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4.7
Periodical testing
Before and after each measurement, the S51 Sound Level Meter
shall be tested with an Acoustic calibrator to check if the calibration
still is within the stated limit. Use for example the acoustic calibrator
SV 30A
from Svantek (1 kHz). Any of the S51 standards can be used
here.
Instruction:
1. Take down the S51, if it is mounted against a wall.
2. Remove the windscreen and bird spikes from the S51 unit.
3. Gently attach the Acoustic calibrator on the microphone.
4. Set Upper threshold to OFF to prevent unnecessary trigging of the
system during the test.
5. Activate REG ON.
6. Activate the Acoustic calibrator, select 94 dB.
7. Wait about 10 seconds, then use “Live” in the INFRA Datalogger
(see instruction below) to read the current sound pressure level (the
first value is not valid due to start-up effects). Press “live” several
times to be sure that the value is stable. The displayed value shall not
differ more than ±1.0 dBA from the selected level of the acoustic
calibrator. If it differs more, investigate the source of deviation.
Note! High background noise levels affect the measurement.
How to read “Live” value (Reg On must be active) :
1. If nothing is displayed on the INFRA Datalogger, press the left
button (F1). When the display lights up, press the right button (F2),
“Continue”.
2. Simultaneously press the two middle buttons (▲ and ▼) three
times until “LIVE” is displayed.
3. Every time you press F2, the “Live-value” is updated.
4. If you have several nodes connected to your Datalogger, press ▲
or ▼ until the “Live-value” of your S51 is displayed.
Read more about the Live functionality in the Infra Master Manual.
