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3. Choice of response time.
Depending on the nature of the noise under consideration (brief noises
such as a horn or an animal cry or prolonged noise such as industrial
machinery), we must choose an adequate measurement response time.
Two response times are available on the CA832:
F (short response time filter) if the noise is made up of brief pulses or if
only the peak values interest you. It is the most commonly used.
S (long response time filter) to measure a medium sound level.
The 3-position centre switch is used to cut from one to the other.
4. Practical measurement conditions :
Hold the instrument in the hand and direct the microphone towards the
source of noise to be measured (see precautions for use); the sound level
will be displayed.
5. MAX Mode : press the MAX push button to display the maximum
sound level during the measurement period.
6. Switch off the instrument (position OFF) after use.
4.2 Utilisation of the auxiliary output and of the
assembly screw for photo stand.
• Utilisation of analogue output.
The CA 832 sound level meter possesses a physical output capable of
supplying an AC or DC signal proportional to the sound level in dB, usable
via external long running recording equipment for example.
AC output: supplies approximately 1Vrms at maximum of the scale used.
DC output: supplies 10 mV/dB
Utilisation of the ‘Jack’ connector: solder the ‘common’, ‘AC signal, DC
signal’wires onto the ‘Jack’male connector.Insert the latter in to the female
connector located at the bottom of the sound level meter casing.
• Mounting the sound level meter onto a photo tripod
For long-duration measurements, the sound level meter can be mounted
on a tripod (not included).To do so install the assembly screw (10) for the
tripod at the rear of the sound level meter.
Install the tripod.
4.3 Calibration of the sound level meter
Calibrate the instrument before its use, in particular if you have not
performed any measurements for a long period. To do so, use the sound
level meter CA 833 calibrator.
The procedure is as follows:
1. Switch on the sound level meter.Select the high measurement range
80-130 dB , on curve ‘C’ and on temporal filter ‘F’
2. Remove the foam protection of the microphone, then insert the
microphone into the female part of the calibrator until it stops. Set the
assembly on a flat surface, not subject to vibrations.
