Larson Davis Spartan 821 - Page 74

Spartan 821/721 Manual Octave Band Analysis Specifications A-27
Instrument Noise Levels With OBA
The following charts show the 721 and 821 typical instrument noise levels for the OBA filter
with the PRM721 or PRM821.
FIGURE A-11 Self-Generated Noise Levels for 1/1 Octave Filter With PRM821 or PRM721
FIGURE A-12 Self-Generated Noise Levels for 1/3 Octave Filter With PRM821 or PRM721
8
16
31.5
63
125 250 500
1000 2000 4000 8000
16000
0
5
10
15
20
dBre20µPa
Frequency(Hz)
6.3
8
10
12.5
16 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
‐5
0
5
10
15
dBre20µPa
Frequency(Hz)