C1 basis. Note that calculating HC masses from molar
concentrations and molar masses is only valid where they are each
expressed on the same carbon basis.
* * * * *
    Oxygenated fuels means fuels composed of at least 25% oxygen-
containing compounds, such as ethanol or methanol. Testing engines that
use oxygenated fuels generally requires the use of the sampling methods
in subpart I of this part. However, you should read the standard-
setting part and subpart I of this part to determine appropriate
sampling methods.
* * * * *
    Precision means two times the standard deviation of a set of
measured values of a single zero or reference quantity. See also the
related definitions of noise and repeatability in this section.
* * * * *
0
281. Section 1065.1005 is amended by revising paragraphs (a) and (f)(2)
to read as follows:

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

* * * * *
    (a) Symbols for quantities. This part uses the following symbols
and units of measure for various quantities:

--------------------------------------------------------------------------------------------------------------------------------------------------------
       Symbol                      Quantity                           Unit                    Unit symbol            Units in terms of SI base units
--------------------------------------------------------------------------------------------------------------------------------------------------------
[alpha]............  atomic hydrogen to carbon ratio.....  mole per mole.............  mol/mol.................  1
A..................  area................................  square meter..............  m\2\....................  m\2\
A0.................  intercept of least squares
                      regression.
A1.................  slope of least squares regression...
[beta].............  ratio of diameters..................  meter per meter...........  m/m.....................  1
[beta].............  atomic oxygen to carbon ratio.......  mole per mole.............  mol/mol.................  1
C#.................  number of carbon atoms in a molecule
d..................  Diameter............................  meter.....................  m.......................  m
DR.................  dilution ratio......................  mole per mol..............  mol/mol.................  1
[egr]..............  error between a quantity and its
                      reference.
e..................  brake-specific emission or fuel       gram per kilowatt hour....  g/(kW[middot]hr)........  g[middot]3.6-1[middot]10\6\[middot]m-
                      consumption.                                                                                2[middot]kg[middot]s\2\
F..................  F-test statistic....................
f..................  frequency...........................  hertz.....................  Hz......................  s-1
fn.................  angular speed (shaft)...............  revolutions per minute....  r/min...................  2[middot][pi][middot]60-
                                                                                1[middot]m[middot]m-1[middot]s-1

[gamma]............  ratio of specific heats.............  (joule per kilogram         (J/(kg[middot]K))/(J/     1
                                                            kelvin) per (joule per      (kg[middot]K)).
                                                            kilogram kelvin).
K..................  correction factor...................  1.........................
Kv.................  calibration coefficient.............  ..........................  m\4\[middot]s[middot]K\0  m\4\[middot]s[middot]K\0.5\[middot]kg-1
                                                                                .5\/kg.
l..................  length..............................  meter.....................  m.......................  m
[mu]...............  viscosity, dynamic..................  pascal second.............  Pa[middot]s.............  m-1[middot]kg[middot]s-1
M..................  molar mass\1\.......................  gram per mole.............  g/mol...................  10-3[middot]kg[middot]mol-1
m..................  mass................................  kilogram..................  kg......................  kg
m..................  mass rate...........................  kilogram per second.......  kg/s....................  kg[middot]s-1
[nu]...............  viscosity, kinematic................  meter squared per second..  m\2\/s..................  m\2\[middot]s-1
N..................  total number in series..............
n..................  amount of substance.................  mole......................  mol.....................  mol
n..................  amount of substance rate............  mole per second...........  mol/s...................  mol[middot]s-1
P..................  power...............................  kilowatt..................  kW......................  10\3\[middot]m\2\[middot]kg[middot]s-3
PF.................  penetration fraction................
p..................  pressure............................  pascal....................  Pa......................  m-1[middot]kg[middot]s-2
[rho]..............  mass density........................  kilogram per cubic meter..  kg/m\3\.................  kg[middot]m-3
r..................  ratio of pressures..................  pascal per pascal.........  Pa/Pa...................  1
R\2\...............  coefficient of determination........
Ra.................  average surface roughness...........  micrometer................  [mu]m...................  10-6 m
Re#................  Reynolds number.....................
RF.................  response factor.....................
RH.................  relative humidity...................
[sigma]............  non-biased standard deviation.......
S..................  Sutherland constant.................  kelvin....................  K.......................  K
SEE................  standard estimate of error..........
T..................  absolute temperature................  kelvin....................  K.......................  K
T..................  Celsius temperature.................  degree Celsius............  [deg]C..................  K-273.15
T..................  torque (moment of force)............  newton meter..............  N[middot]m..............  m\2\[middot]kg[middot]s-2
t..................  time................................  second....................  s.......................  s
[Delta]t...........  time interval, period, 1/frequency..  second....................  s.......................  s
V..................  volume..............................  cubic meter...............  m\3\....................  m\3\
V..................  volume rate.........................  cubic meter per second....  m\3\/s..................  m\3\[middot]s-1
W..................  work................................  kilowatt hour.............  kW[middot]hr............  3.6[middot]10-
                                                                                6[middot]m\2\[middot]kg[middot]s-2
wc.................  carbon mass fraction................  gram per gram.............  g/g.....................  1
x..................  amount of substance mole fraction     mole per mole.............  mol/mol.................  1
                      \2\.
x..................  flow-weighted mean concentration....  mole per mole.............  mol/mol.................  1
y..................  generic variable....................
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ See paragraph (f)(2) of this section for the values to use for molar masses. Note that in the cases of NOX and HC, the regulations specify effective
  molar masses based on assumed speciation rather than actual speciation.
\2\ Note that mole fractions for THC, THCE, NMHC, NMHCE, and NOTHC are expressed on a C1 equivalent basis.

* * * * *
    (f) * * *
    (2) This part uses the following molar masses or effective molar
masses of chemical species:

----------------------------------------------------------------------------------------------------------------
                                                                             g/mol (10-\3\[middot]kg[middot]mol-
        Symbol                                Quantity                                       \1\)
----------------------------------------------------------------------------------------------------------------
Mair..................  molar mass of dry air \1\..........................  28.96559
MAr...................  molar mass of argon................................  39.948
MC....................  molar mass of carbon...............................  12.0107
MCH3OH................  molar mass of methanol.............................  32.04186
MC2H5OH...............  molar mass of ethanol..............................  46.06844
MC2H4O................  molar mass of acetaldehyde.........................  44.05256
MC3H8.................  molar mass of propane..............................  44.09562
MC3H7OH...............  molar mass of propanol.............................  60.09502
MCO...................  molar mass of carbon monoxide......................  28.0101
MCH4..................  molar mass of methane..............................  16.0425
MCO2..................  molar mass of carbon dioxide.......................  44.0095
MH....................  molar mass of atomic hydrogen......................  1.00794
MH2...................  molar mass of molecular hydrogen...................  2.01588
MH2O..................  molar mass of water................................  18.01528
MHCHO.................  molar mass of formaldehyde.........................  30.02598
MHe...................  molar mass of helium...............................  4.002602
MN....................  molar mass of atomic nitrogen......................  14.0067
MN2...................  molar mass of molecular nitrogen...................  28.0134
MNH3..................  molar mass of ammonia..............................  17.03052

MNMHC.................  effective C1 molar mass of nonmethane hydrocarbon    13.875389
                         \2\.
MNMHCE................  effective C1 molar mass of nonmethane hydrocarbon    13.875389
                         equivalent \2\.
MNOx..................  effective molar mass of oxides of nitrogen \3\.....  46.0055
MN2O..................  molar mass of nitrous oxide........................  44.0128
MO....................  molar mass of atomic oxygen........................  15.9994
MO2...................  molar mass of molecular oxygen.....................  31.9988
MS....................  molar mass of sulfur...............................  32.065
MTHC..................  effective C1 molar mass of total hydrocarbon \2\...  13.875389
MTHCE.................  effective C1 molar mass of total hydrocarbon         13.875389
                         equivalent \2\.
----------------------------------------------------------------------------------------------------------------
\1\ See paragraph (f)(1) of this section for the composition of dry air.
\2\ The effective molar masses of THC, THCE, NMHC, and NMHCE are defined on a C1 basis and are based on an
  atomic hydrogen-to-carbon ratio, [alpha], of 1.85 (with [beta], [gamma], and [delta] equal to zero).
\3\ The effective molar mass of NOX is defined by the molar mass of nitrogen dioxide, NO2.

* * * * *
0
282. Section 1065.1010 is amended by revising paragraphs (a) and (f) to
read as follows:

Sec.  1065.1010  Reference materials.

* * * * *
    (a) ASTM materials. Copies of these materials may be obtained from
ASTM International, 100 Barr Harbor Dr., P.O. Box C700, West
Conshohocken, PA 19428-2959, or by calling (877) 909-ASTM, or at http://www.astm.org.
    (1) ASTM D86-11b, Standard Test Method for Distillation of
Petroleum Products at Atmospheric Pressure, IBR approved for Sec. Sec.
1065.703, 1065.710.
    (2) ASTM D93-12, Standard Test Methods for Flash Point by Pensky-
Martens Closed Cup Tester, IBR approved for Sec.  1065.703.
    (3) ASTM D445-12, Standard Test Method for Kinematic Viscosity of
Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity),
IBR approved for Sec.  1065.703.
    (4) ASTM D613-10a, Standard Test Method for Cetane Number of Diesel
Fuel Oil, IBR approved for Sec.  1065.703.
    (5) ASTM D910-11, Standard Specification for Aviation Gasolines,
IBR approved for Sec.  1065.701.
    (6) ASTM D975-12a, Standard Specification for Diesel Fuel Oils, IBR
approved for Sec.  1065.701.
    (7) ASTM D1267-02 (Reapproved 2007), Standard Test Method for Gage
Vapor Pressure of Liquefied Petroleum (LP) Gases (LP-Gas Method), IBR
approved for Sec.  1065.720.
    (8) ASTM D1319-10, Standard Test Method for Hydrocarbon Types in
Liquid Petroleum Products by Fluorescent Indicator Adsorption, IBR
approved for Sec.  1065.710.
    (9) ASTM D1655-12, Standard Specification for Aviation Turbine
Fuels, IBR approved for Sec.  1065.701.
    (10) ASTM D1837-11, Standard Test Method for Volatility of
Liquefied Petroleum (LP) Gases, IBR approved for Sec.  1065.720.
    (11) ASTM D1838-12, Standard Test Method for Copper Strip Corrosion
by Liquefied Petroleum (LP) Gases, IBR approved for Sec.  1065.720.
    (12) ASTM D1945-03 (Reapproved 2010), Standard Test Method for
Analysis of Natural Gas by Gas Chromatography, IBR approved for Sec.
1065.715.
    (13) ASTM D2158-11, Standard Test Method for Residues in Liquefied
Petroleum (LP) Gases, IBR approved for Sec.  1065.720.
    (14) ASTM D2163-07, Standard Test Method for Analysis of Liquefied
Petroleum (LP) Gases and Propene Concentrates by Gas Chromatography,
IBR approved for Sec.  1065.720.
    (15) ASTM D2598-02 (Reapproved 2007), Standard Practice for
Calculation of Certain Physical Properties of Liquefied Petroleum (LP)
Gases from Compositional Analysis, IBR approved for Sec.  1065.720.
    (16) ASTM D2622-10, Standard Test Method for Sulfur in Petroleum
Products by Wavelength Dispersive X-ray Fluorescence Spectrometry, IBR
approved for Sec. Sec.  1065.703, 1065.710.
    (17) ASTM D2713-12, Standard Test Method for Dryness of Propane
(Valve Freeze Method), IBR approved for Sec.  1065.720.
    (18) ASTM D2784-11, Standard Test Method for Sulfur in Liquefied
Petroleum Gases (Oxy-Hydrogen Burner or Lamp), IBR approved for Sec.
1065.720.
    (19) ASTM D2880-03 (Reapproved 2010), Standard Specification for
Gas Turbine Fuel Oils, IBR approved for Sec.  1065.701.
    (20) ASTM D2986-95a (Reapproved 1999), Standard Practice for
Evaluation of Air Assay Media by the Monodisperse DOP (Dioctyl
Phthalate) Smoke Test, IBR approved for Sec.  1065.170.
    (21) ASTM D3231-11, Standard Test Method for Phosphorus in
Gasoline, IBR approved for Sec.  1065.710.
    (22) ASTM D3237-12, Standard Test Method for Lead in Gasoline By
Atomic Absorption Spectroscopy, IBR approved for Sec.  1065.710.
    (23) ASTM D4052-11, Standard Test Method for Density and Relative
Density of Liquids by Digital Density Meter, IBR approved for Sec.
1065.703.
    (24) ASTM D4629-12, Standard Test Method for Trace Nitrogen in
Liquid Petroleum Hydrocarbons by Syringe/Inlet Oxidative Combustion and
Chemiluminescence Detection, IBR approved for Sec.  1065.655.
    (25) ASTM D4814-11b, Standard Specification for Automotive Spark-
Ignition Engine Fuel, IBR approved for Sec.  1065.701.
    (26) ASTM D4815-09, Standard Test Method for Determination of MTBE,
ETBE, TAME, DIPE, tertiary-Amyl Alcohol and C1 to
C4 Alcohols in Gasoline by Gas Chromatography, IBR approved
for Sec.  1065.710.
    (27) ASTM D5186-03 (Reapproved 2009), Standard Test Method for
Determination of the Aromatic Content and Polynuclear Aromatic Content
of Diesel Fuels and Aviation Turbine Fuels By Supercritical Fluid
Chromatography, IBR approved for Sec.  1065.703.
    (28) ASTM D5191-12, Standard Test Method for Vapor Pressure of
Petroleum Products (Mini Method), IBR approved for Sec.  1065.710.
    (29) ASTM D5291-10, Standard Test Method for Instrumental
Determination of Carbon, Hydrogen, and Nitrogen in Petroleum Products
and Lubricants, IBR approved for Sec.  1065.655.
    (30) ASTM D5599-00 (Reapproved 2010), Standard Test Method for
Determination of Oxygenates in Gasoline by Gas Chromatography and
Oxygen Selective Flame Ionization Detection, IBR approved for Sec.
1065.655.
    (31) ASTM D5762-12, Standard Test Method for Nitrogen in Petroleum
and

