Cirrus Optimus+, Instrument Handbook

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Page 44
Sound Level Meters – User Manual
9 Acoustic calibrator information
This chapter refers to the use of a Cirrus Research plc CR:514 or CR:515 acoustic calibrator.
9.1 Setting up the calibrator
Press the power button on the end of the calibrator to switch the unit on. The indicator will
illuminate to show that the unit is operating. The calibrator will automatically switch off after five
minutes to preserve battery power.
To switch the calibrator off manually, press
the power button again and the indicator
will extinguish to show that the unit is
switched off.
Permanent-on mode
For some applications there may be a need to have the calibrator switched on continuously. To
allow for this, the calibrator can be turned on by pressing and holding the power button for three
seconds. Release the button and the indicator will flash to show that the unit is in permanent-
on mode. Press the power button again to switch off the calibrator.
9.2 Calibrating a sound level meter
Push the microphone of the sound level meter into the cavity at the end of the calibrator. Ensure
the microphone is fully inserted into the cavity and is past the ‘O’ ring seals.
The microphone should be parallel to the body of the calibrator. Also ensure that the small bleed-
hole next to the microphone cavity is not blocked as this could cause damage to the microphone.
Power button
Power indicator