Characteristics; Influence Of Ambient Pressure - HBK 4231 Manuel De L'utilisateur

3.1

Influence of Ambient Pressure

For normal use, the influence of atmospheric pressure on the sound
pressure level produced by the calibrator is so small that you can ignore it.
Fig.3.1 shows the effect that variations in atmospheric pressure have
on the sound pressure level produced. It is a linear relationship caused
by changes in the sensitivity of the calibrator's reference microphone
which varies directly with changes in static pressure.
Fig.3.1 Typical variation of sound pressure level as a function of static pressure at 23 °C
Calibra on devia on in dB
0.05
50
Typical
– 0.04
– 0.05
60 70
65
Sound Calibrator Type 4231
User Manual
Chapter 3

Characteristics

Calibra on point
80 90
IEC 60942
Specifica on range
101.3 kPa
Atmospheric
pressure
in kPa
100 110
108
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