Brüel & Kjær 3638 Manuel De L'utilisateur page 29

Fig.4.2 Calibration window of Mediator Type 2238
Mediator Type 2238
4) Set the calibration Level on the sound level meter to 93.9 dB using its
Mediator Type 2238, press Calib. at the top of the screen, using the arrow keys and
to confirm.
5) Switch on the calibrator. Type 4231 automatically emits a 1 kHz signal at 94 dB. Wait
approximately 5 seconds for all levels to stabilise.
6) Press on the calibrator to calibrate your sound level meter. Wait until the calibration is
finished. (During calibration, press
calibration.)
7) With Mediator Type 2238, if the calibration is successful a calibration result window will
appear similar to below:
If the New Sens. value is within an acceptable deviation level from the Curr. Sens.
value (maximum: ±1.5 dB), select Accept at the top of the screen and press
firm. The Init. Sens. value is the factory sensitivity value, and allows you to evaluate
the absolute deviation since the instrument was manufactured.
Press Cancel if you cannot accept the New Sens. value or if a calibration error warning
appears (deviation too large). A new calibration must be performed. In this case:
• Check that the microphone has been fitted properly in the calibrator
• Check that the microphone is fully screwed on to the extension cable
• Check that the calibrator has been switched on and is working properly
• Check that the calibration level has been entered correctly
• External noise or vibrations may have affected the calibration
• Inspect the microphone to see if it has been damaged
8) When calibration is finished (and you have accepted the results), press
main screen.
CALIBRATION
Level: > 94.0 dB
Current Factor:
0.0 dB
Type 2239 A
on the sound level meter if you need to abort
PART 1
25
English
keys. With
to con-
to return to the