Environmental Engineering Reference
In-Depth Information
Table A.4
Prefixes of the SI International System of Units ((Système International d'Unités)
Factor
Name
Symbol
10
18
Exa
E
10
15
Peta
P
10
12
Tera
T
10
9
Giga
G
10
6
Mega
M
10
3
Kilo
K
10
2
Hecto
H
10
Deca
Da
10
-1
Deci
d
10
-2
Centi
c
10
-3
Milli
m
10
-6
Micro
l
10
-9
Nano
n
10
-12
Pico
p
10
-15
Femto
f
10
-18
Atto
a
Table A.5
Units of concentration
Name
Symbol
Definition
Percent parts per hundred
%
10
-6
Parts per million
ppm (v)
to volume
10
-6
Parts per million
ppm (m)
to mass
10
-9
Parts per billion
ppb
10
-12
Parts per trillion
ppt
Table A.6
Conversion factors
10
6
10
6
t ROU
Crude Oil Unit
Unit
PJ
TWh
t CU coal unit
1 Petajoule (PJ)
1
0.2778
0.0341
0.0239
1 Terawatt hour (TWh)
3.6
1
0.123
0.0861
10
6
t CU
29.308
8.14
1
0.7
10
6
t ROU
41.69
11.63
1.429
1
