Sigicom 080-02850-0, Руководство пользователя

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where the S50 is mounted far away from any object. However, the
higher frequencies of the sound pressure level are damped, because
their wavelength will be in the same magnitude as the distance
between the microphone and the wall. The figure below shows the
measured sound pressure level of sinusoidal sound waves
propagating perpendicular towards a wall (with perfect reflection) as
function of the frequency levels for the distances 6, 15 and 17 mm
between the center of the microphone and the wall. The illustrated
pressure level is relative to what should have been measured without
any reflections. Note that a maximal distance of 15 mm is a
requirement for wall mounted microphones in many regulations, and
this is the distance when S50 Sound Level Meter is mounted using
the Mounting Wedge, see the previous section. Compensation for the
6 dB increased measurement is not done in the S50, but can be setup
in the post-processing.
Measured sound pressure level as function of the frequency because of total
reflections for three distances between the center of the microphone and the wall
(sinusoidal sound wave).