BRUEL & KJAER 2209 - Operation; Calibration for Sound Measurements; Using Pistonphone Type 4220 or Sound Level Calibrator Type 4230

3. OPERATION
3.1. CALIBRATION FOR SOUND MEASUREMENTS
3.1.1. Using Pistonphone Type 4220 or Sound Level Calibrator Type 4230
1. Turn the Meter Scale to PRECISION SOUND LEVEL METER.
2. Fit the Attenuator Scale appropriate to the sensitivity of the Con-
denser Microphone in use. Practically any condenser microphone with
200 Volts polarisation can be used, but the Attenuator Scales
appropriate to the suitable 8rliel & Kjrer microphones are shown in
Table 3.1.
Microphone open
circuit Sensitivity
8
& K Microphone Type Scale No.
40- 160 mV per NJm2
4131
4132
1A
(4- 16 mV per bar)
4144 4145
11 - 50 mV per NJm2
18
(1.1- 5 mV per bar)
4- 16 mV per NJm2
2A
(0.4- 1.6 mV per bar)
4133
4134
1.1-5 mV per N/m
2
28
(110- 500 V per bar) 4135 4136
0.4- 1.6 mV per NJm2
3A
(40- 160 V per bar)
4138
Table 3. 1. Attenuator Scales for sound measurements. (see further
Table 6. 1)
15