Company Writer's Guide
[For Illustration Only] B-15
Symbols for Units in General Use (Cont’d)
Unit Symbol Notes
pound-force foot lbf-ft
pound-force per square foot lbf/ft
2
pound-force per square inch lbf/in
2
Although use of the abbreviation psi is common,
it should not be used as a symbol.
poundal pdl
quart qt
1 qt (UK) = 1.136 5 L
1 qt (US dry) = 1.101 2 L
1 qt (US liquid) = 0.946 35 L
rad rd
A unit of absorbed dose in the field of radiation
dosimetry. Use of the SI unit, the gray, is
preferred. 1 rd = 0.01 Gy.
radian rad SI unit of plane angle.
rem rem
A unit of dose equivalent in the field of radiation
dosimetry. (Use of the SI unit, the sievert, is
preferred. 1 rem = 0.01 Sv)
revolution per minute r/min
Although use of rpm as an abbreviation is
common, it should not be used as a symbol.
revolution per second r/s
roentgen R
A unit of exposure in the field of radiation
dosimetry.
second (plane angle) . . . ′
second (time) s SI unit of time.
siemens S 1 S = 1 Ω
-1
SI unit of conductance. The name mho has been
used for this unit in the USA.
sievert Sv
SI unit of dose equivalent in the field of radiation
dosimetry. Name adopted by the CIPM in 1978.
slug slug 1 slug = 14.5039 kg
