Norsonic delivers several sound calibrators
The most common Norsonic sound calibrators are the Nor1255 and Nor1251. These calibrators are sound pressure
generators. When they are applied on a free field microphone some corrections are needed. Consult the
instruction manual for the sound calibrator if you are in doubt.
Calibrator Nor1251 and microphone Nor1225:
Frequency 1 kHz Level 114 dB
Free field correction: 0,15 dB
Case reflections:-0,1 dB
Multi frequency calibrator Nor1255 and microphone Nor1225:
Frequency 125 Hz, Level 114 dB
Free field correction: 0 dB
Case reflections: 0 dB
Frequency 1 kHz, Level 114 dB
Free field correction: 0.15 dB
Case reflections: -0.1 dB
Frequency 8 kHz, Level 114 dB
Free field correction: 3.4 dB
Case reflections: 0,3 dB
Please note that case reflection does not apply when a microphone extention cable is in use.