Title 40

SECTION 63.3

63.3 Units and abbreviations.

§ 63.3 Units and abbreviations.

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 = ampere g = gram Hz = hertz J = joule °K = degree Kelvin kg = kilogram l = liter m = meter m 3 = cubic meter mg = milligram = 10−3 gram ml = milliliter = 10−3 liter mm = millimeter = 10−3 meter Mg = megagram = 10 6 gram = metric ton MJ = megajoule mol = mole N = newton ng = nanogram = 10−9 gram nm = nanometer = 10−9 meter Pa = pascal s = second V = volt W = watt Ω = ohm µg = microgram = 10−6 gram µl = microliter = 10−6 liter

(b) Other units of measure:

Btu = British thermal unit °C = degree Celsius (centigrade) cal = calorie cfm = cubic feet per minute cc = cubic centimeter cu ft = cubic feet d = day dcf = dry cubic feet dcm = dry cubic meter dscf = dry cubic feet at standard conditions dscm = dry cubic meter at standard conditions eq = equivalent °F degree Fahrenheit ft = feet ft 2 = square feet ft 3 = cubic feet gal = gallon gr = grain g-eq = gram equivalent g-mole = gram mole hr = hour in. = inch in. H2 O = inches of water K = 1,000 kcal = kilocalorie lb = pound lpm = liter per minute meq = milliequivalent min = minute MW = molecular weight oz = ounces ppb = parts per billion ppbw = parts per billion by weight ppbv = parts per billion by volume ppm = parts per million ppmw = parts per million by weight ppmv = parts per million by volume psia = pounds per square inch absolute psig = pounds per square inch gage °R = degree Rankine scf = cubic feet at standard conditions scfh = cubic feet at standard conditions per hour scm = cubic meter at standard conditions scmm = cubic meter at standard conditions per minute sec = second sq ft = square feet std = at standard conditions v/v = volume per volume yd 2 = square yards yr = year

(c) Miscellaneous:

act = actual avg = average I.D. = inside diameter M = molar N = normal O.D. = outside diameter % = percent [59 FR 12430, Mar. 16, 1994, as amended at 67 FR 16598, Apr. 5, 2002]

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