4.1. PROCEDURE
1. Selection of measurement range
The sound level meter features 3 measurement ranges each having a dynamic
range of 55 dB :
Low noise range level :
Medium noise range level :
High noise range level :
When noise measurement is active, the measurement is repeated more than 2
times per second.
If the
or
arrows are shown continuously on the display, this means that the
measurement range you are in is too high or too low. In this case, press the RANGE
button until you return to the adequate measurement range.
2. Choice of frequency weighting :
Since the ear does not have the same hearing sensitivity for all frequencies, filters
are used which weight or correct the measurement levels according to frequency.
Two correction curves A and C are on the C.A 832. To switch from one to the other
a long press is needed ( > 2 seconds ) on the push button
The most common is weighting curve A corresponding to the "average international
ear". It is usually used for the measurement of nuisance levels in industrial areas.
Curve C is more suited for verification of the presence of low frequency noise (if the
measurement level on position C is higher than on position A, this means that the
signal contains significant low frequency components).
This curve is well suited for the measurement of musical environments.
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 C.A 832:
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. UTILISATION
37 to 80dB
50 to 100dB
80 to 130dB
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