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The abbreviations in this section apply to this subpart and also to subparts B, D, H, I, J, N, O and P of this part and have the following meanings:
accel. - acceleration.
AECD - Auxiliary emission control device.
API - American Petroleum Institute.
ASTM - American Society for Testing and Materials.
BHP - Brake horsepower.
BSCO - Brake specific carbon monoxide.
BSHC - Brake specific hydrocarbons.
BSNOX - Brake specific oxides of nitrogen.
C - Celsius.
cfh - cubic feet per hour.
CFV - Critical flow venturi.
CFV-CVS - Critical flow venturi - constant volume sampler.
CH4 methane.
CL - Chemiluminescence.
CO2 - carbon dioxide.
CO - Carbon monoxide.
conc. - concentration.
cfm - cubic feet per minute.
CT - Closed throttle.
cu. in. - cubic inch(es).
CVS - Constant volume sampler.
decel. - deceleration.
EP - End point.
evap. - evaporative.
F - Fahrenheit.
FID - Flame ionization detector.
FL - Full load.
ft. - feet.
g - gram(s).
gal. - U.S. gallon(s).
GVW - Gross vehicle weight.
GVWR - Gross vehicle weight rating.
h - hour(s).
H2O - water.
HC - hydrocarbon(s).
HFID - Heated flame ionization detector.
Hg - mercury.
hi - high.
hp. - horsepower.
IBP - Initial boiling point.
ID - Internal diameter.
in. - inch(es).
K - kelvin.
kg - kilogram(s).
km - kilometer(s).
kPa - kilopascal(s).
lb. - pound(s).
lb.-ft. - pound-feet.
m - meter(s).
max. - maximum.
mg - milligram(s).
mi. - mile(s).
min. - minute(s).
ml - milliliter(s).
mm - millimeter(s).
mph - miles per hour.
mv - millivolt(s).
N2 - nitrogen.
NDIR - Nondispersive infrared.
NO - nitric oxide.
NO2 - nitrogen dioxide.
N2O nitrous oxide.
NOX - oxides of nitrogen.
No. - Number.
O2 - oxygen.
Pb - lead.
pct. - percent.
PDP-CVS - Positive displacement pump - constant volume sampler.
ppm - parts per million by volume.
ppm C - parts per million, carbon.
psi - pounds per square inch.
psig - pounds per square inch gauge.
PTA - Part throttle acceleration.
PTD - Part throttle deceleration.
R - Rankin.
rpm - revolutions per minute.
RVP - Reid vapor pressure.
s - second(s).
SAE - Society of Automotive Engineers.
SI - International system of units.
sp. - speed.
TEL - Tetraethyl lead.
TML - Tetramethyl lead.
UDDS - Urban dynamometer driving schedule.
V - volt(s).
vs - versus.
W - watt(s).
WF - Weighting factor.
WOT - Wide open throttle.
wt. - weight.
′ - feet.
″ - inch(es).
° - degree(s).
∑ - summation.
[42 FR 32907, June 28, 1977, as amended at 45 FR 4149, Jan. 21, 1980; 74 FR 56373, Oct. 30, 2009]