Civil Engineering Reference
In-Depth Information
Table 2.1
SI base and
supplementary units
Quantity
Unit
Symbol
Length
meter
m
Mass
kilogram
kg
Time
second
s
Electric current
Ampere
A
Thermodynamic temperature
Kelvin
K
Luminous intensity
candela
cd
Molecular substance
mole
mol
Plane angle
radian
rad
Solid angle
steradian
sr
Table 2.2
Prefixes
commonly used
Factor
Prefix name
Symbol
Multiple
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
1
deka
da
Submultiple
10
1
deci
d
10
2
cents
c
10
3
milli
m
10
6
micro
μ
10
9
nano
n
10
12
pico
p
10
15
femto
f
10
18
atto
a
factors of the single units. This is valid also for temperature, if temperature changes
are considered (as often occurs in many formulas).
Table
2.5
lists some parameters frequently used for technical calculations.
2.2
Primary Energy Measurement Units
The primary energy content of combustibles (solid, liquid, or gaseous) is expressed
by Lower Heating Values or Higher Heating Values such as kJ/kg or kJ/m
3
(SI units). There are other units in common use.
