Service Manual
AT235
24
4.1.6 Calibration standard for Audiometer
This chapter contains calibration standards for the Audiometer. Included here is an explanatory guide and a
complete set-up of how to calibrate each transducer type.
Tone standard
is selected via AUD and ‘
Standard’
. The options are IEC or ANSI.
Calibration method
is selected via AUD and
‘Calibration method’.
The options are SPL mode or HL mode.
SPL mode
In SPL mode, the attenuator is adjusted according to the standard correction for each stimuli and frequency. In
that way the target level can be the same SPL level for all stimuli, and the microphone correction is the only thing
that should be added.
HL mode
In HL mode, the attenuator values are rounded and the target level in SPL varies and will be similar to the values
known from older HL-calibrated devices. The standard correction will be reflected as the difference between the
given HL and SPL level. Microphone correction should be added to the target level.
Fig. 40