Petroleum Products by Boat-Inlet Chemiluminescence, IBR approved for
Sec.  1065.655.
    (32) ASTM D5797-07, Standard Specification for Fuel Methanol (M70-
M85) for Automotive Spark-Ignition Engines, IBR approved for Sec.
1065.701.
    (33) ASTM D5798-11, Standard Specification for Fuel Ethanol (Ed75-
Ed85) for Automotive Spark-Ignition Engines, IBR approved for Sec.
1065.701.
    (34) ASTM D6615-11a, Standard Specification for Jet B Wide-Cut
Aviation Turbine Fuel, IBR approved for Sec.  1065.701.
    (35) ASTM D6751-12, Standard Specification for Biodiesel Fuel Blend
Stock (B100) for Middle Distillate Fuels, IBR approved for Sec.
1065.701.
    (36) ASTM D6985-04a, Standard Specification for Middle Distillate
Fuel Oil--Military Marine Applications, IBR approved for Sec.
1065.701.
    (37) ASTM F1471-09, Standard Test Method for Air Cleaning
Performance of a High- Efficiency Particulate Air Filter System, IBR
approved for Sec.  1065.1001.
* * * * *
    (f) SAE material. Copies of these materials may be obtained from
the Society of Automotive Engineers International, 400 Commonwealth
Dr., Warrendale, PA 15096-0001, or by calling<PHONE_NUMBER>, or at
http://www.sae.org.
    (1) SAE 770141, 1977, Optimization of Flame Ionization Detector for
Determination of Hydrocarbon in Diluted Automotive Exhausts, Glenn D.
Reschke, IBR approved for Sec.  1065.360.
    (2) SAE J1151, Methane Measurement Using Gas Chromatography,
Revised September 2011, IBR approved for Sec. Sec.  1065.267 and
1065.750.

0
283. A new subpart L is added to read as follows:
Subpart L--Methods for Unregulated and Special Pollutants
Sec.
1065.1101 Applicability.
Semi-Volatile Organic Compounds
1065.1103 General provisions for SVOC measurement.
1065.1105 Sampling system design.
1065.1107 Sample media and sample system preparation; sampler
assembly.
1065.1109 Post-test sampler disassembly and sample extraction.
1065.1111 Sample analysis.

Subpart L--Methods for Unregulated and Special Pollutants

Sec.  1065.1101  Applicability.

    This subpart specifies procedures that may be used to measure
emission constituents that are not measured (or not separately
measured) by the test procedures in the other subparts of this part.
These procedures are included to facilitate consistent measurement of
unregulated pollutants primarily for purposes other than compliance
with emission standards. Unless otherwise specified in the standard-
setting part, use of these procedures is optional and does not replace
any requirements in the rest of this part.
Semi-Volatile Organic Compounds

Sec.  1065.1103  General provisions for SVOC measurement.

    The provisions of Sec. Sec.  1065.1103 through 1065.1111 specify
procedures for the measurement of semi-volatile organic compounds
(SVOC) along with PM. The provisions of these sections specify how to
collect a sample of the SVOCs during exhaust testing procedures, as
well as how to use wet chemistry techniques to extract SVOCs from the
sample media for analysis. Note that the precise method you use will
depend on the category of SVOCs being measured. For example, the method
used to measure polynuclear aromatic hydrocarbons (PAHs) will differ
slightly from the method used to measure dioxins.
    (a) Laboratory cleanliness is especially important throughout the
course of SVOC testing. Thoroughly clean all sample train components
and glassware before testing to avoid sample contamination.
    (b) Throughout the course of your testing we recommend that media
blanks be analyzed for each batch of media (sorbent, filters, etc.)
that is prepared for testing. Blank sorbent modules with inlet and
outlet covered (i.e., field blanks) should periodically accompany the
test sample train throughout the course of a test, including the sample
train and sorbent module disassembly, sample packaging, and storage.
Use good engineering judgment to determine the frequency of field
blanks. During testing, the field blank sample train should reside in
close proximity to the sampler.
    (c) We recommend the use of isotope dilution techniques, including
the use of isotopically labeled surrogate, internal, alternate, and
injection standards.
    (d) If your target analytes degrade when exposed to ultraviolet
radiation (such as nPAH), perform these procedures in the dark or with
ultraviolet filters installed over the lights.
    (e) Follow standard analytic chemistry methods for aspects of the
analysis not specified.
    (f) The following definitions and abbreviations apply for SVOC
measurements:
    (1) Soxhlet extraction means the extraction method invented by
Franz von Soxhlet, in which the sample is placed in a thimble and
rinsed repeatedly with a recycle of the extraction solvent.
    (2) XAD-2 means a hydrophobic cross linked polystyrene copolymer
resin adsorbent known commercially as Amberlite[supreg] XAD[supreg]-2,
or an equivalent adsorbent.
    (3) Semi-volatile organic compound (SVOC) means an organic compound
that is sufficiently volatile to exist in vapor form in engine exhaust,
but that readily condenses to liquid or solid form under atmospheric
conditions. Most SVOCs have at least 14 carbon atoms per molecule and
have a boiling point between 240 [deg]C and 400 [deg]C. SVOCs include
dioxin, quinone, and nitro-PAH compounds. They may be a natural
byproduct of combustion or created post combustion. Note that SVOCs may
be detected as hydrocarbons and/or PM using the measurement procedures
specified in this part; in other words, some fraction of measured mass
of hydrocarbons and/or PM may be SVOCs.
    (4) Kuderna-Danish concentrator means laboratory glassware known by
this name that consists of an air-cooled condenser on top of an
extraction bulb.
    (5) Dean-Stark trap means laboratory glassware known by this name
that uses a reflux condenser to collect water from samples extracted
under reflux.
    (6) PUF means polyurethane foam.
    (7) Isotopically labeled means relating to a compound in which
either all of the hydrogen atoms are replaced with the atomic isotope
hydrogen-2 (deuterium) or one of the carbon atoms at a defined position
in the molecule is replaced with the atomic isotope carbon-13.

Sec.  1065.1105  Sampling system design.

    (a) General. We recommend that you design your SVOC batch sampler
to extract sample from undiluted emissions to minimize the amount of
SVOCs lost to the system. To the extent practical, adjust sampling
times based on the rate of emission of target analytes from the engine
to obtain analyte concentrations above the limit of detection. In some
instances you may need to run repeat test cycles without replacing the
sample media or disassembly of the batch sampler.
    (b) Sample probe, transfer lines, and sample media holder design
and construction. The sampling system should consist of a sample probe,
transfer line, PM filter holder, cooling coil, sorbent module, and
condensate trap. Construct sample probes, transfer lines, and sample
media holders that

have inside surfaces of Nickel, Titanium or another nonreactive
material capable of withstanding raw exhaust gas temperatures. All
joints in the hot zone of the system should be sealed with gaskets made
of nonreactive material similar to that of the sample train components.
Teflon gaskets may be used in the cold zone. We recommend keeping the
sampling system length as short as possible by locating all components
as close to probes as practical to minimize the surface exposed to the
exhaust.
    (c) Sample system configuration. This paragraph (c) specifies the
components necessary to collect SVOC samples, along with our
recommended design parameters. Where you do not follow our
recommendations, use good engineering judgment to design your sampling
system so that it does not result in loss of SVOC during sampling. The
sampling system should contain the following components in series in
the order listed:
    (1) Sample probe. Use a sample probe similar to the PM sample probe
specified in subpart B of this part. We recommend that you heat the
sample probe with a set point no higher the 200 [deg]C. Note that heat
from the engine exhaust may cause the probe temperature to exceed 200
[deg]C at some points during the test.
    (2) Filter holder. Use a PM filter holder similar to type of holder
specified in subpart B of this part, although you will likely need to
use a larger size to accommodate the high sample flow rates. We
recommend the use of 110 mm filter for the testing of engines that
utilize exhaust after treatment for removal of PM and 293 mm filters
for engines that do not. You may heat the filter holder, but we
recommend that your set point does not exceed 200 [deg]C. Note that
this differs from normal PM sampling procedures which maintain the
filter at a much lower temperature to capture a significant fraction of
exhaust SVOCs on the filter. In this method SVOCs that pass through the
filter will be collected on the downstream sorbent module.
    (3) Cooling coil. Use good engineering judgment to design a cooling
coil (to be used with the water bath described in paragraph (e) of this
section) that will drop the sample temperature to approximately 5
[deg]C. Note that downstream of the cooling coil, the sample will be a
mixture of a vapor phase hydrocarbons in CO2 and air and a
primarily aqueous liquid phase.
    (4) Sorbent and sorbent module. Use a hydrophobic sorbent in a
sealed sorbent module. Note that this sorbent module is intended to be
the final stage for collecting the SVOC sample and should be sized
accordingly. We recommend sizing the module to hold 40 g of XAD-2 along
with polyurethane (PUF) plugs at either end of the module.
    (5) Condensate trap/drain. Include a condensate trap to separate
the aqueous liquid phase from the gas stream. We recommend using a
peristaltic pump to remove water from the condensate trap over the
course of the test to prevent build up of the condensate. Note that for
some tests it may be appropriate to collect this water for analysis.
    (d) Sampler flow control. For testing using the recommended filter
and sorbent module sizes, we recommended targeting an average sample
flow rate of 70 l/min to maximize SVOC collection. The sampler must be
designed to maintain proportional sampling throughout the test. Verify
proportional sampling after an emission test as described in Sec.
1065.545.
    (e) Water bath. Design the sample system with a water bath in which
the cooling coil, sorbent module, and condensate trap will be
submerged. Use a heat exchanger or ice to maintain the bath temperature
at (3 to 7) [deg]C.

Sec.  1065.1107  Sample media and sample system preparation; sampler
assembly.

    This section describes the types of sample media to be used as well
as the cleaning procedure required to prepare the media and wetted
sample surfaces for sampling.
    (a) Sample media. The sampling system uses two types of sample
media in series: The first to simultaneously capture the PM and some of
the SVOCs, and a second to capture SVOCs that remain in the gas phase.
Use the following sample media for capture of PM and gas phase SVOCs:
    (1) For capture of PM, use pure quartz filters that do not contain
any binder. Size the filter diameter to account for the expected PM
emission rate, sample flow rate, and number of repeat tests to minimize
filter change intervals. Note that when repeating test cycles to
increase sample mass, you may replace the filter without replacing the
sorbent or otherwise disassembling the batch sampler. In those cases
include all filters in the extraction.
    (2) For capture of gaseous SVOCs, utilize XAD-2 resin contained
between two PUF plugs.
    (b) Sample media and sampler preparation. Prepare pre-cleaned PM
filters and pre-cleaned PUF/XAD-2 as needed. If the media is not to be
used immediately after cleaning, store it in containers protected from
light and ambient air.
    (1) Pre-clean the filters via Soxhlet extraction with methylene
chloride for 24 hours and dry over dry nitrogen in a low temperature
vacuum oven.
    (2) Pre-clean PUF and XAD-2 via a series of Soxhlet extractions: 8
h with water, 22 h with methanol, 22 h with methylene chloride, and 22
hours with toluene followed by drying with nitrogen.
    (3) Clean sampler components including the probe, filter holder,
condenser, sorbent module, and condensate collection vessel by rinsing
three times with methylene chloride followed by three rinses with
toluene. Prepare pre-cleaned aluminum foil for capping the probe inlet
of the sampler after the sample train has been assembled.
    (c) Sorbent spiking. Use good engineering judgment to verify the
extent to which your extraction methods recover SVOCs absorbed to the
sample media. We recommend spiking the XAD-2 resin with a surrogate
standard prior to testing with a carbon-13 or hydrogen-2 isotopically
labeled standard for each of the class of analytes targeted for
analysis. Perform this spiking as follows:
    (1) Insert the lower PUF plug into the bottom of the sorbent
module.
    (2) Add half of one portion of XAD-2 resin to the module and spike
the XAD-2 in the module with the standard.
    (3) Wait 1 hour for the solvent from the standard(s) to evaporate
and then add the remaining 20 g of the XAD-2 resin to the module
followed by the top PUF plug.
    (4) Cover the inlet and outlet of the sorbent module with pre-
cleaned aluminum foil.
    (d) Sample train assembly. Upon completion of the sample media and
sampler preparation, assemble the condensate trap, cooling coil, filter
holder with filter, and sample probe to the sorbent module and lower
assembly into the reservoir. Cover the probe inlet with pre-cleaned
aluminum foil.

Sec.  1065.1109  Post-test sampler disassembly and sample extraction.

