Used in this part are abbreviations and symbols of units of measure. These are defined as follows:
(a) System International (SI) units of measure: A--ampereg--gramHz--hertzJ--joule K--degree Kelvinkg--kilogramm--meterm\3\--cubic metermg--milligram--10 -3 grammm--millimeter--10 -3 meterMg--megagram--10\6\ grammol--moleN--newtonng--nanogram--10 -9 gramnm--nanometer--10 -9 meterPa--pascals--secondV--voltW--watt[ohm]--ohm[micro]g--microgram--10 -6 gram
(b) Other units of measure: Btu--British thermal unit
[deg]C--degree Celsius (centigrade)cal--caloriecfm--cubic feet per minutecu ft--cubic feetdcf--dry cubic feetdcm--dry cubic meterdscf--dry cubic feet at standard conditionsdscm--dry cubic meter at standard conditionseq--equivalent[deg]F--degree Fahrenheitft--feetgal--gallongr--graing-eq--gram equivalenthr--hourin--inchk--1,000l--literlpm--liter per minutelb--poundmeq--milliequivalentmin--minuteml--millilitermol. wt.--molecular weightppb--parts per billionppm--parts per millionpsia--pounds per square inch absolutepsig--pounds per square inch gage[deg]R--degree Rankinescf--cubic feet at standard conditionsscfh--cubic feet per hour at standard conditionsscm--cubic meter at standard conditionssec--secondsq ft--square feetstd--at standard conditions
(c) Chemical nomenclature: CdS--cadmium sulfideCO--carbon monoxideCO2--carbon dioxideHCl--hydrochloric acidHg--mercuryH2O--waterH2S--hydrogen sulfideH2SO4--sulfuric acidN2--nitrogenNO--nitric oxideNO2--nitrogen dioxideNOX--nitrogen oxidesO2--oxygenSO2--sulfur dioxideSO3--sulfur trioxideSOX--sulfur oxides
(d) Miscellaneous: A.S.T.M.--American Society for Testing and Materials [42 FR 37000, July 19, 1977; 42 FR 38178, July 27, 1977]