[Code of Federal Regulations]
[Title 40, Volume 9]
[Revised as of July 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR63.3]

[Page 18-19]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 63--NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES--Table of Contents
 
                      Subpart A--General Provisions
 
Sec. 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
 deg.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
[ohm] = ohm
[micro]g = microgram = 10-6 gram
[micro]l = microliter = 10-6 liter

    (b) Other units of measure:

Btu = British thermal unit
  deg.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
  deg.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
 deg.R = degree Rankine
scf = cubic feet at standard conditions

[[Page 19]]

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]