SoundAdvisor Model 831C
A-7
A.1.16 Data Storage Specifications
Internal
: 2 GB non-volatile flash memory dedicated to
data and user setups
External: Up to 32 gigabyte USB Flash Memory Drive
A.1.17 Electrostatic Discharge Specifications
The instrument is not adversely affected by
electrostatic discharges.
A.1.18 Environmental Conditions Specs
Operating Temperature
: –30 to +50°C (–22 to 122°F)
Storage Environment
: –30 to +60° C (–22 to +158°F),
less than 90% RH
Temperature Sensitivity
: ≤ 0.5 dB sensitivity, –10 to
+50°C (14 to 122°F) at 1kHz
Humidity Sensitivity
: ≤ ±0.5 dB sensitivity, 25% to 90%
relative humidity at 40°C (104°F) at 1kHz
A.1.19 Physical Characteristics
Dimensions
:
• 290 x 71 x 41 mm (11.35") including
microphone and preamplifier
• 224 x 71 x 41 mm (8.80") instrument body
only
Weight
:
• 531.6 g (18.8 oz) including batteries,
preamplifier and microphone
• 489.2 g (17.3 oz) including batteries
A.2 Model PRM831
The Larson Davis PRM831 is an electret microphone preamplifier for use with a Larson Davis Model 831 Sound Level Meter. It
requires little supply current and is capable of driving 300 feet of cable. The preamplifier operates over wide ranges of
temperature and humidity. It has very little attenuation for use with 50 mV/Pa sensitivity microphones up to 140 dBSPL.
A.2.1 Model PRM831 Specifications
Frequency response
With respect to the response at 1 kHz with 1 Volt rms input
and 12 pF equivalent microphone, the frequency response is
as follows:
8 Hz to 16 Hz +0.1, -0.2 dB
16 Hz to 100 kHz +0.1, -0.1 dB
Lower -3 dB limit < 1.5 Hz
Attenuation
0.1 dB (typical)
Input Impedance
10 G Ohm // 0.16 pF
Output Impedance
50 Ohm
Maximum Output
28 Vpp
143 dB peak for microphones with 50 mV/Pa sensitivity
Maximum Output Current
12 mA peak
Distortion
Harmonics <-70 dBC with 8 Volt rms output at 1 kHz
Output Slew Rate
2 V/µS (typical)
Electronic Noise
with 12 pF equivalent microphone
1.8 µV typical A-weighted (2.4 µV max)
4.3 µV typical Flat 20 Hz to 20 kHz (5.0 µV max)
Power Supply Voltage
15 to 36 Volts
DC Output Level
~1/2 power supply voltage
Power Supply Current
1.9 mA typical
