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.[foot]--feet.--inch(es).--degree(s).[sum]--summation. [42 FR 32907, June 28, 1977, as amended at 45 FR 4149, Jan. 21, 1980; 74 FR 56373, Oct. 30, 2009]