Calibration Check For Coupler Microphone - audioscan RM500SL User Manual

Calibration check for coupler microphone

Accuracy of test box measurements depends on the calibration of the coupler microphone.
This should be checked regularly using a microphone calibrator with an adapter ring. The
RE780 (1 1/8") and RE781 (1") rings are designed for Quest CA22 and QC-10/20
respectively. To verify the coupler microphone calibration:
1. Calibrate the test box reference microphone. See Calibrating test box reference
microphone
2. Screw the appropriate calibrator ring onto the coupler microphone.
3. Insert the coupler microphone with the attached calibrator ring into the calibrator
opening.
4. Turn the calibrator on and adjust it to present one of the available frequencies and levels
(e.g., 94 dB SPL at 1000 Hz).
5. Press <Tests>, then highlight and <PICK> [Test box measures], then highlight and
<PICK> [Manual control].
6. Highlight and <PICK> the [Level] window, then highlight and <PICK> 0 from the drop-
down list.
7. Highlight, then <PICK> the [Frequency] window, then highlight and <PICK> the
frequency of the calibrator (e.g. 1000 Hz) from the drop-down list.
8. Highlight, then <PICK> the [Filter] window, then highlight and <PICK> 1/12th octave
from the drop-down list.
9. Highlight, then <PICK> [Start test] (which changes to [Stop test]).
10.Check that the Coupler microphone level is within 1 dB of the calibrator level setting,
+/- the calibrator accuracy.
indicated coupler microphone level should be 94 +/- 1.3 dB.
11.To stop the measurement, highlight and <PICK> [Stop test].
User's Guide Version 3.4 © June 2011
RM500SL ®
For a 94 dB calibrator with +/- 0.3 dB accuracy, the
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