Larson Davis SoundAdvisor 831C Reference Manual page 201

f) Linear Operating Range
Table B.3 Linear Operating Range
Gain 31.5 Hz
0 dB 22.6 dB to 100.5
20 dB 18 dB to 80.5 dB
g) Linear Measurement Starting Point
Table B.4 Linear Measurement Starting Point
Gain 31.5 Hz
0 dB 74.5 dB
20 dB 54.5 dB
h) Electrical Insert Signals
The electrical design of the input device to insert electrical signals into the preamplifier is a series 12pF ±
5% capacitor. The Larson Davis ADP090 is used for this purpose. The ADP090 is also use for noise floor
measurements by attaching the included BNC short on the front of the ADP090.
i) Self Generating Noise in Low Level Sound Field
Table B.5 SLM Noise Levels
Self Generated Electrical
Self Generated Total Noise
Note: Combination of the electronic noise and the thermal noise of the 377B02
j) Highest Sound Pressure Level
The highest sound pressure level the Larson Davis 831C is designed to accommodate at the level of
overload is 140 dB. The maximum peak-to-peak voltage is 28 Vpp input through the ADP090.
SoundAdvisor Model 831C
1 kHz
22.6 dB to 140
dB dB
18 dB to 120 dB
1 kHz
114 dB
94dB
Noise
Weighting Typical (dB)
A
C
Z
Weighting Typical (dB)
A
C
Z
microphone at 68 °F (20 °C) measured in a sealed and vibration isolated cav-
ity with an averaging time of 60 seconds. Electronic noise of the instrument
with an ADP090 (12 pF) in place of the microphone highest anticipated self-
generated noise.
4 kHz
22.6 dB to 141
dB
18 dB to 121 dB
4 kHz
115 dB
95 dB
0 dB Gain
Max (dB) Typical (dB)
10 12
13 16
22 25
0 dB Gain
Max (dB) Typical (dB)
16 19
17 20
23 26
8 kHz 12.5 kHz
22.6 dB to 138.9 22.6 dB to 135.7
dB
18 dB to 118.9 18 dB to 115.7 dB
dB
8 kHz 12.5 kHz
112.9 dB 109.7 dB
92.9 dB 89.7 dB
20 dB Gain
Max (dB)
6 9
12 15
22 25
20 dB Gain
Max (dB)
16 17
16 19
23 26
dB
B-6