Title 40
SECTION 1065.1005
1065.1005 Symbols, abbreviations, acronyms, and units of measure.
§ 1065.1005 Symbols, abbreviations, acronyms, and units of measure.The procedures in this part generally follow the International System of Units (SI), as detailed in NIST Special Publication 811, which we incorporate by reference in § 1065.1010. See § 1065.20 for specific provisions related to these conventions. This section summarizes the way we use symbols, units of measure, and other abbreviations.
(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 |
---|---|---|---|---|
a | 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 | |||
ag | acceleration of Earth's gravity | meter per square second | m/s ^{2} | m·s−2. |
b | ratio of diameters | meter per meter | m/m | 1. |
b | atomic oxygen-to-carbon ratio | mole per mole | mol/mol | 1. |
C# | number of carbon atoms in a molecule | |||
Cd | discharge coefficient | |||
Cf | flow coefficient | |||
d | atomic nitrogen-to-carbon ratio | mole per mole | mol/mol | 1. |
d | Diameter | meter | m | m. |
DR | dilution ratio | mole per mole | mol/mol | 1. |
e | error between a quantity and its reference | |||
e | brake-specific emission or fuel consumption | gram per kilowatt hour | g/(kW·hr) | g·3.6·10−6·;m−2·kg−1·s ^{2}. |
F | F-test statistic | |||
f | frequency | hertz | Hz | s−1. |
fn | angular speed (shaft) | revolutions per minute | r/min | π·30−1·s−1. |
g | ratio of specific heats | (joule per kilogram kelvin) per (joule per kilogram kelvin) | (J/(kg·K))/(J/(kg·K)) | 1. |
g | atomic sulfur-to-carbon ratio | mole per mole | mol/mol | 1. |
K | correction factor | 1. | ||
Kv | calibration coefficient | m ^{4}·;s·K ^{0.5}/kg | m ^{4}·kg−1s·K ^{0.5}. | |
l | length | meter | m | m. |
m | viscosity, dynamic | pascal second | Pa·s | m−1·kg·s−1. |
M | molar mass ^{1} | gram per mole | g/mol | 10−3·kg·mol−1. |
m | mass | kilogram | kg | kg. |
m | mass rate | kilogram per second | kg/s | kg·s−1. |
n | viscosity, kinematic | meter squared per second | m ^{2}/s | m ^{2}·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·s−1. |
P | power | kilowatt | kW | 10 ^{3}·m ^{2}·kg·s−3. |
PF | penetration fraction | |||
p | pressure | pascal | Pa | m−1·kg·s−2. |
r | mass density | kilogram per cubic meter | kg/m ^{3} | m−3·kg. |
D | differential static pressure | pascal | Pa | m−1·kg·s−2. |
r | ratio of pressures | pascal per pascal | Pa/Pa | 1. |
r ^{2} | coefficient of determination | |||
Ra | average surface roughness | micrometer | µm | 10−6·m. |
Re# | Reynolds number | |||
RF | response factor | |||
RH | relative humidity | |||
s | 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 | °C | K - 273.15. |
T | torque (moment of force) | newton meter | N·m | m ^{2}·kg·s−2. |
θ | plane angle | degrees | ° | rad. |
t | time | second | s | s. |
Δt | 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}·s−1. |
W | work | kilowatt-hour | kW·hr | 3.6−1·10 ^{6}·m ^{2}·kg·s−2. |
wC | carbon mass fraction | gram per gram | g/g | 1. |
x | amount of substance mole fraction ^{2} | mole per mole | mol/mol | 1. |
x | flow-weighted mean concentration | mole per mole | mol/mol | 1. |
y | generic variable | |||
Z | compressibility factor |
^{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.