    This section describes the process for sample train disassembly,
sample train rinsing, sample extraction, and sample clean-up.
    (a) Sample train disassembly. Disassemble the sample train in a
clean environment upon completion of testing. Prepare to extract the
SVOCs as follows:
    (1) Remove the PM filter, PUF, and all of the XAD-2 from the sample
train and place them into a Soxhlet extraction

thimble. If the sample media are to be stored, store them at <= 37
[deg]C.
    (2) Rinse sample train wetted surfaces upstream of the condensate
trap with acetone followed by toluene (or a comparable solvent system),
ensuring that all of the solvent that remains in liquid phase is
collected (note that a fraction of the acetone and toluene will likely
be lost via evaporation during mixing.) Rinse with solvent volumes that
are sufficient to cover the all of the surfaces exposed to sample
during testing. We recommend three fresh solvent rinses with acetone
and two with toluene. We recommend rinse volumes of 60 mL per rinse for
all sample train components except the condenser coil, of which you
should use 200 mL per rinse. Keep the acetone rinsate separate from the
toluene rinsate to the extent practicable. Rinsate fractions should be
stored separately in glass bottles that have been pre-rinsed with
acetone, hexane, and toluene (or bottles purchased pre-cleaned).
    (3) Use good engineering judgment to determine if you should
analyze the aqueous condensate phase for SVOCs. If you determine that
analysis is necessary, use toluene to perform a liquid-liquid
extraction of the SVOCs from the collected aqueous condensate using a
sepratory funnel or equivalent. Add the toluene from this aqueous
extraction to the toluene rinsate fraction mentioned in paragraph
(a)(2) of this section.
    (4) Reduce rinsate solvent volumes as needed using a Kuderna-Danish
concentrator or rotary evaporator and retain these rinse solvents for
reuse during sample media extraction for the same test. Care should be
taken when concentrating via rotary evaporation to avoid loss of low
molecular weight analytes.
    (b) Sample extraction. Extract the SVOCs from the sorbent using
Soxhlet extraction as described in this paragraph (b). To accommodate
the Soxhlet extractions of all SVOCs from a single sample, two 16 hour
extractions are required. This will reduce the possibility of loss of
low molecular weight SVOCs and promote water removal. We recommend
performing the first extraction with acetone/hexane and the second
using toluene (or an equivalent solvent system).
    (1) We recommend equipping the Soxhlet extractor with a Dean-Stark
trap to facilitate the removal of residual water from the sample train
rinse. The Soxhlet apparatus must be large enough to allow extraction
of the PUF, XAD-2, and filter in a single batch. Include in the
extractor setup a glass thimble with a coarse or extra coarse sintered
glass bottom. Pre-clean the extractor using proper glass cleaning
procedures. We recommend that the Soxhlet apparatus be cleaned with a 4
to 8 hr Soxhlet extraction with methylene chloride at a cycling rate of
3 cycles per hour. Discard the solvent used for pre-cleaning (no
analysis is necessary).
    (2) Load the extractor thimble before placing it in the extractor
by first rolling the PM filter around the inner circumference of the
thimble with the sampled side facing in. Push one PUF plug down into
the bottom of the thimble then add approximately half of the XAD-2. The
then spike the XAD-2 in the thimble with the isotopically labeled
extraction standards of known mass. Target the center of the XAD-2 bed
for extraction standard delivery. We recommend using multiple
isotopically labeled extraction standards that cover the range of
target analytes. Generally this means that you should use isotopically
labeled standards at least for the lowest and highest molecular weight
analytes for each category of compounds (such as PAHs and dioxins).
These extraction standards monitor the efficiency of the extraction and
are also used to determine analyte concentrations after analysis. Upon
completion of spiking, add the remaining XAD-2 to the thimble followed
by the remaining PUF plug. Then place the thimble into the extractor.
    (3) For the initial extraction, combine the concentrated acetone
rinses (from the sample train in paragraph (a) of this section) with
enough hexane to bring the solvent volume up to the target level of 700
mL. Assemble the extractor and turn on the heating controls and cooling
water. Allow the sample to reflux for 16 hours with the rheostat
adjusted so that the extraction cycles at a rate of 3.0 0.5
cycles per hour. Drain the water from the Dean-Stark trap as it accrues
by opening the stopcock on the trap. Discard this water unless it is to
be analyzed. In most cases, any water present will be removed within
approximately 2 hours of the start of the extraction.
    (4) Upon completion of the initial extraction, remove the solvent
and concentrate it to 4.0 0.5 mL using a Kuderna-Danish
concentrator that includes a condenser such as a three-ball Snyder
column with venting dimples and graduated collection tube. The use of
this concentrator will minimize evaporative loss of lower molecular
weight analytes.
    (i) Rinse the round bottom flask of the extractor with 60 to 100 mL
of hexane and add the rinsate to this concentrated extract.
    (ii) Concentrate the mixture to 4 0.5 mL using a
Kuderna-Danish concentrator or similar concentration apparatus.
    (iii) Repeat paragraphs (b)(4)(i) and (ii) of this section 3 times
or as necessary, to remove all of the residual solvent from the
extractor round bottom flask, concentrating the final rinse to 4 0.5 mL.
    (5) For the second extraction, combine the toluene rinses (from the
sample train in paragraph (a) of this section) with any additional
toluene needed to bring the solvent volume up to the target level of
700 mL. As noted in this paragraph (a) of this section, you may need to
concentrate the rinse prior to addition to the extraction apparatus if
the rinse solvent volume is too large. Allow the sample to reflux for
16 hours with the rheostat adjusted so that the extraction cycles at a
rate of 3.0 0.5 cycles per hour. Although little or no
water should be present during this stage, check the Dean-Stark trap
during the first 2 hours of the extraction.
    (6) Upon completion of the second extraction, remove the solvent
and concentrate it to 4 0.5 mL as described in paragraph
(b)(4) of this section. Using hexane from paragraph (4) of this section
as the rinse solvent, effectively performs a solvent exchange of
toluene with hexane.
    (7) Combine the concentrated extract from paragraph (b)(4) of this
section with the concentrated extract from paragraph (b)(6) of this
section. Divide the extract into a number of fractions based on the
number of analyses to be performed. Perform the separate sample clean
up described in paragraph (c) of this section as needed for each
fraction.
    (c) Sample clean up. This paragraph (c) describes how to perform
sample cleaning to remove unwanted SVOCs (that is, those SVOCs which
you are not analyzing for) and solids from the sample extract before
analysis. This process, which is known as ``sample clean up, reduces
the potential for interference or co-elution of peaks during analytical
analysis. Before proceeding with the sample clean up, spike the extract
with an alternate standard that contains a known mass of isotopically
labeled compounds that are identical (with the exception of the
labeling) to the target analytes. The number of compounds that make up
the standard will be determined by the category of the target analyte
compounds (such as PAHs or dioxin). For example, PAHs require the use
of 4 compounds in the alternate standard to cover the 4 basic ring
structures of PAHs (2-ring, 3-ring, 4-ring, and 5-ring structures).
These alternate standards

are used to monitor the efficiency of the clean up procedure. Before
sample clean up, concentrate the fractionated sample to about 2 mL with
a Kuderna-Danish concentrator or rotary evaporator, and then transfer
the extract to an 8-mL test tube with hexane rinse. Concentrate to a
volume of about 1 mL using a Kuderna-Danish concentrator. Since there
are several column chromatographic cleanup options available, use good
engineering judgment to select one appropriate for your target
analytes. Note that these clean-up techniques generally remove
compounds based on their polarity. The clean up procedures given in
paragraphs (c)(1) and (2) of this section are examples of clean-up
techniques for PAHs and nitropolynuclear aromatic hydrocarbons (nPAHs).
    (1) PAH clean up. The following method is appropriate for cleaning
up extracts intended for analysis of PAHs:
    (i) Pack a glass gravity column (250 mm x 10 mm recommended) by
inserting a clean glass wool plug into the bottom of the column
followed by the addition of 10 grams of activated silica gel in
methylene chloride. Tap the column to settle the silica gel, and then
add a 1 cm layer of anhydrous sodium sulfate. Since variations among
batches of silica gel may affect the elution volume of the various PAH,
the volume of solvent required to completely elute all of the PAH must
be verified by the analyst. The weight of the silica gel can then be
adjusted accordingly.
    (ii) Elute the column with 40 mL of hexane. The rate for all
elutions should be about 2 mL/min and you may use dry air or
N2 to maintain the headspace slightly above atmospheric
pressure to increase the elution rate. Discard the eluate just prior to
exposure of the sodium sulfate layer to the air or N2,
transfer the 1 mL sample extract onto the column using two additional 2
mL rinses of hexane to complete the transfer. Just prior to exposure of
the sodium sulfate layer to the air or N2, begin elution of
the column with 25 mL of hexane followed by 25 mL of 40 volume %
methylene chloride in hexane. Collect the entire eluate and concentrate
it to about 5 mL using the Kuderna-Danish concentrator or a rotary
evaporator. Make sure that you do not evaporate all of the solvent from
the extract during the concentration process. Transfer to a small
sample vial using a hexane rinse and concentrate to 100 [mu]L using a
stream of nitrogen, gentle enough to not violently disturb the solvent.
Store the extracts in a refrigerator at 4 [deg]C or lower away from
light until analysis.
    (2) nPAH clean up. The following procedure, that was adapted from
``Determination and Comparison of Nitrated-Polycyclic Aromatic
Hydrocarbons Measured in Air and Diesel Particulate Reference
Materials'' (Bamford, H.A., et al, Chemosphere, Vol. 50, Issue 5, pages
575-587), is an appropriate method to clean up extracts intended for
analysis of nPAHs:
    (i) Condition an aminopropyl solid phase extraction (SPE) cartridge
by eluting it with 20 mL of 20 volume % methylene chloride in hexane
before use. Transfer the extract quantitatively to the SPE cartridge
with at least two methylene chloride rinsings. Elute the extract
through the SPE cartridge by using 40 ml of 20 volume % methylene
chloride in hexane to minimize potential interference of polar
constituents. Then reduce the extract to 0.5 ml in hexane and subject
the extract to normal-phase liquid chromatography using pre-prepared a
9.6 mm X 25 cm semi-preparative Chromegabond[supreg] amino/cyano
column, 5 [mu]m particle size to isolate the nPAH fraction. The mobile
phase is 20 volume % methylene chloride in hexane at a constant flow
rate of 5 ml/min. Prior to each injection, the column should be back
flashed with 60 ml of methylene chloride and then conditioned with 200
ml of 20 volume % methylene chloride in hexane. Collect the effluent
and concentrate to about 2 mL using the Kuderna-Danish concentrator or
a rotary evaporator. Transfer to a minivial using a hexane rinse and
concentrate to 100 [mu]L using a gentle stream of nitrogen. Store the
extracts at 4 [deg]C or lower away from light until analysis.
    (ii) [Reserved]

Sec.  1065.1111  Sample analysis.

    This subpart does not specify chromatographic or analytical methods
to analyze extracts, because the selection of such methods is highly
dependent on the nature of the target analytes. However, we recommend
that prior to whichever sample analysis you choose, you spike the
extract with an injection standard that contains a known mass of an
isotopically labeled compound that is identical (with the exception of
the labeling) to one of the target analytes. This injection standard is
used to monitor the efficiency of the analytical process by verifying
the volume of sample injected for analysis.
0
284. Part 1066 is revised to read as follows:

PART 1066--VEHICLE-TESTING PROCEDURES

Subpart A--Applicability and General Provisions
1066.1 Applicability.
1066.2 Submitting information to EPA under this part.
1066.5 Overview of this part 1066 and its relationship to the
standard-setting part.
1066.10 Other procedures.
1066.15 Overview of test procedures.
1066.20 Units of measure and overview of calculations.
1066.25 Recordkeeping.
Subpart B--Equipment, Measurement Instruments, Fuel, and Analytical Gas
Specifications
1066.101 Overview.
1066.105 Ambient controls and vehicle cooling fans.
1066.110 Equipment specifications for emission sampling systems.
1066.120 Measurement instruments.
1065.122 Data updating, recording, and control for measurement
instruments.
1066.130 Measurement instrument calibrations and verifications.
1066.137 Linearity verification.
1066.140 Diluted exhaust flow calibration.
1066.145 Engine fluids, test fuels, analytical gases, and other
calibration standards.
1066.150 Analyzer interference and quench verification limit.
Subpart C--Dynamometer Specifications
1066.201 Dynamometer overview.
1066.210 Dynamometers.
1066.215 Summary of verification and calibration procedures for
chassis dynamometers.
1066.220 Linearity verification for chassis dynamometer systems.
1066.225 Roll runout and diameter verification procedure.
1066.230 Time verification procedure.
1066.235 Speed verification procedure.
1066.240 Torque transducer calibration.
1066.245 Response time verification.
1066.250 Base inertia verification.
1066.255 Parasitic loss verification.
1066.260 Parasitic friction compensation evaluation.
1066.265 Acceleration and deceleration verification.
1066.270 Unloaded coastdown verification.
1066.280 Daily dynamometer readiness verification.
1066.290 Driver's aid.
Subpart D--Coastdown
1066.301 Overview of coastdown procedures.
1066.305 Coastdown procedures for motor vehicles at or below 14,000
pounds GVWR.
1066.310 Coastdown procedures for vehicles above 14,000 pounds GVWR.
1066.320 Dynamometer road-load setting.
Subpart E--Preparing Vehicles and Running an Exhaust Emission Test
1066.401 Overview.
1066.407 Vehicle preparation and preconditioning.

