Battery Test; Performing Measurements; Filter Selection Switch; Damping Selection Switch - Conrad 10 06 09 Bedienungsanleitung

Inserting the battery with its polarities reversed will doubtless
result in the destruction of the measuring instrument.

6. Battery test

Set the On/Off rotary switch (3) to the "Batt" position. For a
good battery, the pointer deflection must reach into the red
"Batt-Test" area of the analogue indicator (5). If this is not the
case, the battery must be replaced as described under point 5,
otherwise perfect operation of the measuring instrument is no
longer guaranteed.

7. Performing measurements

7.1 Filter selection switch

The weighting filter is selected using the filter selection switch
(4). In switch position "A" the frequency response of the Sound
Level Meter matches the characteristics of the human ear, conse-
quently environmental noise (vehicles, machines etc.) is general-
ly measured in dB(A) units.
Switch position "C" is normally reserved for measurements of
acoustic sound signals and sound emitted by bodies (loud-
speakers, etc.).
The frequency response of the filter can be obtained from the
following illustration.
8
Sound in dB
+10
DB (C) Filter
0
- 10
DB (A) Filter
- 20
- 30
DB (C) Filter
0°
90°
- 40
- 50
20 20 100 200

7.2 Damping selection switch

The damping of the pointer deflection can be set to one of two
settings using the "Response" selection switch (2).
If the sound source to be measured is transmitting sound waves
only briefly, or if the maximum volume is to be measured, set the
damping selection switch (2) to "FAST".
If the mean volume of a sound source is to be measured, set the
selection switch (2) to "SLOW".

7.3 Attenuation selection switch

At the start of every measurement, set the attenuation selection
switch (3) to the highest attenuation value "120" and reduce the
attenuation value until a pointer deflection results.
The dB value of the sound source being measured is derived as
follows:
Randon Inciderce refpouse
=
free field refpuse characteris tic at 0 Degrees
=
grazins incipence refpouse (90 Degrees)
=
500 1k 2 5 10
Frequency in Hz
20
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