APPENDIX VII
Recommended Unit Symbols, SI Prefixes, and Abbreviations
A.
TABLE I
Recommended Unit Symbols
SI PREFIXES
The following standards provide the recommended abbreviations,
symbols, and units for IEEE publications.
IEEE Standard Dictionary of Electrical and
Electronic Terms, Sixth Edition
IEEE Std 260.1-1993 American National Standard Letter Symbols
for Units of Measurement (SI Units,
Customary Inch-Pound Units, and
Certain Other Units)
IEEE Std 280-1985
American National Standard for Mathematmatical Signs and Symbols for Use
in Physical Sciences and Technology
IEEE Std 280-1985
IEEE Standard Letter Symbols for
(R1997)
Quantities Used in Electrical Science
and Electrical Engineering
IEEE Std 315-1975
IEEE Graphic Symbols foe Electrical and
(R1993)
Electronics Diagrams (Including
Reference Designation Letters)
(Includes supplement 315A-1986, R1993)
SI 10-1997
(IEEE/ASTM) Standard for Use of the
International System of Units (SI) —
The Modern Metric System
When a compound unit is formed by the multiplication of two or
more units, its symbol consists of the symbols of the separate units
joined by a raised dot; for example, N # m for newton meter. When a
compound unit is formed by the division of one unit by another, its
symbol consists of the separate symbols either separated by solidus
(slant) or multiplied using negative powers; for example, either m/s or
m # s-1 for meters per second.
Prefix
Symbol
24
yotta
zetta
exa
peta
tera
giga
mega
kilo
hecto
deka
deci
centi
milli
micro
nano
pico
femto
atto
zepto
yocto
Y
Z
E
P
T
G
M
k
h
da
d
c
m
µ
n
p
f
a
z
y
10
1021
1018
1015
1012
109
106
103
102
10
10-2
10-2
10-3
10-6
10-9
10-12
10-15
10-18
10-21
10-24
IEEE Std 100-1996
The above standards are all available from IEEE, 445 Hoes Lane, P.O.
Box 1331, Piscataway, NJ 08855-1331 USA, Telephone +1-800-678IEEE. Some symbols from these standards are given in Table II of
part C of this appendix. Their form is the same for both singular and
plural usages, and period is not used in their abbreviations. The
distinction between the use of upper-case and lower-case letters should
be carefully observed.
Multiple
B.
Recommended SI Prefixes
Prefixes indicating decimal multiples or submultiples of units and
their symbols are given in Table I. Compound prefixes, such as
“micromicro” for “pico” and “kilomega” for “giga” are discouraged.
C.
Recommended Abbreviations
In general, most abbreviations of technical terms are capitalized,
but there are notable exceptions such as ac, dc, and rms. In addition
to the unit symbols, Table II lists many common technical
abbreviations in their standard IEEE editorial forms. Note that periods
are not used and the abbreviation is the same regardless of whether it
is used as a noun or an adjective. An abbreviation that is new or not
generally accepted should be defined when first used. In abbreviations
involving a person’s name, always capitalize the initial for the person’s
name.
