Appendix BUNITS OF MEASUREMENT
Name
Abbreviation
Unit of
Equivalent or definition
atmosphere
atm
1 atm is normal atmospheric pressure
1 atm = 1.013 x 10^{5} N/m^{2} = 1.013 bar = 14.7 lbs/in^{2}
bar

1 bar = 10^{6} dynes/cm^{2} = 10^{6} µbar = 0.9869 atm
bel

see decibel below
cent

frequency ratio
(interval)
1 cent corresponds to a frequency ratio of 2^{1/1200}
100 cents = 1 semitone
1200 cents = 1 octave
cycles per second
cps
1 cps = 1 Hz (see hertz below)
dB
1 dB = 0.1 bel = log I_{1}/I_{2} where I_{1} = 10.I_{2}
dyne
dyn
force
1 dyn = 10^{5} N = 1 gm cm/sec^{2}
erg

energy
1 erg = 10^{7} J = 1 gm cm^{2}/sec^{2}
gigahertz
gHz
1 gHz = 10^{9} Hz = 10^{3} mHz = 10^{6} kHz
hertz
Hz
1 Hz = 1 cycle/sec = 1 cps
1000 Hz = 1 kHz = 1 kc
joule
J
energy
1 J = 10^{7} erg = 1 kg m^{2}/sec^{2}
kilocycle
kc
1000 cycles
1 kilocycle/sec = 1 kc = 1000 cps = 1 kHz
kilohertz
kHz
1 kHz = 1000 Hz
megacycle
mc
10^{6} cycles
1 megacycle/sec = 1 mc = 10^{6} cps = 1 mHz
megahertz
mHz
1 mHz = 10^{6} Hz = 10^{3} kHz

1000 Hz at 40 dB is defined as 1000 mels
microbar
µbar
1 microbar = 10^{6} bar = 1 dyne/cm^{2}
Threshold of Hearing is 2 x 10^{4} µbar
microsecond
µsec
time
1 µsec = .001 ms = 10^{6} sec

distance (thickness)
1 mil = .001 inch
millisecond
ms
time
1 ms = .001 sec
Newton
N
force
1 N = 10^{5} dyn = 1 kg m/sec^{2}

Pascal
Pa
1 Pa = 1 N/m^{2} = 10^{6} µPa

See: PHON, EQUAL LOUDNESS CONTOURS
sabin

1 sabin is equivalent to 1 squre foot of a surface absorbing all incident energy

1 sone = 40 phons
watt
w
energy flow or power
1 watt = 1 joule/sec
* The terms kilocycle and megacycle, just as the basic term cycle, are often used loosely meaning frequency units. Proper frequency specification would be cycles/sec, kilocycles/sec, megacycles/sec. Partly due to this ambiguity, ther terms hertz, kilohertz and megahertz have been introduced as standard units of frequency.
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