HP RM500SL manual Calibration check for probe module

10.4 Calibration check for probe module

The calibration curve for the probe module is a comparison of the response of the probe microphone (with tube) to the response of the REM reference microphone. Any change in the curve indicates a change in one of these microphones (or the probe tube). See 10.3: Calibration of REM probe microphone. As part of a regular calibration schedule, or to investigate changing calibration curves, the REM reference microphone may be checked against a high quality sound level meter.

1)Press <Tests>, then highlight and <PICK> REM [Manual control].

2)Highlight & <PICK> [Level], then highlight & <PICK> 70 from the drop-down list.

3)Highlight and <PICK> [Frequency], then highlight and <PICK> 2000 Hz from the drop-down list.

4)Highlight, then <PICK> [Start test] (which changes to [Stop test]).

5)Hold the probe module about 18” (0.5 m) in front of the REM speakers.

6)Hold the microphone of a calibrated sound level meter next to the REM reference microphone as shown. Set the sound level meter to C weighting and slow.

7)The sound level meter should read 70 ±2 dB.

8)Repeat with the frequency at 250 Hz.

9)To stop the measurement, highlight and <PICK> [Stop test].

The probe module should be replaced if it fails this test.

FastFacts 10.4: Calibration check for probe module

0611 RM500SL User’s Guide Version 2.8 Page 52