Larson Davis SoundAdvisor 831C Reference Manual page 210

L
eq
Level (dB)
Measurement
Duration (T)
SoundAdvisor Model 831C
Table C.4 Frequency Filter Response
Center Frequencies, Hz
1/3 Octave
20
25
31.5
40
50
63
80
100
125
160
200
250
315
400
500
630
800
1000
1250
1600
2000
2500
3150
4000
5000
6300
8000
10000
12500
16000
20000
See "Energy Equivalent Sound Level (Leq)", "Sound", and "Time Weighting".
A descriptor of a measured physical quantity, typically used in sound and
vibration measurements. It is attached to the name of the physical quantity to
denote that it is a logarithmic measure of the quantity and not the quantity itself.
The word decibel is often added after the number to express the same thing.
When frequency weighting is used the annotation is often expressed as dB(A) or
dB(B).
The time period of measurement. It applies to hearing damage risk and is
generally expressed in hours.
Weighting Network Frequency
Response
1 Octave A
-50.4
-44.7
31.5 -39.4
-34.6
-30.2
63 -26.2
-22.5
-19.1
125 -16.1
-13.4
-10.9
250 -8.6
-6.6
-4.8
500 -3.2
-1.9
-0.8
1000 0
0.6
1.0
2000 1.2
1.3
1.2
4000 1.0
0.5
-0.1
8000 -1.1
-2.5
-4.3
16000 -6.6
-9.3
B C
-24.2 -6.2
-20.4 -4.4
-17.1 -3.0
-14.2 -2.0
-11.6 -1.3
-9.3 -0.8
-7.4 -0.5
-5.6 -0.3
-4.2 -0.2
-3.0 -0.1
-2.0 0
-1.3 0
-0.8 0
-0.5 0
-0.3 0
-0.1 0
0 0
0 0
0 0
0 -0.1
-0.1 -0.2
-0.2 -0.3
-0.4 -0.5
-0.7 -0.8
-1.2 -1.3
-1.9 -2.0
-2.9 -3.0
-4.3 -4.4
-6.1 -6.2
-8.4 -8.5
-11.1 -11.2
C-8