TABLE II
ABBREVIATIONS AND LETTER SYMBOLS FOR UNITS
Unit or Term
alternating current
American wire gauge
ampere
ampere # hour
ampere turn
amplitude modulation
antilogarithm
audio frequency
automatic frequency control
automatic gain control
automatic volume control
average
Abbreviation
ac
AWG
A
Ah
A
AM
antilog
AF
AFC
AGC
AVC
avg
Unit or Term
baud
beat-frequency oscillator
binary coded decimal
bit
British thermal unit
calorie
candela
candela per square foot
candela per square meter
cathode-ray oscilloscope
cathode-ray tube
centimeter
-29-
Abbreviation
Bd
BFO
BCD
b
Btu
cal
cd
cd/ft2
cd/m2
CRO
CRT
cm
TABLE II
(continued)
Unit or Term
circular mil
continuous wave
coulomb
cubic centimeter
cubic foot per minute
cubic meter
cubic meter per second
decibel
degree Celsius
degree Fahrenheit
degree (plane angle)
degree Rankine
degree (temperature interval or difference)
diameter
direct current
electromagnetic compatibility
electromagnetic unit
electromotive force
electronic data processing
electronvolt
electrostatic unit
extra-high voltage
extremely high frequency
extremely low frequency
farad
field-effect transistor
foot
foot per minute
foot per second
foot pound-force
frequency modulation
gallon
gallon per minute
gauss
gigaelectronvolt
gigahertz
gram
henry
hertz
high voltage
hour
inch
inch per second
inductance-capacitance
inertia
infrared
inside diameter
intermediate frequency
joule
joule per degree
kelvin
kiloelectronvolt
kilogram
kilohertz
kilohm
Abbreviation
cmil
CW
C
cm3
ft3/min
m3
m3/s
dB
(C
(F
...(
(R
deg
diam
dc
EMC
EMU
EMF
EDP
eV
ESU
EHV
EHF
ELF
F
FET
ft
ft/min
ft/s
ft # lbf
FM
gal
gal/min
G
GeV
GHz
g
H
Hz
HV
h
in
in/s
LC
kg # m2 or lb # ft2
IR
ID
IF
J
J/deg
K
keV
kg
kHz
k6
Unit or Term
kilojoule
kilometer
kilometer per hour
kilovar
kilovolt
kilovoltampere
kilowatt
kilowatthour
lambert
liter
liter per second
logarithm
logarithm, natural
low frequency
lumen
lumen per square foot
lumen per square meter
lumen per watt
lumen second
lux
magnetohydrodynamics
magnetomotive force
medium frequency
megaelectronvolt
megahertz
megavolt
megawatt
megohm
metal-oxide semiconductor
meter
meter-kilogram-second
microampere
microfarad
microgrm
microhenry
micrometer
micromho
microsecond
microwatt
mile per hour
mile (statute)
milliampere
milligram
millihenry
milliliter
millimeter
millisecond
millivolt
milliwatt
minute (plane angle)
minute (time)
nanofarad
nanometer
nanosecond
nanowatt
-30-
Abbreviation
kJ
km
km/h
kvar
kV
kVA
kW
kWh
L
L
L/s
log
ln
LF
lm
lm/ft2
lm/m2
lm/W
lm # s
lx
MHD
MMF
MF
MeV
MHZ
MV
MW
M6
MOS
m
MKS
µA
µF
µg
µH
µm
µ6-1
µs
µW
mi/h
mi
mA
mg
mH
ml
mm
ms
mV
mW
...’
min
nF
nm
ns
nW
TABLE II
(continued)
Unit or Term
neper
newton
newton meter
newton per square meter
ohm
ounce (avoirdupois)
per unit
phase modulation
picoampere
picofarad
picosecond
picowatt
pound
poundal
pound-force
pound-force foot
pound-force per square inch
pound per square inch§
power factor
radian
radio frequency
radio-frequency interference
resistance-capacitance
resistance-inductance-capacitance
revolution per minute
revolution per second
roentgen
root-mean-square
second (plane angle)
second (time)
Abbreviation
Np
N
N#m
N/m2
6
oz
pu
PM
pA
pF
ps
pW
lb
pdl
lbf
lbf # ft
lbf/in2
lb/in2
PF
rad
RF
RFI
RC
RLC
r/min
r/s
R
rms
...”
s
Unit or Term
short wave
siemens
signal-to-noise ratio
silicon controlled rectifier
square foot
square inch
square meter
square yard
standing-wave ratio
television interference
tesla
thousand circular mils
transverse electric
transverse electromagnetic
transverse magnetic
traveling-wave tube
vacuum-tube voltmeter
var
variable-frequency oscillator
very high frequency
volt
voltage controlled oscillator
voltage standing-wave ratio
voltampere
watt
watthour
watt per steradian
watt per steradian square meter
weber
yard
§ Although the use of the abbreviation psi is common, it is not recommended. See pound-force per square inch.
-31-
Abbreviation
SW
S
SNR
SCR
ft2
in2
m2
yd2
SWR
TVI
T
kcmil
TE
TEM
TM
TWT
VTVM
var
VFO
VHF
V
VCO
VSWR
VA
W
Wh
W/sr
W/(sr # m2)
Wb
yd