Instruction manual

37
Calibration
Acoustic calibration (with sound calibrator)
For acoustic calibration, a sound calibrator is mounted to the microphone of
the sound level meter, and adjustment is performed so that the reading of the
meter is equal to the sound pressure level inside the coupler.
1. Turn off the Sound Calibrator NC-74.
2. Mount the 1/2-inch adapter on the coupler of the Sound Calibrator
NC-74.
3. Insert the microphone very carefully and slowly all the way into
the coupler.
Important
Be very careful when inserting and removing
the microphone to and from the sound calibra-
tor NC-74, to avoid a sudden pressure buildup
which could destroy the membrane of the mi-
crophone.
4. Set the power switch of the Sound Calibrator NC-74 to ON.
1/2-inch adapter
for NC-74
Sound Calibrator NC-74