1066.410 Dynamometer test procedure.
1066.420 Vehicle operation.
1066.425 Test preparation.
1066.430 Performing emission tests.
Subpart F--Hybrids and Electric Vehicles
1066.501 Overview.
Subpart G--Calculations
1066.601 Overview.
1066.610 Mass-based and molar-based exhaust emission calculations.
1066.620 Dilution air background correction.
1066.630 NOX intake-air humidity correction.
1066.640 Removed water correction.
1066.650 Flow meter calibration calculations.
1066.652 PDP, SSV, and CFV flow rate calculations.
1066.665 NMOG determination.
1066.695 Data requirements.
Subpart H--Cold-Temperature Test Procedures
1066.701 Applicability and general provisions.
1066.710 Cold-testing procedures for measuring CO and NMHC emissions
and determining fuel economy.
Subpart I--Exhaust Emission Test Procedures for Motor Vehicles
1066.801 Applicability and general provisions.
1066.810 Road load power, test weight, and inertia weight class
determination.
1066.814 Vehicle preparation.
1066.820 Exhaust emission test procedures for FTP emissions.
1066.822 Composite calculations for FTP exhaust emissions.
1066.830 Supplemental Federal Test Procedures; overview.
1066.831 Exhaust emission test procedures for agressive driving.
1066.832 Exhaust emission test procedure for SC03 emissions.
1066.835 AC17 Air conditioning efficiency test procedure.
1066.839 Highway fuel economy test procedure.
1066.840 Fuel storage system leak test procedure.
Subpart J--[Reserved]
Subpart K--Definitions and Other Reference Material
1066.1001 Definitions.
1066.1005 Symbols, abbreviations, acronyms, and units of measure.
1066.1010 Reference materials.

    Authority: 42 U.S.C. 7401-7671q.

Subpart A--Applicability and General Provisions

Sec.  1066.1  Applicability.

    (a) This part describes the procedures that apply to testing we
require for the following vehicles:
    (1) Model year 2014 and later heavy-duty highway vehicles we
regulate under 40 CFR part 1037 that are not subject to chassis testing
for exhaust emissions under 40 CFR part 86.
    (2) Model year 2022 and later highway vehicles (light-duty and
heavy-duty) that are subject to chassis testing for exhaust emissions
under 40 CFR part 86. See 40 CFR part 86 for provisions describing how
to implement this part 1066.
    (b) The procedures of this part may apply to other types of
vehicles, as described in this part and in the standard-setting part.
    (c) The term ``you'' means anyone performing testing under this
part other than EPA.
    (1) This part is addressed primarily to manufacturers of vehicles,
but it applies equally to anyone who does testing under this part for
such manufacturers.
    (2) This part applies to any manufacturer or supplier of test
equipment, instruments, supplies, or any other goods or services
related to the procedures, requirements, recommendations, or options in
this part.
    (d) Paragraph (a) of this section identifies the parts of the CFR
that define emission standards and other requirements for particular
types of vehicles. In this part, we refer to each of these other parts
generically as the ``standard-setting part.'' For example, 40 CFR part
1037 is the standard-setting part for heavy-duty highway vehicles and
parts 86 and 600 are the standard-setting parts for light-duty
vehicles. For vehicles subject to 40 CFR part 86, subpart S, references
to the standard-setting part include subpart I of this part.
    (e) Unless we specify otherwise, the terms ``procedures'' and
``test procedures'' in this part include all aspects of vehicle
testing, including the equipment specifications, calibrations,
calculations, and other protocols and procedural specifications needed
to measure emissions.
    (f) For additional information regarding these test procedures,
visit our Web site at www.epa.gov, and in particular http://www.epa.gov/nvfel/testing/regulations.htm.

Sec.  1066.2  Submitting information to EPA under this part.

    (a) You are responsible for statements and information in your
applications for certification, requests for approved procedures,
selective enforcement audits, laboratory audits, production-line test
reports, or any other statements you make to us related to this part
1066. If you provide statements or information to someone for
submission to EPA, you are responsible for these statements and
information as if you had submitted them to EPA yourself.
    (b) In the standard-setting part and in 40 CFR 1068.101, we
describe your obligation to report truthful and complete information
and the consequences of failing to meet this obligation. See also 18
U.S.C. 1001 and 42 U.S.C. 7413(c)(2). This obligation applies whether
you submit this information directly to EPA or through someone else.
    (c) We may void any certificates or approvals associated with a
submission of information if we find that you intentionally submitted
false, incomplete, or misleading information. For example, if we find
that you intentionally submitted incomplete information to mislead EPA
when requesting approval to use alternate test procedures, we may void
the certificates for all engine families certified based on emission
data collected using the alternate procedures. This would also apply if
you ignore data from incomplete tests or from repeat tests with higher
emission results.
    (d) We may require an authorized representative of your company to
approve and sign the submission, and to certify that all the
information submitted is accurate and complete. This includes everyone
who submits information, including manufacturers and others.
    (e) See 40 CFR 1068.10 for provisions related to confidential
information. Note however that under 40 CFR 2.301, emission data are
generally not eligible for confidential treatment.
    (f) Nothing in this part should be interpreted to limit our ability
under Clean Air Act section 208 (42 U.S.C. 7542) to verify that
vehicles conform to the regulations.

Sec.  1066.5  Overview of this part 1066 and its relationship to the
standard-setting part.

    (a) This part specifies procedures that can apply generally to
testing various categories of vehicles. See the standard-setting part
for directions in applying specific provisions in this part for a
particular type of vehicle. Before using this part's procedures, read
the standard-setting part to answer at least the following questions:
    (1) What drive schedules must I use for testing?
    (2) Should I warm up the test vehicle before measuring emissions,
or do I need to measure cold-start emissions during a warm-up segment
of the duty cycle?
    (3) Which exhaust constituents do I need to measure? Measure all
exhaust constituents that are subject to emission standards, any other
exhaust

constituents needed for calculating emission rates, and any additional
exhaust constituents as specified in the standard-setting part. See 40
CFR 1065.5 regarding requests to omit measurement of N2O and
CH4 for vehicles, not subject to N2O or
CH4 emission standards.
    (4) Do any unique specifications apply for test fuels?
    (5) What maintenance steps may I take before or between tests on an
emission-data vehicle?
    (6) Do any unique requirements apply to stabilizing emission levels
on a new vehicle?
    (7) Do any unique requirements apply to test limits, such as
ambient temperatures or pressures?
    (8) [Reserved]
    (9) Are there any emission standards specified at particular
operating conditions or ambient conditions?
    (10) Do any unique requirements apply for durability testing?
    (b) The testing specifications in the standard-setting part may
differ from the specifications in this part. In cases where it is not
possible to comply with both the standard-setting part and this part,
you must comply with the specifications in the standard-setting part.
The standard-setting part may also allow you to deviate from the
procedures of this part for other reasons.
    (c) The following table shows how this part divides testing
specifications into subparts:

      Table 1 of Sec.   1066.5--Description of Part 1066 Subparts.
------------------------------------------------------------------------
                                     Describes these specifications or
           This subpart                          procedures
------------------------------------------------------------------------
Subpart A........................  Applicability and general provisions.
Subpart B........................  Equipment for testing.
Subpart C........................  Dynamometer specifications.
Subpart D........................  Coastdowns for testing.
Subpart E........................  How to prepare your vehicle and run
                                    an emission test.
Subpart F........................  How to test hybrid vehicles.
Subpart G........................  Test procedure calculations.
Subpart H........................  Cold temperature testing.
Subpart I........................  Exhaust emission test procedures for
                                    motor vehicles.
Subpart J........................  Reserved.
Subpart K........................  Definitions and reference material.
------------------------------------------------------------------------

Sec.  1066.10  Other procedures.

    (a) Your testing. The procedures in this part apply for all testing
you do to show compliance with emission standards, with certain
exceptions noted in this section. In some other sections in this part,
we allow you to use other procedures (such as less precise or less
accurate procedures) if they do not affect your ability to show that
your vehicles comply with the applicable emission standards. This
generally requires emission levels to be far enough below the
applicable emission standards so that any errors caused by greater
imprecision or inaccuracy do not affect your ability to state
unconditionally that the engines meet all applicable emission
standards.
    (b) Our testing. These procedures generally apply for testing that
we do to determine if your vehicles comply with applicable emission
standards. We may perform other testing as allowed by the Act.
    (c) Exceptions. We may allow or require you to use procedures other
than those specified in this part as described in 40 CFR 1065.10(c).
All the test procedures noted as exceptions to the specified procedures
are considered generically as ``other procedures.'' Note that the terms
``special procedures'' and ``alternate procedures'' have specific
meanings; ``special procedures'' are those allowed by 40 CFR
1065.10(c)(2) and ``alternate procedures'' are those allowed by 40 CFR
1065.10(c)(7). If we require you to request approval to use other
procedures under this paragraph (c), you may not use them until we
approve your request.

Sec.  1066.15  Overview of test procedures.

    This section outlines the procedures to test vehicles that are
subject to emission standards.
    (a) In the standard-setting part, we set emission standards in g/
mile (or g/km), for the following constituents:
    (1) Total oxides of nitrogen, NOX.
    (2) Hydrocarbons, HC, which may be expressed in the following ways:
    (i) Total hydrocarbons, THC.
    (ii) Nonmethane hydrocarbons, NMHC, which results from subtracting
methane (CH4) from THC.
    (iii) Total hydrocarbon-equivalent, THCE, which results from
adjusting THC mathematically to be equivalent on a carbon-mass basis.
    (iv) Nonmethane hydrocarbon-equivalent, NMHCE, which results from
adjusting NMHC mathematically to be equivalent on a carbon-mass basis.
    (v) Nonmethane organic gases, NMOG, which are calculated either
from fully or partially speciated measurement of hydrocarbons including
oxygenates, or by adjusting measured NMHC values based on fuel
oxygenate properties.
    (3) Particulate mass, PM.
    (4) Carbon monoxide, CO.
    (5) Carbon dioxide, CO2.
    (6) Methane, CH4.
    (7) Nitrous oxide, N2O.
    (8) Formaldehyde, CH2O.
    (b) Note that some vehicles may not be subject to standards for all
the emission constituents identified in paragraph (a) of this section.
Note also that the standard-setting part may include standards for
pollutants not listed in paragraph (a) of this section.
    (c) The provisions of this part apply for chassis dynamometer
testing where vehicle speed is controlled to follow a prescribed duty
cycle while simulating vehicle driving through the dynamometer's road-
load settings. We generally set emission standards over test intervals
and/or drive schedules, as follows:
    (1) Vehicle operation. Testing involves measuring emissions and
miles travelled while operating the vehicle on a chassis dynamometer.
Refer to the definitions of ``duty cycle'' and ``test interval'' in
Sec.  1066.1001. Note that a single drive schedule may have multiple
test intervals and require weighting of results from multiple test
intervals to calculate a composite distance-based emission value to
compare to the standard.
    (2) Constituent determination. Determine the total mass of each
constituent over a test interval by selecting from the following
methods:
    (i) Continuous sampling. In continuous sampling, measure the
constituent's concentration continuously from raw or dilute exhaust.
Multiply this concentration by the continuous (raw or dilute) flow rate
at the emission sampling location to determine the constituent's flow
rate. Sum the constituent's flow rate continuously over the test
interval. This sum is the total mass of the emitted constituent.
    (ii) Batch sampling. In batch sampling, continuously extract and
store a sample of raw or dilute exhaust for later measurement. Extract
a sample proportional to the raw or dilute exhaust flow rate, as
applicable. You may extract and store a proportional sample of exhaust
in an appropriate container, such as a bag, and then measure HC, CO,
and NOX concentrations in the container after the test
interval. You may deposit PM from proportionally extracted exhaust onto
an appropriate substrate, such as a filter. In this case, divide the PM
by the amount of filtered exhaust to calculate the PM concentration.
Multiply batch sampled concentrations by the total (raw or dilute) flow
from which it was extracted during the test interval. This product is
the total mass of the emitted constituent.
    (iii) Combined sampling. You may use continuous and batch sampling
simultaneously during a test interval, as follows:

    (A) You may use continuous sampling for some constituents and batch
sampling for others.
    (B) You may use continuous and batch sampling for a single
constituent, with one being a redundant measurement, subject to the
provisions of 40 CFR 1065.201.
    (d) Refer to the standard-setting part for calculations to
determine g/mile emission rates.
    (e) You must use good engineering judgment for all aspects of
testing under this part. While this part highlights several specific
cases where good engineering judgment is especially relevant, the
requirement to use good engineering judgment is not limited to those
provisions where we specifically re-state this requirement.

Sec.  1066.20  Units of measure and overview of calculations.