(b) Symbols for chemical species. This part uses the following symbols for chemical species and exhaust constituents:
Symbol | Species |
---|---|
Ar | argon. |
C | carbon. |
CH2O | formaldehyde. |
CH2O2 | formic acid. |
CH3OH | methanol. |
CH4 | methane. |
C2H4O | acetaldehyde. |
C2H5OH | ethanol. |
C2H6 | ethane. |
C3H7OH | propanol. |
C3H8 | propane. |
C4H10 | butane. |
C5H12 | pentane. |
CO | carbon monoxide. |
CO2 | carbon dioxide. |
H | atomic hydrogen. |
H2 | molecular hydrogen. |
H2O | water. |
H2SO4 | sulfuric acid. |
HC | hydrocarbon. |
He | helium. |
^{85}Kr | krypton 85. |
N2 | molecular nitrogen. |
NH3 | ammonia. |
NMHC | nonmethane hydrocarbon. |
NMHCE | nonmethane hydrocarbon equivalent. |
NMNEHC | nonmethane-nonethane hydrocarbon. |
NO | nitric oxide. |
NO2 | nitrogen dioxide. |
NOX | oxides of nitrogen. |
N2O | nitrous oxide. |
NMOG | nonmethane organic gases. |
NONMHC | non-oxygenated nonmethane hydrocarbon. |
NOTHC | non-oxygenated total hydrocarbon. |
O2 | molecular oxygen. |
OHC | oxygenated hydrocarbon. |
^{210}Po | polonium 210. |
PM | particulate matter. |
S | sulfur. |
SVOC | semi-volatile organic compound. |
THC | total hydrocarbon. |
THCE | total hydrocarbon equivalent. |
ZrO2 | zirconium dioxide. |
(c) Prefixes. This part uses the following prefixes to define a quantity:
Symbol | Quantity | Value |
---|---|---|
µ | micro | 10−6 |
m | milli | 10−3 |
c | centi | 10−2 |
k | kilo | 10 ^{3} |
M | mega | 10 ^{6} |
(d) Superscripts. This part uses the following superscripts to define a quantity:
Superscript | Quantity |
---|---|
overbar (such as y ) | arithmetic mean. |
overdot (such as y ) | quantity per unit time. |
(e) Subscripts. This part uses the following subscripts to define a quantity:
Subscript | Quantity |
---|---|
abs | absolute quantity. |
act | actual condition. |
air | air, dry. |
amb | ambient. |
atmos | atmospheric. |
bkgnd | background. |
cal | calibration quantity. |
CFV | critical flow venturi. |
comb | combined. |
composite | composite value. |
cor | corrected quantity. |
dil | dilution air. |
dew | dewpoint. |
dexh | diluted exhaust. |
dry | dry condition. |
dutycycle | duty cycle. |
exh | raw exhaust. |
exp | expected quantity. |
fn | feedback speed. |
frict | friction. |
fuel | fuel consumption. |
hi, idle | condition at high-idle. |
i | an individual of a series. |
idle | condition at idle. |
in | quantity in. |
init | initial quantity, typically before an emission test. |
int | intake air. |
j | an individual of a series. |
mapped | conditions over which an engine can operate. |
max | the maximum (i.e., peak) value expected at the standard over a test interval; not the maximum of an instrument range. |
meas | measured quantity. |
media | PM sample media. |
mix | mixture of diluted exhaust and air. |
norm | normalized. |
out | quantity out. |
P | power. |
part | partial quantity. |
PDP | positive-displacement pump. |
post | after the test interval. |
pre | before the test interval. |
prod | stoichiometric product. |
record | record rate. |
ref | reference quantity. |
rev | revolution. |
sat | saturated condition. |
s | slip. |
span | span quantity. |
SSV | subsonic venturi. |
std | standard condition. |
stroke | engine strokes per power stroke. |
T | torque. |
test | test quantity. |
test, alt | alternate test quantity. |
uncor | uncorrected quantity. |
vac | vacuum side of the sampling system. |
weight | calibration weight. |
zero | zero quantity. |
(f) Constants. (1) This part uses the following constants for the composition of dry air:
Symbol | Quantity | mol/mol |
---|---|---|
xArair | amount of argon in dry air | 0.00934 |
xCO2air | amount of carbon dioxide in dry air | 0.000375 |
xN2air | amount of nitrogen in dry air | 0.78084 |
xO2air | amount of oxygen in dry air | 0.209445 |
(2) This part uses the following molar masses or effective molar masses of chemical species:
Symbol | Quantity | g/mol (10−3·kg·mol−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 |
MCH4N2O | molar mass of urea | 60.05526 |
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 |
MCH2O | 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 ^{2} | 13.875389 |
MNMHCE | effective C1 molar mass of nonmethane hydrocarbon equivalent ^{2} | 13.875389 |
MNMNEHC | effective C1 molar mass of nonmethane-nonethane hydrocarbon ^{2} | 13.875389 |
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 equivalent ^{2} | 13.875389 |
^{1} See paragraph (f)(1) of this section for the composition of dry air.
