Instruction manual
04/12 ALF
1. Description
The SPL noise level indicator is an accurate, handy
and easy-to-use meter for measuring sound levels. It
can be used to indicate noise levels in schools, in-
cluding pre-school establishments, homes, work-
places etc.
The equipment detects noise by means of a built-in
microphone. The incoming sound signal is first am-
plified and filtered, then its intensity is measured
and the noise level in dB is indicated on the digital
display.
A colour-coded display in the form of a caricatured
face provides an easily seen indication when a spe-
cific pre-defined threshold has been exceeded. A
smiling green-coloured face will change to a frown-
SPL Noise Level Indicator 1012741
ing red face when the noise in the room gets too
loud.
The brightness of the various display elements can be
set individually.
The noise level indicator features an energy-saving
stand-by mode (average consumption below 0.7 mA).
When the display switches to this mode, the noise
level is no longer measured continually. The device
automatically switches to stand-by mode if noise
remains at a minimal level for a lengthy period (about
5 minutes). If the level increases again, the indicator
automatically switches back to measuring mode. It
also enters sleep mode if the level remains under a
set threshold (42 dB) for longer than two minutes. In
this mode, the device checks every two minutes
whether the level has become louder and, if it has, it
goes back to measuring mode. The indicator
1
1 Stand
2 «SET" button
3 Colour-coded display («face")
4 «+/-" configuration button
5 Warning indicator for power
supply
6 Power supply connector (mini-
USB socket)
7 Microphone
8 Digital noise level display