OSCILLA SM930 Calibration Manual

ID: 984 / ver. 204
2
General information:
Due to tolerances in electronics and transducers (telephones and bone conductor), it is necessary to calibrate
the sound level to the correct intensity. Calibration is done with the transducers that belong to the
audiometer. If a transducer is replaced the audiometer has to be calibrated with the new transducer.
The device has a built-in table for the ISO hearing level offsets (called RETSPL values). These offsets
are added to the displayed sound level when the device is in normal operation mode, to obtain the ISO
hearing level. When in calibration mode these offsets are not effective. Therefore all frequencies should
be calibrated to equal levels, namely 80dB. This makes it easy and quick to perform the calibration.
Remember to add the correction factors for the calibration microphone.
Entering calibration mode:
To enter the calibration mode, hold down the ‘ATTENUATOR DOWN’, ‘TONE’ and
‘FREQUENCY DOWN’ keys and switch on the audiometer. Wait about 2 seconds and release the
three buttons. The ‘RESPONSE’ light will now flash five times and then stay on. The audiometer is
now in calibration mode.

OSCILLA SM930 Specifications

General

Brand	OSCILLA
Model	SM930
Category	Measuring Instruments
Language	English