    (a) System of units. The procedures in this part follow both
conventional English Units and the International System of Units (SI),
as detailed in NIST Special Publication 811, which we incorporate by
reference in Sec.  1066.1010. Except where specified, equations work
with any system of units. Where the equations depend on the use of
specific units, these units are identified.
    (b) Units conversion. Use good engineering judgment to convert
units between measurement systems as needed. For example, if you
measure vehicle speed as kilometers per hour and we specify a precision
requirement in terms of miles per hour, convert your measured kilometer
per hour value to miles per hour before comparing it to our
specification. The following conventions are used throughout this
document and should be used to convert units as applicable:
    (1) 1 hp = 33,000 ft[middot]lbf/min = 550 ft[middot]lbf/s = 0.7457
kW.
    (2) 1 lbf = 32.174 ft[middot]lbm/s\2\ = 4.4482 N.
    (3) 1 inch = 25.4 mm.
    (4) 1 mile = 1609.344 m.
    (5) For ideal gases, 1 [micro]mol/mol = 1 ppm.
    (6) For ideal gases, 10 mmol/mol = 1%.
    (c) Temperauture. We generally designate temperatures in units of
degrees Celsius ([deg]C) unless a calculation requires an absolute
temperature. In that case, we designate temperatures in units of Kelvin
(K). For conversion purposes throughout this part, 0 [deg]C equals
273.15 K. Unless specified otherwise, always use absolute temperature
values for multiplying or dividing by temperature.
    (d) Absolute pressure. Measure absolute pressure directly or
calculate it as the sum of atmospheric pressure plus a differential
pressure that is referenced to atmospheric pressure. Always use
absolute pressure values for multiplying or dividing by pressure.
    (e) Rounding. The rounding provisions of 40 CFR 1065.20 apply for
calculations in this part. This generally specifies that you round
final values but not intermediate values. Use good engineering judgment
to record the appropriate number of significant digits for all
measurements.
    (f) Interpretation of ranges. Interpret a range as a tolerance
unless we explicitly identify it as an accuracy, repeatability,
linearity, or noise specification. See 40 CFR 1065.1001 for the
definition of tolerance. In this part, we specify two types of ranges:
    (1) Whenever we specify a range by a single value and corresponding
limit values above and below that value (such as X Y),
target the associated control point to that single value (X). Examples
of this type of range include ``10% of maximum pressure'',
or ``(30 10) kPa''. In these examples, you would target the
maximum pressure or 30 kPa, respectively.
    (2) Whenever we specify a range by the interval between two values,
you may target any associated control point to any value within that
range. An example of this type of range is ``(40 to 50) kPa''.
    (g) Scaling of specifications with respect to an applicable
standard. Because this part 1066 applies to a wide range of vehicles
and emission standards, some of the specifications in this part are
scaled with respect to a vehicle's applicable standard or weight. This
ensures that the specification will be adequate to determine
compliance, but not overly burdensome by requiring unnecessarily high-
precision equipment. Many of these specifications are given with
respect to a ``flow-weighted mean'' that is expected at the standard or
during testing. Flow-weighted mean is the mean of a quantity after it
is weighted proportional to a corresponding flow rate. For example, if
a gas concentration is measured continuously from the raw exhaust of an
engine, its flow-weighted mean concentration is the sum of the products
of each recorded concentration times its respective exhaust flow rate,
divided by the sum of the recorded flow rates. As another example, the
bag concentration from a CVS system is the same as the flow-weighted
mean concentration, because the CVS system itself flow-weights the bag
concentration.

Sec.  1066.25  Recordkeeping.

    The procedures in this part include various requirements to record
data or other information. Refer to the standard-setting part and Sec.
1066.695 regarding recordkeeping requirements. You must promptly send
us organized, written records in English if we ask for them. We may
review them at any time.

Subpart B--Equipment, Measurement Instruments, Fuel, and Analytical
Gas Specifications

Sec.  1066.101  Overview.

    (a) This subpart addresses equipment related to emission testing,
as well as test fuels and analytical gases. This section addresses
emission sampling and analytical equipment, test fuels, and analytical
gases.
    (b) The provisions of 40 CFR part 1065 specify engine-based
procedures for measuring emissions. Except as specified otherwise in
this part, the provisions of 40 CFR part 1065 apply for testing
required by this part as follows:
    (1) The provisions of 40 CFR part 1065, subpart B, describe
equipment specifications for exhaust dilution and sampling systems;
these specifications apply for testing under this part as described in
Sec.  1066.110.
    (2) The provisions of 40 CFR part 1065, subpart C, describe
specifications for measurement instrument; these specifications apply
for testing under this part as described in Sec.  1066.120.
    (3) The provisions of 40 CFR part 1065, subpart D, describe
specifications for measurement instrument calibrations and
verifications; these specifications apply for testing under this part
as described in Sec.  1066.130.
    (4) The provisions of 40 CFR part 1065, subpart H, describe
specifications for fuels, engine fluids, and analytical gases; these
specifications apply for testing under this part as described in Sec.
1066.145.
    (5) The provisions of 40 CFR part 1065, subpart I, describe
specifications for testing with oxygenated fuels; these specifications
apply for NMOG determinations as described in Sec.  1066.665.
    (c) The provisions of this subpart are intended to specify systems
that can very accurately and precisely measure emissions from motor
vehicles such as light-duty vehicles. To the extent that this level of
accuracy and/or precision is not necessary for testing highway
motorcycles or nonroad vehicles, we may waive or modify the
specifications and requirements of this part for testing these other
vehicles, consistent with good engineering judgment. For example, it
may be appropriate to allow the use of a hydrokinetic dynamometer that
is not able to meet all the

performance specifications described in this subpart.

Sec.  1066.105  Ambient controls and vehicle cooling fans.

    (a) Ambient conditions. Dynamometer testing under this part
generally requires that you maintain the test cell within a specified
range of ambient temperature and humidity. Use good engineering
judgment to maintain relatively uniform temperatures throughout the
test cell before testing. You are generally not required to maintain
uniform temperatures throughout the test cell while the vehicle is
running due to the heat generated by the vehicle. Measured humidity
values must accurately represent the humidity of intake air; other than
the intake air, humidity does not affect emissions so humidity need not
be uniform throughout the test cell.
    (b) General requirements for cooling fans. Use good engineering
judgment to select and configure fans to cool the test vehicle in a way
that meets the specifications of paragraph (c) of this section and
simulates in-use operation. If you demonstrate that the specified fan
configuration is impractical for special vehicle designs, such as
vehicles with rear-mounted engines, or it does not provide adequate
cooling to properly represent in-use operation, you may ask us to
approve increasing the fan's capacity or using additional fans.
    (c) Allowable cooling fans for vehicles at or below 14,000 pounds
GVWR. Cooling fan specifications for vehicles at or below 14,000 pounds
GVWR depend on the test cycle. Paragraph (c)(1) of this section
summarizes the cooling fan specifications for the different test
cycles; the detailed specifications are described in paragraphs (c)(2)
through (5) of this section. See Sec.  1066.410 for instruction
regarding how to use the fans during testing.
    (1) Cooling fan specifications for different test cycles are
summarized as follows:
    (i) For FTP and LA-92 test cycles, the allowable cooling fan
configurations are described in paragraphs (c)(2) and (4) of this
section.
    (ii) For the US06 test cycle, the allowable cooling fan
configurations are described in paragraphs (c)(2) and (5) of this
section. The cooling fan configuration in paragraph (c)(4) of this
section is also allowable with advance approval.
    (iii) For SC03 and AC17 test cycles, the allowable cooling fan
configuration is described in paragraph (c)(3) of this section.
    (iv) For the HFET test cycle, the allowable cooling fan
configurations are described in paragraphs (c)(2) and (4) of this
section.
    (2) You may use a road-speed modulated fan system meeting the
specifications of this paragraph (c)(2) for anything other than SC03
and AC17 testing. Use a road-speed modulated fan that achieves a linear
speed of cooling air at the blower outlet that is within 3.0 mph (1.3 m/s) of the corresponding roll speed
when vehicle speeds are between 5 and 30 mph (2.2 to 13.4 m/s), and
within 6.5 mph (2.9 m/s) of the corresponding
roll speed at higher vehicle speeds; however you may limit the fan's
maximum linear speed to 70 mph. We recommend that the cooling fan have
a minimum opening of 0.2 m\2\ and a minimum width of 0.8 m.
    (i) Verify the air flow velocity for fan speed corresponding to
vehicle speeds of 20 and 40 mph using an instrument that has an
accuracy of 2% of the measured air flow speed.
    (ii) For fans with rectangular outlets, divide the fan outlet into
the as shown in Figure 1 of this section. As denoted by the ``+'' in
the figure, measure flow from the center of each section; however do
not measure the flow from the center section.
[GRAPHIC] [TIFF OMITTED] TP21MY13.041

    (iii) For fans with circular outlets, divide the fan outlet into 8
equal sections as shown in Figure 2 of this section. As denoted by the
``+'' in the figure, measure flow on the radial centerline of each
section (at 22.5[deg]) at a radius of two-thirds of the total radius.

[GRAPHIC] [TIFF OMITTED] TP21MY13.042

    (iv) Verify that the fan air flow velocity vector perpendicular to
the axial flow velocity vector is less than 15% of the mean velocity
measured at fan speeds corresponding to vehicle speeds of 20 and 40
mph.
    (v) Verify that the uniformity of the fan axial flow tolerance is
within 4.0 mph at fan speeds corresponding to 20 mph and
within 8.0 mph at fan speeds corresponding to 40 mph. For
example, at 20 mph, flow at all axial locations denoted by the ``+''
across the discharge nozzle must be between 16 and 24 mph. Measure the
fan axial air flow velocity 60 cm from the nozzle outlet at each point
of the discharge area grid.
    (3) For SC03 and AC17 testing, use a road-speed modulated fan with
a minimum air flow nozzle discharge area that is equal to or exceeds
the vehicle's frontal inlet area. We recommend using a fan with a
discharge area of 1.7 m\2\.
    (i) Air flow volumes must be proportional to vehicle speed. When
meeting the minimum discharge area requirements, the flow volume would
vary from 0 m\3\/s at 0 mph to approximately 450 m\3\/s at 60 mph. If
this fan is also the only source of test cell air circulation or if fan
operational mechanics make the 0 mph air flow requirement impractical,
air flow of 2 mph or less at 0 mph vehicle speed is allowed.
    (ii) Verify that the fan air flow velocity vector perpendicular to
the axial flow velocity vector is less than 10% of the mean velocity
measured at fan speeds corresponding to vehicle speeds between 20 and
40 mph.
    (iii) Verify that the uniformity of fan axial flow tolerance is 20%
of the fan speed corresponding to vehicle speeds of 20 and 40 mph. For
example, at 20 mph, flow at all axial locations across the discharge
nozzle must be between 16 and 24 mph. Measure the fan axial air flow
velocity 60 cm from the nozzle outlet at each point of the discharge
area grid.
    (iv) The instrument used to verify the air velocity must have an
accuracy of 2% of the measured air flow speed.
    (v) In addition to the road-speed modulated fan, we may approve the
use of one or more fixed-speed fans to provide proper cooling to
represent in-use operation, but only up to a total of 2.50 m\3\/s for
all additional fans.
    (4) You may use a fixed-speed fan with a maximum capacity up to
2.50 m\3\/s for FTP, LA-92, and HFET testing.
    (5) You may use a fixed-speed fan with a maximum capacity up to
7.10 m\3\/s for US06 testing.
    (d) Allowable cooling fans for vehicles above 14,000 pounds GVWR.
For all testing, use a road-speed modulated fan system that achieves a
linear speed of cooling air at the blower outlet that is within 3.0 mph (1.3 m/s) of the corresponding roll speed
when vehicle speeds are between 5 and 30 mph (2.2 to 13.4 m/s), and
within 10 mph (4.5 m/s) of the corresponding
roll speed at higher vehicle speeds. For vehicles above 19,500 pounds
GVWR, we recommend that the cooling fan have a minimum opening of 2.75
m\2\, a minimum flow rate of 60 m\3\/s at 50 mph, and a minimum speed
profile across the duct, in the free stream flow, that is 15% of the target flow rate.

Sec.  1066.110  Equipment specifications for emission sampling systems.

    (a) This section specifies equipment related to emission testing,
other than measurement instruments. This equipment includes two broad
categories--dynamometers (described further in subpart C of this part)
and emission-sampling hardware. Other related sections in this subpart
identify measurement instruments (Sec.  1066.120), describe how to
evaluate the performance of these instruments (Sec. Sec.  1066.130 and
1066.137), describe how to calibrate a CVS (Sec.  1066.140), specify
engine fluids and analytical gases (Sec.  1066.145), and specify
requirements for analyzer interference and quench verification (Sec.
1066.150).
    (b) The following equipment specifications apply for testing under
this part:
    (1) Tailpipe connections. Connect a vehicle's exhaust system to any
dilution stage as follows:
    (i) Minimize laboratory exhaust tubing lengths. You may use a total
length of laboratory tubing up to 4 m, without needing to heat or
insulate the tubing. However, you may use a total length of laboratory
tubing up to 10 m if you insulate and/or heat the tubing to minimize
the temperature difference between the exhaust gas and the tubing wall
over the course of the emission test. The laboratory exhaust tubing
starts at the end of the vehicle's tailpipe. The laboratory exhaust
tubing ends at the first sample point or the point of first dilution.
You may use flexible laboratory exhaust tubing at any location in the
laboratory exhaust system, although we recommend that you limit the
amount of flexible tubing to the extent practicable. For multiple-
tailpipe configurations where the tailpipes combine into a single flow
path for emission sampling, the start of the laboratory exhaust tubing
may be taken at the last joint where the exhaust flow first becomes a
single, combined flow.
    (ii) You may insulate or heat any laboratory exhaust tubing.
    (iii) Use laboratory exhaust tubing materials that are smooth-
walled and not chemically reactive with exhaust constituents. (For
purposes of this paragraph (b)(1), nominally smooth spiral-style and
accordion-style flexible tubing are considered to be smooth-walled.)
For measurements involving

