Cirrus Optimus Green Series, Instrument Hanbook

Page: 14 / 56

Optimus sound level meter - instrument handbook
14
Take care not to use a twisting motion when pushing the microphone into the calibrator,
as this is likely to cause damage to the preamplifier (as described earlier in this chapter).
Press the ‘on’ button on the end of the calibrator. Press the calibrate button on the
Optimus.
The instrument will measure the sound level from the acoustic calibrator to determine
if it is within the required tolerance and levels. The calibration level must be stable to
within ±0.075 dB for 5 consecutive seconds, for the calibration to be successful.
When the calibration is complete, the Optimus will display the level along with the
correction or adjustment made.
The Optimus is preset with the correction values needed for Cirrus Research
microphone capsules, so no manual adjustment is required. The calibration level you
should expect is 93.7 dB.
Refer to page 44 for detailed operating information for the CR:514 and CR:515 acoustic
calibrators.