Instruction Manual

Sound Level Meter Types 2245 – Instruction Manual Page 17 of 110
10. Press the button to accept the calibration and remove the calibrator. It will
automatically switch off after a few seconds.
If no calibration signal is detected, you will be informed about an unstable calibration
signal and asked to mount the calibrator, switch it on and press Retry to restart the
calibration.
If the calibration deviates more than ± 1.5 dB (± 1.1 dB in Spain) from the initial
calibration, then the calibration is stopped without changing the calibration of the
sound level meter.
You can verify the calibrations made by navigating from the main menu: Calibration
history > Calibrations >
2.4.2 Calibration Check Procedure
It is good practice to perform regular checks of the calibration, normally before and
after each set of measurements. This can easily be done without changing the
calibration. The sound level meter keeps a history of all the checks.
Use Sound Calibrator Type 4231. It provides a stable sound pressure at 1 kHz and has
minimal susceptibility to environmental factors.
Kræver Automatic check enabled
To perform an acoustic check of the calibration:
1. Stand away from loud sound sources that may interfere with the calibrator’s
signal.
2. Switch on the sound level meter.
3. Be sure that the instrument doesn’t measure or is paused but is stopped and
reset (press ) – and is on a measurement screen (not in settings).
4. Fit Sound Calibrator Type 4231 carefully onto the microphone of the sound
level meter. To avoid handling vibrations that disturb the calibration, rest the
assembly in a roughly horizontal position on a table or other flat surface.
Ensure that the calibrator fits snugly on the microphone.
5. Switch on the calibrator. Wait a few seconds for the level to stabilize.