PM, tubing materials must also be electrically conductive. Stainless
steel is an acceptable material for any measurements. You may use short
sections of nonconductive flexible tubing to connect a PM sampling
system to the vehicle's tailpipe; use good engineering judgment to
limit the amount of nonconductive surface area exposed to the vehicle's
exhaust.
    (iv) We recommend that you use laboratory exhaust tubing that has
either a wall thickness of less than 2 mm or is air gap-insulated to
minimize temperature differences between the wall and the exhaust.
    (v) You must seal your system to the extent necessary to ensure
that any remaining leaks do not affect your ability to demonstrate
compliance with the applicable standards. We recommend that you seal
all known leaks.
    (vi) Electrically ground the entire exhaust system, with the
exception of nonconductive flexible tubing, as allowed under paragraph
(b)(1)(iii) of this section.
    (vii) For vehicles with multiple tailpipes, route the exhaust into
a single flow. To ensure mixing of the multiple exhaust streams before
emission sampling, you may configure the exhaust system with turbulence
generators, such as orifice plates or fins, to achieve good mixing. We
recommend a minimum Reynolds number, Re, of 4000 for the
combined exhaust stream, where Re is based on the inside
diameter of the combined flow at the first sampling point. Re
is defined in 40 CFR 1065.640.
    (2) Provisions from 40 CFR part 1065. Use equipment specifications
in 40 CFR 1065.140 through 40 CFR 1065.190, except as follows:
    (i) For PM background measurement, the following provisions apply
instead of the analogous provisions in 40 CFR 1065.140(b):
    (A) You need not measure PM background for every test. You may
apply PM background correction using a moving-average background value
as long as your background PM sample media (e.g., filters) were all
made by the same manufacturer from the same material. Use good
engineering judgment to determine how many background samples make up
the moving average and how frequently to update those values. For
example, you might take one background sample per week and average that
sample into previous background values, maintaining five observations
for each calculated average value. Background sampling time should be
representative of the test interval duration to which the background
correction is applied.
    (B) You may sample background PM from the dilution tunnel at any
time before or after an emission test using the same sample train used
during the emission test. For this background sampling, the dilution
tunnel blower must be turned on, the vehicle must be disconnected from
the exhaust transfer tube, and the exhaust transfer tube must be
capped.
    (C) The duration of your background sample does not need to be the
same as the test cycle in which you are applying the background
correction, provided it is not inconsistent with the use of good
engineering judgment.
    (D) Your background correction may not exceed 5 [micro]g or 5% of
the net PM mass expected at the standard, whichever allowance is
greater.
    (ii) The provisions of 40 CFR 1065.140(d)(2)(iv) do not apply.
    (iii) For PM samples, configure dilution systems using the
following limits:
    (A) Control the dilution air temperature as described in 40 CFR
1065.140(e)(1), except that the temperature may set to (15 to 52)
[deg]C. Use good engineering judgment to control PM sample temperature
as required under 40 CFR 1065.140(e)(4).
    (B) Apply the provisions of this paragraph (b)(2)(iii)(B) instead
of 40 CFR 1065.140(e)(2). Add dilution air to the raw exhaust such that
the overall dilution factor of diluted exhaust to raw exhaust, as
determined in Eq. 1066.620-2 or 1066.620-3, is within the range of (7:1
to 20:1). Compliance with this dilution factor range may be determined
for an individual test interval or as a time-weighted average over the
entire duty cycle as determined in Eq. 1066.620-4. The maximum dilution
factor limit of 20:1 does not apply for plug-in hybrid electric
vehicles (PHEVs) and hybrid electric vehicles (HEVs), since the
dilution factor is infinite when the engine is off; however we strongly
recommend that you stay under the maximum dilution factor limit when
the engine is running. For partial-flow sampling systems, determine
dilution factor using Eq. 1066.620-3. When determining dilution factor
for PM samples utilizing secondary dilution air, multiply the dilution
factor by the dilution ratio of secondary dilution air to primary
diluted exhaust.
    (iv) In addition to the allowances in 40 CFR 1065.140(c)(6) you may
also heat the dilution air as described in paragraph (b)(2)(iii)(A) of
this section to prevent or limit aqueous condensation.
    (v) If you choose to dilute the exhaust by using a remote mix tee,
which dilutes the exhaust at the tailpipe, you may use the following
provisions consistent with good engineering judgment, provided they do
not affect your ability to demonstrate compliance with the standard:
    (A) You may use accordion-style or smooth-walled flexible tubing in
the dilution tunnel upstream of flow or gaseous emission measurement
locations.
    (B) You may use smooth-walled electrically conductive flexible
tubing in the dilution tunnel upstream of where PM emission
measurements are made.
    (C) Materials for inside surfaces are limited to 300 series
stainless steel and polymer-based materials.
    (D) Use good engineering judgment to ensure that the materials you
choose do not cause or contribute to significant loss of PM from your
sample.
    (vi) Paragraph (b)(1)(vi) of this section applies instead of 40 CFR
1065.145(b).
    (c) The following table summarizes the requirements of paragraph
(b)(2) of this section:

 Table 1 of Sec.   1066.110--Summary of Equipment Specifications From 40
        CFR Part 1065, Subpart B, That Apply for Chassis Testing
------------------------------------------------------------------------
                                      Applicability for chassis testing
    40 CFR part 1065 references                under this part
------------------------------------------------------------------------
40 CFR 1065.140...................  Use all except:
                                       40 CFR 1065.140(b) applies as
                                        described in this section.
                                       Use 40 CFR 1065.140(c)(6), with
                                        the additional allowance
                                        described in this section.
                                       Do not use 40 CFR
                                        1065.140(d)(2)(iv).
                                       Use 40 CFR 1065.140(e)(1) as
                                        described in this section.
                                       Do not use 40 CFR 1065.140(e)(2).
40 CFR 1065.145...................  Use all except 40 CFR 1065.145(b).
40 CFR 1065.150 through 1065.190..  Use all.
------------------------------------------------------------------------

Sec.  1066.120  Measurement instruments.

    The measurement instrument requirements in 40 CFR part 1065,
subpart C, apply with the following exceptions:
    (a) The provisions of Sec.  1066.122 apply instead of 40 CFR
1065.202.
    (b) The provisions of 40 CFR 1065.210 and 1065.295 do not apply.

Sec.  1066.122  Data updating, recording, and control for measurement
instruments.

    This section specifies criteria that your test system must meet for
updating and recording data. It also specifies criteria for controlling
the systems related to driver demand, the dynamometer, sampling
equipment, and measurement instruments.
    (a)(1) This paragraph (a)(1) applies where we specify a minimum
command and control frequency that is greater than the minimum
recording frequency, such as for sample flow rates from a CVS that does
not have a heat exchanger. For these measurements, the rate at which
you read and interpret the signal must be at least as frequent as the
minimum command and control frequency. Values may be recorded at the
same frequency. They may also be recorded as means of the values,
provided the frequency of the mean values meets the minimum recording
frequency. All values read must be either recorded or used to calculate
the mean values. For example, if your system reads and controls the
sample flow rate at 10 Hz, you may record these values at 10 Hz, record
them at 5 Hz by averaging pairs of consecutive points together, or
record them at 1 Hz by averaging five consecutive points together.
    (2) For all other measured values covered by this section, you may
record the values instantaneously or as mean values, consistent with
good engineering judgment.
    (3) You may not use rolling averages of measured values where a
given measured value is included in more than one recorded mean value.
    (b) Use data acquisition and control systems that can command,
control, and record at the following minimum frequencies:

                   Table 1 of Sec.   1066.122--Data Recording and Control Minimum Frequencies
----------------------------------------------------------------------------------------------------------------
                                                    Minimum  command
     Applicable section          Measured values       and control          Minimum recording frequency \a\
                                                        frequency
----------------------------------------------------------------------------------------------------------------
Sec.   1066.310.............  Vehicle speed.......  ................  10 Hz.
Sec.   1066.320.............
Sec.   1066.430.............  Continuous            ................  1 Hz.
                               concentrations of
                               raw or dilute
                               analyzers.
Sec.   1066.430.............  Power analyzer \b\..  ................  1 Hz.
Sec.   1066.501.............
Sec.   1066.430.............  Bag concentrations    ................  1 mean value per test interval.
                               of raw or dilute
                               analyzers.
40 CFR 1065.545.............  Diluted exhaust flow  ................  1 Hz.
Sec.   1066.430.............   rate from a CVS
                               with a heat
                               exchanger upstream
                               of the flow
                               measurement.
40 CFR 1065.545.............  Diluted exhaust flow  N/A.............  1 Hz means.
Sec.   1066.430.............   rate from a CVS
                               without a heat
                               exchanger upstream
                               of the flow
                               measurement.
40 CFR 1065.545.............  Dilution air flow if  5 Hz............  1 Hz means.
Sec.   1066.430.............   actively controlled
                               (for example, a
                               partial-flow PM
                               sampling system).
40 CFR 1065.545.............  Sample flow from a    1 Hz............  1 Hz.
Sec.   1066.430.............   CVS that has a heat
                               exchanger.
40 CFR 1065.545.............  Sample flow from a    5 Hz............  1 Hz means.
Sec.   1066.430.............   CVS that does not
                               have a heat
                               exchanger.
Sec.   1066.425.............  Ambient temperature.  ................  1 Hz.
Sec.   1066.425.............  Ambient humidity....  ................  1 Hz.
Sec.   1066.425.............  Heated sample system  ................  1 Hz.
                               temperatures,
                               including PM filter
                               face.
----------------------------------------------------------------------------------------------------------------
\a\ 1 Hz means are data reported from the instrument at a higher frequency, but recorded as a series of mean
  values at a rate of 1 Hz.
\b\ For power analyzers' sampling frequency, follow SAE J1711 (incorporated by reference in Sec.   1066.1010).

Sec.  1066.130  Measurement instrument calibrations and verifications.

    The measurement instrument calibration and verification
requirements in 40 CFR part 1065, subpart D, apply with the following
exceptions:
    (a) The calibration and verification provisions of 40 CFR 1065.303
do not apply for engine speed, torque, fuel rate, or intake air flow.
Section 1066.133 specifies additional calibration and verification
provisions that apply specifically for chassis testing.
    (b) The linearity verification provisions of 40 CFR 1065.307 do not
apply for engine speed, torque, fuel rate, or intake air flow. Section
1066.137 specifies additional linearity verification provisions that
apply specifically for chassis testing.
    (c) The provisions of Sec.  1066.220 apply instead 40 CFR 1065.310.
    (d) The provisions of 40 CFR 1065.320, 1065.325, and 1065.395 do
not apply.
    (e) If you are measuring flow volumetrically (rather than by
molar), the provisions of Sec.  1066.140 apply instead of 40 CFR
1065.340.
    (f) The provisions of Sec.  1066.150 apply instead 40 CFR
1065.350(c), 1065.355(c), 1065.370(c), and 1065.375(c).
    (g) Table 1 of this section summarizes the required and recommended
calibrations and verifications that are unique to testing under this
part and indicates when these have to be performed. Perform other
required or recommended calibration and verifications as described in
40 CFR 1065.303, with the exceptions noted in this section. Table 1
follows:

     Table 1 of Sec.   1066.130-Summary of Required Calibration and
                              Verifications
------------------------------------------------------------------------
      Type of calibration or
           verification                     Minimum frequency \a\
------------------------------------------------------------------------
40 CFR 1065.303: Flow rates.......  This calibration does not apply for
                                     testing under this part; see Sec.
                                     1066.133 for alternative
                                     provisions.
40 CFR 1065.307: Linearity          The linearity calibrations from 40
 verification.                       CFR part 1065 do not apply under
                                     this part for engine speed, torque,
                                     fuel rate, or intake air flow; the
                                     linearity verification described in
                                     Sec.   1066.137 applies for the
                                     following measurements:
                                    Dynamometer Speed: See Sec.
                                     1066.220.
                                    Dynamometer Torque: See Sec.
                                     1066.220.
40 CFR 1065.310: Torque...........  This calibration does not apply for
                                     testing under this part; see Sec.
                                     1066.220.
40 CFR 1065.320: Fuel flow........  This calibration does not apply for
                                     testing under this part.
40 CFR 1065.325: Intake flow......  This calibration does not apply for
                                     testing under this part.
40 CFR 1065.340: CVS calibration..  This calibration does not apply for
                                     CVS flow meters calibrated
                                     volumetrically as described in Sec.
                                       1066.140.
40 CFR 1065.345: Vacuum leak......  Required upon initial installation
                                     of the sampling system; recommended
                                     within 35 days before the start of
                                     an emissions test and after
                                     maintenance such as pre-filter
                                     changes.
40 CFR 1065.350(c), 1065.355(c),    These provisions do not apply for
 1065.370(c), and 1065.375(c).       testing under this part; see Sec.
                                     1066.150.
40 CFR 1065.395: Inertial PM        These verifications do not apply for
 balance and weighing.               testing under this part.
------------------------------------------------------------------------
\a\ Perform calibrations and verifications more frequently if needed to
  conform to the measurement system manufacturer's instructions and good
  engineering judgment.

Sec.  1066.137  Linearity verification.

