    (a) The calculations for thermal degradation are based on the use
of an Arrhenius rate law function to model cumulative thermal
degradation due to heat exposure. Under this model, the thermal aging
rate constant, k, is an exponential function of temperature which takes
the form shown in the following equation:
[GRAPHIC] [TIFF OMITTED] TR24JA23.146

Where:

A = frequency factor or pre-exponential factor.
Ea = thermal reactivity coefficient in kJ/mol.
R = molar gas constant.
T = catalyst temperature in K.

    (b) The process of determining Ea begins with
determining what catalyst characteristic will be tracked as the basis
for measuring thermal deactivation. This metric varies for each type of
catalyst and may be determined from the experimental data using good
engineering judgment. We recommend the following metrics; however, you
may also use a different metric based on good engineering judgment:
    (1) Copper-based zeolite SCR. Total ammonia storage capacity is a
key aging metric for copper-zeolite SCR catalysts, and they typically
contain multiple types of storage sites. It is typical to model these
catalysts using two different storage sites, one of which is more
active for NOX reduction, as this has been shown to be an
effective metric for tracking thermal aging. In this case, the
recommended aging metric is the ratio between the storage capacity of
the two sites, with more active site being in the denominator.
    (2) Iron-based zeolite SCR. Total ammonia storage capacity is a key
aging metric for iron-zeolite SCR catalysts using a single storage site
at 250 [deg]C for tracking thermal aging.
    (3) Vanadium SCR. Vanadium-based SCR catalysts do not feature a
high level of ammonia storage like zeolites, therefore NOX
reduction efficiency at lower temperatures in the range of 250 [deg]C
is the recommended metric for tracking thermal aging.
    (4) Diesel oxidation catalysts. Conversion rate of NO to
NO2 at 200 [deg]C is the key aging metric for tracking
thermal aging for DOCs which are used to optimize exhaust
characteristics for a

downstream SCR system. HC reduction efficiency (as measured using
ethylene) at 200 [deg]C is the key aging metric for DOCs which are part
of a system that does not contain an SCR catalyst for NOX
reduction. This same guidance applies to an oxidation catalyst coated
onto the surface of a DPF, if there is no other DOC in the system.
    (c)(1) Use good engineering judgment to select at least three
different temperatures to run the degradation experiments at. We
recommend selecting these temperatures to accelerated thermal
deactivation such that measurable changes in the aging metric can be
observed at multiple time points over the course of no more than 50
hours. Avoid temperatures that are too high to prevent rapid catalyst