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4.5
Measurements of low-level sounds
The self-generated noise level for the most sensible ranges of S51 is
below (but near to) 20 dBA, 23 dBC or 38 dBG. This must be
considered when measuring low-level sounds. The self-generated
noise and the measured sound can be considered as uncorrelated and
don’t add directly to each other. The self-generated noise level for
the less sensible ranges is higher but is at least 5 dB below the low
end of the range.
Measured level = 10
*
log
10
(10
(noise/10)
+ 10
(sound/10)
) [dB]
Example:
noise level = 20 dB, sound level = 23 dB
measured level = 24.8 dB
Influence by the self-generated noise level, as function of the difference between
the sound level and the noise level.
