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2. PRECAUTIONS FOR USE
2.1. PRECAUTIONS FOR USE OF THE SOUND LEVEL METER
We recommend reading these instructions before any use of the instrument.
The sound level meter is a measuring instrument that must be protected from impacts and severe
vibrations
The microphone in particular must be protected from exposure to water and dust, and must not be
stored in a place that is damp and/or too hot
We advise against cleaning the microphone
2.2. REMARK CONCERNING MEASUREMENT CONDITIONS
1. If the difference of level between the absence and presence of the sound to be measured is 10dB
or more, the influence of background noise on the measurement can be regarded as negligible. If the
difference is smaller than this, a compensation correction (see table below) must be applied to the
measurement made to allow for the background noise:
Differences
of level (dB)
4
5
6
7
8
9
10
Compensation
in (dB)
-2.2
-1.7
-1.3
-1
-0.8
-0.7
0
2. The microphone must be placed at a distance from any sound-reflecting surface, such as a wall or
a floor, in order to minimize errors due to possible spurious reflections. During the measurement, hold
the sound level meter at arm's length in order to avoid reflections from your own body, and also to allow
unobstructed propagation of the sound in all directions.
3. Make sure that there is no obstacle between the point of measurement and the source of the noise.
4. Disregard measurement levels that are either too low (sound not significant) or too high (overload).
5. Wind striking the microphone will produce extraneous noise. If the instrument is used in a windy place,
it is best to fit the windscreen ball on the microphone so as not to pick up unwanted signals.