BSWA 308 - Process of Calibration by Measurement

BSWA 308/309 BSWA Technology Co., Ltd
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Cal.F = 20 * log (Sens / 40) + offset
Sens = 40 * 10
((Cal.F-offset) / 20)
Where:
Cal.F is the calibration factor, expressed in decibels (dB);
Sens is sensitivity of microphone, expressed in mV/Pa;
offset is the calibration factor, expressed in decibels (dB). This value is the calibration
result by the method of By Measurement with 40mV signal. This offset is inherent deviation
which is different for each sound level meter.
4.2.4 Process of Calibration by Measurement
Calibration by measurement is the recommend method of calibration with sound calibrator.
BSWA can provide class 1 and class 2 sound calibrator comply with the GB/T 15173-2010,
IEC60942: 2003 standard.
The process of calibration by measurement is shown as following:
(1) Insert the microphone into the cavity of the calibrator until stop without loosening.
(2) Then open the power of the calibrator and set to a constant sound pressure level (for
example 94dB).