    This section describes requirements for linearity verification that
are unique to testing under this part. (Note: see the definition of
``linearity'' in 40 CFR 1065.1001, where we explain that linearity
means the degree to which measured values agree with respective
reference values and that the term ``linearity'' is not used to refer
to the shape of a measurement instrument's unprocessed response curve.)
Perform other required or recommended calibration and verifications as
described in 40 CFR 1065.307, with the exceptions noted in this
section.
    (a) For testing under this subpart, linearity verification under 40
CFR part 1065 is not required for speed, torque, fuel flow rate, or
intake air flow.
    (b) For gas analyzer linearity, use one of the following options:
    (1) Use instrument manufacturer recommendations and good
engineering judgment to select at least ten reference values,
yrefi, that cover the range of values that you expect during
testing (to prevent extrapolation beyond the verified range during
emission testing). We recommend selecting zero as one of your reference
values. For each range calibrated, if the deviation from a least-
squares best-fit straight line is 2% or less of the value at each data
point, concentration values may be calculated by use of a single
calibration factor for that range. If the deviation exceeds 2% at any
point, use the best-fit nonlinear equation that represents the data to
within 2% of each test point to determine concentration. If you use a
gas divider to blend calibration gases, verify that the calibration
curve produced names a calibration gas within 2% of its certified
concentration. Perform this verification between 15 and 50% of the full
scale analyzer range.
    (2) Use the linearity requirements of 40 CFR 1065.307, except for
CO2 measurements used for determining fuel economy and GHG
emissions for motor vehicles at or below 14,000 pounds GVWR. If you
choose this linearity option, you must drift check and drift correct
your emission data according to 40 CFR 1065.672.
    (c) Perform linearity verifications for the following temperature
measurements instead of those specified at 40 CFR 1065.307(e)(7):
    (1) Test cell ambient air.
    (2) Dilution air for PM sampling, including CVS, double-dilution,
and partial-flow systems.
    (3) PM sample.
    (4) Chiller sample, for gaseous sampling systems that use thermal
chillers to dry samples and that use chiller temperature to calculate
dewpoint at the chiller outlet. For testing, if you choose to use the
high alarm temperature setpoint for the chiller temperature as a
constant value in determining the amount of water removed from the
emission sample, you may verify the accuracy of the high alarm
temperature setpoint using good engineering judgment without following
the linearity verification for chiller temperature. We recommend that
you input a simulated reference temperature signal below the alarm
setpoint, increase this signal until the high alarm trips, and verify
that the alarm setpoint value is no less than 2 [deg]C below the
reference value at the trip point.
    (5) CVS inlet temperature.
    (d) Perform linearity verifications for the following pressure
measurements instead of those specified at 40 CFR 1065.307(e)(8):
    (1) Exhaust back pressure.
    (2) Barometric pressure.
    (3) CVS inlet gage pressure or absolute pressure transducer.
    (4) Sample dryer, for gaseous sampling systems that use either
osmotic-membrane or thermal chillers to dry samples. For your testing,
if you choose to use a low alarm pressure setpoint for the sample dryer
pressure as a constant value in determining the amount of water removed
from the emission sample, you may verify the accuracy of the low alarm
pressure setpoint using good engineering judgment without following the
linearity verification for sample dryer pressure. We recommend that you
input a reference pressure signal above the alarm setpoint, decrease
this signal until the low alarm trips, and verify that the alarm
setpoint value is no more than 4 kPa above the reference value at the
trip point.
    (e) When following procedures or practices that we incorporate by
reference in Sec.  1066.1010, you must meet the linearity requirements
given by the procedure or practice for any analytical instruments not
covered under 40 CFR 1065.307, such as GC-FID or HPLC.

Sec.  1066.140  Diluted exhaust flow calibration.

    (a) Overview. This section describes how to calibrate flow meters
for diluted exhaust constant-volume sampling (CVS) systems. You may
follow the molar flow calibration procedures in 40 CFR 1065.340 instead
of the procedures in this section.
    (b) Scope and frequency. Perform this calibration while the flow
meter is installed in its permanent position, except as allowed in
paragraph (c) of this section. Perform this calibration after you
change any part of the flow

configuration upstream or downstream of the flow meter that may affect
the flow-meter calibration. Perform this calibration upon initial CVS
installation and whenever corrective action does not resolve a failure
to meet the diluted exhaust flow verification (i.e., propane check) in
40 CFR 1065.341.
    (c) Ex-situ CFV and SSV calibration. You may remove a CFV or SSV
from its permanent position for calibration as long as the flow meter
meets the requirements in 40 CFR 1065.340(c).
    (d) Reference flow meter. Calibrate each CVS flow meter using a
reference flow meter such as a subsonic venturi flow meter, a long-
radius ASME/NIST flow nozzle, a smooth approach orifice, a laminar flow
element, a set of critical flow venturis, or an ultrasonic flow meter.
Use a reference flow meter that reports quantities that are NIST-
traceable within 1[percnt] uncertainty. Use this reference
flow meter's response to flow as the reference value for CVS flow-meter
calibration.
    (e) Configuration. Calibrate the system with any upstream screens
or other restrictions that will be used during testing and that could
affect the flow ahead of the reference flow meter. You may not use any
upstream screen or other restriction that could affect the flow ahead
of the reference flow meter, unless the flow meter has been calibrated
with such a restriction.
    (f) PDP calibration. Calibrate each positive-displacement pump
(PDP) to determine a flow-versus-PDP speed equation that accounts for
flow leakage across sealing surfaces in the PDP as a function of PDP
inlet pressure. Determine unique equation coefficients for each speed
at which you operate the PDP. Calibrate a PDP flow meter as follows:
    (1) Connect the system as shown in Figure 1 of this section.
    (2) Leaks between the calibration flow meter and the PDP must be
less than 0.3[percnt] of the total flow at the lowest calibrated flow
point; for example, at the highest restriction and lowest PDP-speed
point.
    (3) While the PDP operates, maintain a constant temperature at the
PDP inlet within 2[percnt] of the mean absolute inlet
temperature, Tin.
    (4) Set the PDP speed to the first speed point at which you intend
to calibrate.
    (5) Set the variable restrictor to its wide-open position.
    (6) Operate the PDP for at least 3 min to stabilize the system.
Continue operating the PDP and record the mean values of at least 30
seconds of sampled data of each of the following quantities:
    (i) The mean flow rate of the reference flow meter,
Qref. This may include several measurements of different
quantities, such as reference meter pressures and temperatures, for
calculating Qref.
    (ii) The mean temperature at the PDP inlet, Tin.
    (iii) The mean static absolute pressure at the PDP inlet,
pin.
    (iv) The mean static absolute pressure at the PDP outlet,
pout.
    (v) The mean PDP speed, fnPDP.
    (7) Incrementally close the restrictor valve to decrease the
absolute pressure at the inlet to the PDP, pin.
    (8) Repeat the steps in paragraphs (e)(6) and (7) of this section
to record data at a minimum of six restrictor positions ranging from
the wide-open restrictor position to the minimum expected pressure at
the PDP inlet.
    (9) Calibrate the PDP by using the collected data and the equations
in Sec.  1066.650(a).
    (10) Repeat the steps in paragraphs (e)(6) through (9) of this
section for each speed at which you operate the PDP.
    (11) Use the equations in Sec.  1066.652(a) to determine the PDP
flow equation for emission testing.
    (12) Verify the calibration by performing a CVS verification (i.e.,
propane check) as described in 40 CFR 1065.341.
    (13) Ensure that the lowest inlet pressure tested during
calibration is at least as low as the lowest PDP inlet pressure that
will occur during emission testing. You may not use the PDP below the
lowest inlet pressure tested during calibration.
    (g) SSV calibration. Calibrate each subsonic venturi (SSV) to
determine its discharge coefficient, Cd, for the expected
range of inlet pressures as follows:
    (1) Configure your calibration system as shown in Figure 1 of this
section.
    (2) Verify that any leaks between the calibration flow meter and
the SSV are less than 0.3[percnt] of the total flow at the highest
restriction.
    (3) Start the blower downstream of the SSV.
    (4) While the SSV operates, maintain a constant temperature at the
SSV inlet within 2[percnt] of the mean absolute inlet
temperature, Tin.
    (5) Set the variable restrictor or variable-speed blower to a flow
rate greater than the greatest flow rate expected during testing. You
may not extrapolate flow rates beyond calibrated values, so we
recommend that you make sure the Reynolds number,
Re, at the SSV throat at the greatest calibrated
flow rate is greater than the maximum Re expected
during testing.
    (6) Operate the SSV for at least 3 min to stabilize the system.
Continue operating the SSV and record the mean of at least 30 seconds
of sampled data of each of the following quantities:
    (i) The mean flow rate of the reference flow meter,
Qref. This may include several measurements of different
quantities for calculating Qref, such as reference meter
pressures and temperatures.
    (ii) The mean temperature at the venturi inlet, Tin.
    (iii) The mean static absolute pressure at the venturi inlet,
Pin.
    (iv) Mean static differential pressure between the static pressure
at the venturi inlet and the static pressure at the venturi throat,
[Dgr]Pssv.
    (7) Incrementally close the restrictor valve or decrease the blower
speed to decrease the flow rate.
    (8) Repeat the steps in paragraphs (g)(6) and (7) of this section
to record data at a minimum of ten flow rates.
    (9) Determine an equation to quantify Cd as a function
of Re by using the collected data and the equations
in Sec.  1066.650(b). Section 1066.650 also includes statistical
criteria for validating the Cd versus Re
equation.
    (10) Verify the calibration by performing a CVS verification (i.e.,
propane check) as described in 40 CFR 1065.341 using the Cd
versus Re equation.
    (11) Use the SSV only between the minimum and maximum calibrated
flow rates. If you want to use the SSV at a higher or lower flow rate,
you must recalibrate the SSV.
    (12) Use the equations in Sec.  1066.652(b) to determine SSV flow
during a test.
    (h) CFV calibration. The calibration procedure described in this
paragraph (h) establishes the value of the calibration coefficient at
measured values of pressure, temperature and air flow.
    Calibrate a critical-flow venturi (CFV) to verify its calibration
coefficient, Kv, at the lowest expected static differential
pressure between the CFV inlet and outlet. Calibrate a CFV flow meter
as follows:
    (1) Configure your calibration system as shown in Figure 1 of this
section.
    (2) Verify that any leaks between the calibration flow meter and
the CFV are less than 0.3[percnt] of the total flow at the highest
restriction.
    (3) Start the blower downstream of the CFV.
    (4) While the CFV operates, maintain a constant temperature at the
CFV inlet within 2[percnt] of the mean absolute inlet
temperature, Tin.
    (5) Set the variable restrictor to its wide-open position. Instead
of a

variable restrictor, you may alternately vary the pressure downstream
of the CFV by varying blower speed or by introducing a controlled leak.
Note that some blowers have limitations on nonloaded conditions.
    (6) Operate the CFV for at least 3 min to stabilize the system.
Continue operating the CFV and record the mean values of at least 30
seconds of sampled data of each of the following quantities:
    (i) The mean flow rate of the reference flow meter,
Qref. This may include several measurements of different
quantities, such as reference meter pressures and temperatures, for
calculating Qref.
    (ii) The mean temperature at the venturi inlet, Tin.
    (iii) The mean static absolute pressure at the venturi inlet,
pin.
    (iv) The mean static differential pressure between the CFV inlet
and the CFV outlet, [Dgr]p CFV.
    (7) Incrementally close the restrictor valve or decrease the
downstream pressure to decrease the differential pressure across the
CFV, [Dgr]p CFV.
    (8) Repeat the steps in paragraphs (f)(6) and (7) of this section
to record mean data at a minimum of ten restrictor positions, such that
you test the fullest practical range of [Dgr]p CFV expected
during testing. We do not require that you remove calibration
components or CVS components to calibrate at the lowest possible
restriction.
    (9) Determine K v and the lowest allowable pressure
ratio, r, according to Sec.  1066.650.
    (10) Use K v to determine CFV flow during an emission
test. Do not use the CFV below the lowest allowed r, as determined in
Sec.  1066.650.
    (11) Verify the calibration by performing a CVS verification (i.e.,
propane check) as described in 40 CFR 1065.341.
    (12) If your CVS is configured to operate multiple CFVs in
parallel, calibrate your CVS using one of the following methods:
    (i) Calibrate every combination of CFVs according to this section
and Sec.  1066.650(c). Refer to Sec.  1065.652(c) for instructions on
calculating flow rates for this option.
    (ii) Calibrate each CFV according to this section and Sec.
1066.650. Refer to Sec.  1066.652 for instructions on calculating flow
rates for this option.
    (i) Ultrasonic flow meter calibration. [Reserved]
BILLING CODE P

[GRAPHIC] [TIFF OMITTED] TP21MY13.043

Sec.  1066.145  Test fuel, engine fluids, analytical gases, and other
calibration standards.

    (a) Test fuel. Use test fuel as specified in the standard-setting
part, or as specified in 40 CFR part 1065, subpart H, if it is not
specified in the standard-setting part.
    (b) Lubricating oil. Use lubricating oil as specified in 40 CFR
1065.740. For two-stroke engines that involve a specified mixture of
fuel and lubricating oil, mix the lubricating oil with the fuel
according to the manufacturer's specifications.
    (c) Coolant. For liquid-cooled engines, use coolant as specified in
40 CFR 1065.745.
    (d) Analytical gases. Use analytical gases that meet the
requirements of 40 CFR 1065.750.
    (e) Mass standards. Use mass standards that meet the requirements
of 40 CFR 1065.790.

Sec.  1066.150  Analyzer interference and quench verification limit.

    Analyzers must meet the interference and quench verification limits
in the following table on the lowest instrument range that will be used
during emission testing, instead of those specified in 40 CFR part
1065, subpart D:

Table 1 of Sec.   1066.150-Analyzer Interference and Quench Verification
                                 Limits
------------------------------------------------------------------------
             Verification                             Limit
------------------------------------------------------------------------
40 CFR 1065.350.......................  2% of full scale.
40 CFR 1065.355.......................  2% of full scale.
40 CFR 1065.370.......................  2% of full scale.
40 CFR 1065.375.......................  2% of the flow-
                                         weighted mean concentration of
                                         N2O expected at the standard.
------------------------------------------------------------------------

Subpart C--Dynamometer Specifications

Sec.  1066.201  Dynamometer overview.

    This subpart addresses chassis dynamometers and related equipment.

