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]