Company Writer's Guide
[For Illustration Only] B-5
Symbols for Units in General Use (Cont’d)
Unit Symbol Notes
bel B
becquerel Bq SI unit of activity of a radionuclide.
billion electronvolts GeV
The name gigaelectronvolt is preferred for this
unit.
bit b
In information theory, the bit is a unit of
information content equal to the information
content of a message the a priori probability of
which is one half.
In computer science, the bit is a unit of storage
capacity. The capacity, in bits, of a storage
device is the logarithm to the base two of the
number of possible states of the device.
bit per second b/s
British thermal unit Btu
calorie
(International Table calorie)
cal
IT
1 cal
IT
= 4.1868 J (deprecated, see ANSI Z210.1-
1976)
calorie
(thermochemical calorie)
cal
1 cal = 4.1840 J (deprecated,
see ANSI Z210.1-1976)
candela cd SI unit of luminous intensity.
candela per square inch cd/in
2
Use of the SI unit, cd/m
2
, is preferred.
candela per square meter cd/m
2
SI unit of luminance. The name nit is sometimes
used for this unit.
candle cd
The unit of luminous intensity has been given
the name candela; use of the name candle for this
unit is deprecated.
centi c SI prefix for 10
-2
.
centimeter cm
