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4.7
Activation / deactivation of the automatic shut off
By default, the automatic shut off mode is activated when you switch on your unit. The
instrument will switch off automatically after 30 minutes if none of the buttons is pressed, no
recordings are being made or if none of the USB links is activated.
If you wish to deactivate automatic shut off:
- Turn off the sonometer.
- Hold the “ON/OFF” and “FAST/SLOW” push buttons pressed.
4.8
Calibration of the sonometer
If you have not made any measurements for some time, it is advisable to check the calibration
of your sonometer. To do this, use the CA 833 sonometer calibrating instrument.
The procedure is as follows:
- Turn on the sonometer
- Set it to the high measurement range: 80 – 130 dB
- Select the weighting curve A
- Select the fast response time «FAST»
- Insert the microphone as deep as possible into the calibrating instrument
- Place in the assembly on a flat surface that is free of vibration.
- Switch on CA 833 set to the 94 dB position
- Set the sonometer display to 94 dB using the screw
and the screwdriver supplied
with the instrument.
- After adjustment, check your calibration with CA 833 set to 114 dB.
5. GENERAL CHARACTERISTICS
- Compliance with standards :
IEC 651 type 2
ANSI S1.4
JIS C 1502
- Type of microphone :
condenser microphone
- Measuring range :
4 measuring ranges from 30 to 130dB
30-80dB
50-100dB
80-130dB
30-130dB (automatic change of range)
- Display :
LCD screen
Digital :
4 digits
Resolution : 0.1dB
Display update : 0.5s
Analogue :
50 segment bargraph
Resolution : 1dB
Display update : 50ms
