Svantek SVAN 979 - Page 263

263
SVAN 979 User Manual - Appendixes
Calibration
Acoustical - with the SV 36 sound calibrator (or equivalent):
• Calibration level for the pressure field
114.0 dB (equal to the calibrator pressure level - see calibration
chart of the used calibrator)
• Calibration level for the free field and
0 deg incidence angle
113.87 dB (equal to the calibration level for the pressure field
minus free field correction of G.R.A.S. 40AE at 1000 Hz – see
Table C.1.6)
Note: The above levels correspond to 114 dB of calibrator’s sound pressure. If the calibrator has
a different sound pressure than 114 dB, the calibration levels must be accordingly adjusted.
Microphone
G.R.A.S. 40AE prepolarized free-field ½” condenser microphone
Nominal sensitivity 50 mV/Pa (corresponding to -26 dBV/Pa re 1 V/Pa)
Capacitance 17 pF.
Note: Maximum level of sound pressure level, which can be affect the microphone without destruction
the microphone: 148 dB.
Table C.1.6. G.R.A.S. 40AE free field correction for electrostatic actuator the 0 deg incidence
Correction
factors
[dB]
Frequency [Hz]
20
25
31,5
40
50
63
80
100
125
160
200
250
315
400
500
630
800
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.1
0.08
0.07
0.08
0.18
Frequency [Hz]
1000
1250
1600
2000
2500
3150
4000
5000
6300
8000
10000
12500
16000
20000
0.13
0.05
0.19
0.45
0.58
0.8
1.11
1.68
2.58
3.78
5.06
6.83
8.29
9.49
40AE Free field / Actuator
-15,00
-10,00
-5,00
0,00
5,00
10,0 100,0 1000,0 10000,0 100000,0
Frequency (Hz)
R
e
s
p
o
n
s
e
(dB)
Free field - calcula ted
Electrosta tic actuator