Attenuator Maximum Output Level Calibration (D4) - Welch Allyn Grason-Stadler GSI 17 Series Service Manual

4.9.5 ATTENUATOR MAXIMUM OUTPUT LEVEL CALIBRATION (D4)

If Default
NOTE:
performed before calibration of earphones.
TEST DISCR I P T I O N
If the Microprocessor of the GSI 17 has been replaced or a major
calibration data loss has occurred the Attenuator Maximum output
level must be calibrated.
operator will measure the output level on the connector
(important -unloaded)
adjust the attenuator position until correct output voltage is
The calibration data is then stored and the process is
measured.
repeated for all remaining stimuli.
calibrated in any order, but all must be calibrated.
all output levels were adjusted to 2.5 vrms *.15 vrms for each
The newer GSI 17's have specific maximum output
frequency.
levels for calibration.
outlined below.
NOTE When performing this procedure, output must be unloaded
:
(no phone plugged in).
SERIAL NUMBERS LESS THAN 1230 (EXCLUDING 1068, 1175r AND 1212)
All frequencies 2.5 vrms (+.15 vrms)
SERIAL NUMBERS GREATER THAN 1230 (INCLUDING 1230, 1068, 1175, AND 1212) _
Frequency (Hz)
125
250
500
750
1K
2
3
4
6 K
8
Data is loaded,this
When performing this calibration, the
of the currently selected transducer
Serial numbers and output levels are
K
K
K
K
procedure
The stimuli may be
Voltage (rms) (2.5
2.30
2.30
2.15
1.90
2.50
2.50
2.50
2.50
2.50
2.50
must be
and
Originally
dB)