^{2} The effective molar masses of THC, THCE, NMHC, NMHCE, and NMNEHC are defined on a C1 basis and are based on an atomic hydrogen-to-carbon ratio, a, of 1.85 (with b, g, and d equal to zero).
^{3} The effective molar mass of NOX is defined by the molar mass of nitrogen dioxide, NO2.
(3) This part uses the following molar gas constant for ideal gases:
Symbol | Quantity | J/(mol · K) (m ^{2} · kg · s−2 · mol−1 · K−1) |
---|---|---|
R | molar gas constant | 8.314472 |
(4) This part uses the following ratios of specific heats for dilution air and diluted exhaust:
Symbol | Quantity | [J/(kg · K)]/[J/(kg · K)] |
---|---|---|
gair | ratio of specific heats for intake air or dilution air | 1.399 |
gdil | ratio of specific heats for diluted exhaust | 1.399 |
gexh | ratio of specific heats for raw exhaust | 1.385 |
(g) Other acronyms and abbreviations. This part uses the following additional abbreviations and acronyms:
ABS | acrylonitrile-butadiene-styrene. |
ASTM | American Society for Testing and Materials. |
BMD | bag mini-diluter. |
BSFC | brake-specific fuel consumption. |
CARB | California Air Resources Board. |
CFR | Code of Federal Regulations. |
CFV | critical-flow venturi. |
CI | compression-ignition. |
CITT | Curb Idle Transmission Torque. |
CLD | chemiluminescent detector. |
CVS | constant-volume sampler. |
DF | deterioration factor. |
ECM | electronic control module. |
EFC | electronic flow control. |
e.g | for example. |
EGR | exhaust gas recirculation. |
EPA | Environmental Protection Agency. |
FEL | Family Emission Limit. |
FID | flame-ionization detector. |
FTIR | Fourier transform infrared. |
GC | gas chromatograph. |
GC-ECD | gas chromatograph with an electron-capture detector. |
GC-FID | gas chromatograph with a flame ionization detector. |
HEPA | high-efficiency particulate air. |
IBP | initial boiling point. |
IBR | incorporated by reference. |
i.e | in other words. |
ISO | International Organization for Standardization. |
LPG | liquefied petroleum gas. |
MPD | magnetopneumatic detection. |
NDIR | nondispersive infrared. |
NDUV | nondispersive ultraviolet. |
NIST | National Institute for Standards and Technology. |
NMC | nonmethane cutter. |
PDP | positive-displacement pump. |
PEMS | portable emission measurement system. |
PFD | partial-flow dilution. |
PLOT | porous layer open tubular. |
PMD | paramagnetic detection. |
PMP | Polymethylpentene. |
pt | a single point at the mean value expected at the standard. |
psi | pounds per square inch. |
PTFE | polytetrafluoroethylene (commonly known as Teflon ^{TM}). |
RE | rounding error. |
RESS | rechargeable energy storage system. |
RFPF | response factor penetration fraction. |
RMC | ramped-modal cycle. |
rms | root-mean square. |
RTD | resistive temperature detector. |
SAW | surface acoustic wave. |
SEE | standard estimate of error. |
SSV | subsonic venturi. |
SI | spark-ignition. |
THC-FID | total hydrocarbon flame ionization detector. |
TINV | inverse student t-test function in Microsoft Excel. |
UCL | upper confidence limit. |
UFM | ultrasonic flow meter. |
U.S.C | United States Code. |