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Reflections
The sound level meter operator and the sound level meter itself can interfere
with the measurements being made, reflecting the noise signal. The instrument
case for the Sonus range of sound level meters has therefore been designed to
minimize reflections whilst also being of rugged construction.
To minimize reflections from the operator hold the sound level meter at arm’s
length, mount the sound meter on a suitable tripod (adapter required) or use a
microphone extension cable (if applicable).
Time Weighting
The time weighting is a time constant that modifies the response of the
instrument to fluctuating noise levels. Without time weighting the meter display
would fluctuate following the measured noise level and would be unreadable, the
selected time weighting therefore softens these fluctuations over the time
periods described below and in doing so the meter has a more readable display.
Depending on your instrument type (see
Technical Specifications
for further
details), the following standardised time weightings are available: -
Slow Weighting
Shows a slow rise in the Sound Pressure Level even for a sharp rise in the noise
level, likewise a rapid reduction in noise will be shown as a slow decrease in
Sound Pressure Level. The rise and fall times applied for Slow Weighting are 1
second.
Fast Weighting
The most commonly used time weighting which follows the noise level closer
than slow weighting by displaying a fast rise and fall in the Sound Pressure Level.
The rise and fall times applied for Fast Weighting are 125m Seconds.
Impulse Weighting – (Models GA116E, GA116L & GA216L Only)
Allows your meter to show rapid rises in the noise level but has a very slow
decay. The rise and fall times for Impulse Weighting are 35m Seconds and 1.5
Seconds respectively.
