For example, set the sensitivities of the MI-1233 Microphone and MI-3110 Preamplifier as follows.

 

Sensitivity of MI-1233 Microphone (from the data sheet)	35 mV/Pa, -29 dB (0 dB = 1 V/Pa) (effective value)
Gain of MI-3110 Preamplifier	-3 dB

 

When the standard sound pressure of "94 dBspl (1000 Hz ± 10 Hz)" from the SC-2120 Sound Calibrator is given to the microphone, the theoretical value of the voltages which is inputted to the DS-2000 is as follows.

 

The signal is outputted from the MI-1233 Microphone (-29 dB) and passed through the MI-3110 Amplifier (gain -3 dB) and inputted to the DS-0221. So the input voltage can be obtained as follows;

 

-29 + (-3) = -32 dBV (effective value)

 

When the unit calibration of the DS-0221 FFT analysis software is turned OFF (When the unit calibration is turned ON, set the calibration value to 1.000 V/ EU), the value of power spectrum is as follows;

 

Power spectrum: -32 dBV ± 0.5 dBV
(± 0.5 is margin for the environmental condition, effective value)

 

When the SC-3100 Sound Calibrator (Standard sound: 124 dBspl, 250 Hz ± 1 Hz) is used, the value of power spectrum is as follows;

 

Power spectrum: -2 dBV ± 0.5 dBV
(± 0.5 is margin for the environmental condition, effective value)

 

Daily inspection is to check if the measured value is similar to above values or not.

Precise inspection for the MI-1233 Microphone can be operated at Ono Sokki based on "JCSS". Please contact your nearest distributor or send us an e-mail.