Sec.  1066.210  Dynamometers.

    (a) General requirements. A chassis dynamometer typically uses
electrically generated load forces combined with its rotational inertia
to recreate the mechanical inertia and frictional forces that a vehicle
exerts on road surfaces (known as ``road load''). Load forces are
calculated using vehicle-specific coefficients and response
characteristics. The load forces are applied to the vehicle tires by
rolls connected to motor/absorbers. The dynamometer uses a load cell to
measure the forces the dynamometer rolls apply to the vehicle's tires.
    (b) Accuracy and precision. The dynamometer's output values for
road load must be NIST-traceable. We may determine traceability to a
specific international standards organization to be sufficient to
demonstrate NIST-traceability. The force-measurement system must be
capable of indicating force readings as follows:
    (1) For dynamometer testing of vehicles at or below 20,000 pounds
GVWR, the dynamometer force-measurement system must be capable of
indicating force readings during a test to a resolution of 0.05% of the maximum load-cell force simulated by the dynamometer
or 9.8 N (2.2 lbf), whichever is greater.
    (2) For dynamometers testing of vehicles above 20,000 pounds GVWR
the force-measurement system must be capable of indicating force
readings during a test to a resolution of 0.05% of the
maximum load-cell force simulated by the dynamometer or 39.2 N (8.8 lbf), whichever is greater.
    (c) Test cycles. The dynamometer must be capable of fully
simulating vehicle performance over applicable test cycles for the
vehicles being tested as referenced in the corresponding standard-
setting part, including operation at the combination of inertial and
road-load forces corresponding to maximum road load conditions and
maximum simulated inertia at the highest acceleration rate experienced
during testing.
    (d) Component requirements. The following specifications apply:
    (1) The nominal roll diameter must be 120 cm or greater. The
dynamometer must have an independent drive roll for each drive axle as
tested under Sec.  1066.410(g), except that two drive axles may share a
single drive roll. Use good engineering judgment to ensure that the
dynamometer roll diameter is large enough to provide sufficient tire-
roll contact area to avoid tire overheating and power losses from tire-
roll slippage.
    (2) Measure and record force and speed at 10 Hz or faster. You may
convert measured values to 1-Hz, 2-Hz, or 5-Hz values before your
calculations, using good engineering judgment.
    (3) The load applied by the dynamometer simulates forces acting on
the vehicle during normal driving according to the following equation:
[GRAPHIC] [TIFF OMITTED] TP21MY13.044

Where:

FR = total road-load force to be applied at the surface of the roll.
The total force is the sum of the individual tractive forces applied
at each roll surface.
i = a counter to indicate a point in time over the driving schedule.
For a dynamometer operating at 10-Hz intervals over a 600-second
driving schedule, the maximum value of i should be 6,000.
A = a vehicle-specific constant value representing the vehicle's
frictional load in lbf or newtons. See subpart D of this part.
B = a vehicle-specific coefficient representing load from drag and
rolling resistance, which are a function of vehicle speed, in lbf/
mph or N[middot]s/m. See subpart D of this part.
v = linear speed at the roll surfaces as measured by the
dynamometer, in mph or m/s. Let vi-1 = 0 for i = 0.
C = a vehicle-specific coefficient representing aerodynamic effects,
which are a function of vehicle speed squared, in lbf/mph\2\ or
N[middot]s\2\/m\2\. See subpart D of this part.
M = mass of the vehicle in lbm or kg. For vehicles at or below
14,000 pounds GVWR, determine the vehicle's mass based on equivalent
test weight (ETW) as specified in Sec.  1066.810 and set dynamometer
inertia simulation as specified in Sec.  1066.410(h). For vehicles
above 14,000 pounds GVWR, determine the vehicle's mass based on the
test weight, taking into account the effect of rotating axles, as
specified in Sec.  1066.310(b)(7) and dividing the weight by the
acceleration due to gravity as specified in 40 CFR 1065.630,
consistent with good engineering judgment.
t = elapsed time in the driving schedule as measured by the
dynamometer, in seconds. Let ti-1 = 0 for i = 0.

    (4) We recommend that a dynamometer capable of testing vehicles at
or below 20,000 pounds GVWR be designed to apply an actual road-load
force within 1% or 9.8 N (2.2 lbf)
of the reference value, whichever is greater. Dynamometers that do not
fully meet this specification may be used consistent with good
engineering judgment. For example, slightly higher errors may be
permissible during highly transient operation for vehicles above 8,500
pounds GVWR.
    (e) Dynamometer manufacturer instructions. This part specifies that
you follow the dynamometer manufacturer's recommended procedures for
things such as calibrations and general operation. If you perform
testing with a dynamometer that you manufactured or if you otherwise do
not have these recommended procedures, use good engineering judgment to
establish the additional procedures and specifications we specify in
this part, unless we specify otherwise. Keep records to describe these
recommended procedures and how they are consistent

with good engineering judgment, including any quantified error
estimates.

Sec.  1066.215  Summary of verification and calibration procedures for
chassis dynamometers.

    (a) Overview. This section describes the overall process for
verifying and calibrating the performance of chassis dynamometers.
    (b) Scope and frequency. The following table summarizes the
required and recommended calibrations and verifications described in
this subpart and indicates when they must occur:

Table 1 of Sec.   1066.215--Summary of Required Dynamometer Calibrations
                            and Verifications
------------------------------------------------------------------------
    Type of calibration or
         verification                    Minimum frequency \a\
------------------------------------------------------------------------
Sec.   1066.220: Linearity     Speed: Upon initial installation, within
 verification.                  370 days before testing, and after major
                                maintenance.
                               Torque (load): Upon initial installation
                                and after major maintenance.
Sec.   1066.225: Roll runout   Upon initial installation and after major
 and diameter verification.     maintenance.
Sec.   1066.230: Time          Upon initial installation and after major
 verification.                  maintenance.
Sec.   1066.235: Speed         Upon initial installation, within 370
 measurement verification.      days before testing, and after major
                                maintenance.
Sec.   1066.240: Torque        Upon initial installation, within 7 days
 (load) transducer              of testing, and after major maintenance.
 verification.
Sec.   1066.245: Response      Upon initial installation, within 370
 time verification.             days before testing, and after major
                                maintenance.
Sec.   1066.250: Base inertia  Upon initial installation and after major
 verification.                  maintenance.
Sec.   1066.255: Parasitic     Upon initial installation, after major
 loss verification.             maintenance, and upon failure of a
                                verification in Sec.   1066.270 or Sec.
                                 1066.280.
Sec.   1066.260: Parasitic     Upon initial installation, after major
 friction compensation          maintenance, and upon failure of a
 evaluation.                    verification in Sec.   1066.270 or Sec.
                                 1066.280.
Sec.   1066.265: Acceleration  Upon initial installation and after major
 and deceleration               maintenance.
 verification.
Sec.   1066.270: Unloaded      Upon initial installation, within 7 days
 coastdown verification.        of testing, and after major maintenance.
Sec.   1066.280 Dynamometer    Upon initial installation, within 1 day
 readiness verification.        before testing, and after major
                                maintenance.
------------------------------------------------------------------------
\a\ Perform calibrations and verifications more frequently, according to
  measurement system manufacturer instructions and good engineering
  judgment.

     (c) Automated dynamometer verifications and calibrations. In some
cases, dynamometers are designed with internal diagnostic and control
features to accomplish the verifications and calibrations specified in
this subpart. You may use these automated functions instead of
following the procedures we specify in this subpart to demonstrate
compliance with applicable requirements, consistent with good
engineering judgment.
    (d) Sequence of verifications and calibrations. Upon initial
installation and after major maintenance, perform the verifications and
calibrations in the same sequence as noted in Table 1 of this section,
except that you may perform speed linearity verification after the
verifications in Sec. Sec.  1066.225 and 1066.230. At other times, you
may need to perform specific verifications or calibrations in a certain
sequence, as noted in this subpart. If you perform major maintenance on
a specific component, you are required to perform verifications and
calibrations only on components or parameters that are affected by the
maintenance.
    (e) Corrections. Unless the regulation directs otherwise, if the
dynamometer fails to meet any specified calibration or verification,
make any necessary adjustments or repairs such that the dynamometer
meets the specification before running a test. Repairs required to meet
specifications are generally considered major maintenance under this
part.

Sec.  1066.220  Linearity verification for chassis dynamometer systems.

    (a) Scope and frequency. Perform linearity verification for
dynamometer speed and torque at least as frequently as indicated in
Table 1 of Sec.  1066.215. The intent of linearity verification is to
determine that the system responds accurately and proportionally over
the measurement range of interest. Linearity verification generally
consists of introducing a series of at least 10 reference values to a
measurement system. The measurement system quantifies each reference
value. The measured values are then collectively compared to the
reference values by using a least-squares linear regression and the
linearity criteria specified in Table 1 of this section.
    (b) Performance requirements. If a measurement system does not meet
the applicable linearity criteria in Table 1 of this section, correct
the deficiency by re-calibrating, servicing, or replacing components as
needed. Repeat the linearity verification after correcting the
deficiency to ensure that the measurement system meets the linearity
criteria. Before you may use a measurement system that does not meet
linearity criteria, you must demonstrate to us that the deficiency does
not adversely affect your ability to demonstrate compliance with the
applicable standards.
    (c) Procedure. Use the following linearity verification protocol,
or use good engineering judgment to develop a different protocol that
satisfies the intent of this section, as described in paragraph (a) of
this section:
    (1) In this paragraph (c), the letter ``y'' denotes a generic
measured quantity, the superscript over-bar denotes an arithmetic mean
(such as y), and the subscript ``ref'' denotes the known or
reference quantity being measured.
    (2) Operate the dynamometer system at the specified operating
conditions. This may include any specified adjustment or periodic
calibration of the dynamometer system.
    (3) Set dynamometer speed and torque to zero.
    (4) Verify the dynamometer speed or torque signal based on the
dynamometer manufacturer's recommendations.
    (5) After verification, check for zero speed and torque. Use good
engineering judgment to determine whether or not to rezero or re-verify
speed and torque before continuing.
    (6) For both speed and torque, use the dynamometer manufacturer's
recommendations and good engineering judgment to select reference
values, yrefi, that cover a range of values that you expect
would prevent extrapolation beyond these values during emission
testing. We recommend selecting zero

speed and zero torque as reference values for the linearity
verification.
    (7) Use the dynamometer manufacturer's recommendations and good
engineering judgment to select the order in which you will introduce
the series of reference values. For example, you may select the
reference values randomly to avoid correlation with previous
measurements and to avoid the influence of hysteresis; you may select
reference values in ascending or descending order to avoid long
settling times of reference signals; or you may select values to ascend
and then descend to incorporate the effects of any instrument
hysteresis into the linearity verification.
    (8) Set the dynamometer to operate at a reference condition.
    (9) Allow time for the dynamometer to stabilize while it measures
the reference values.
    (10) At a recording frequency of at least 1 Hz, measure speed and
torque values for 30 seconds and record the arithmetic mean of the
recorded values, yi. Refer to 40 CFR 1065.602 for an example
of calculating an arithmetic mean.
    (11) Repeat the steps in paragraphs (c)(8) though (10) of this
section until you measure speeds and torques at each of the reference
settings.
    (12) Use the arithmetic means, yi, and reference values,
yrefi, to calculate least-squares linear regression
parameters and statistical values to compare to the minimum performance
criteria specified in Table 1 of this section. Use the calculations
described in 40 CFR 1065.602. Using good engineering judgment, you may
weight the results of individual data pairs (i.e., (yrefi,
y), in the linear regression calculations. Table 1 follows:

        Table 1 of Sec.   1066.220--Dynamometer Measurement Systems That Require Linearity Verifications
----------------------------------------------------------------------------------------------------------------
                                                                      Linearity criteria
                                            --------------------------------------------------------------------
     Measurement system          Quantity    [verbarlm]ymin(a1-
                                              1)+a0 [verbarlm]         a1              SEE             r\2\
----------------------------------------------------------------------------------------------------------------
Speed.......................  v              <0.05%                   0.98-1.02  <2%                      >0.990
                                              [middot]v\max\.                     [middot]v\max\.
Torque (load)...............  T              <1% [middot]T\max\       0.99-1.01  <1%                      >0.990
                                                                                [middot]T\max\.
----------------------------------------------------------------------------------------------------------------

     (d) Reference signals. Generate reference values for the
linearity-verification protocol in paragraph (c) of this section as
described for speed and torque in 40 CFR 1065.307(d).

Sec.  1066.225  Roll runout and diameter verification procedure.

    (a) Overview. This section describes the verification procedure for
roll runout and roll diameter. Roll runout is a measure of the
variation in roll radius around the circumference of the roll.
    (b) Scope and frequency. Perform these verifications upon initial
installation and after major maintenance that could affect roll surface
finish or dimensions (such as resurfacing or polishing).
    (c) Roll runout procedure. Verify roll runout based on the
following procedure, or an equivalent procedure based on good
engineering judgment:
    (1) Perform this verification with laboratory and dynamometer
temperatures stable and at equilibrium. Release the roll brake and shut
off power to the dynamometer. Remove any dirt, rubber, rust, and debris
from the roll surface. Mark measurement locations on the roll surface
using a nominally permanent marker. Mark the roll at a minimum of four
equally spaced locations across the roll width; we recommend taking
measurements every 150 mm across the roll. Secure the marker to the
deck plate adjacent to the roll surface and slowly rotate the roll to
mark a clear line around the roll circumference. Repeat this process
for all measurement locations.