Built-in Data Logger
5.3
Calibrating the Temperature and Relative humidity sensor -METBASIC
Kit
The functioning check of the single Temperature and Relative humidity sensors (METBASIC
KIT), has to be done by comparison with other meteo reference sensors.
The calibration certificate of the meteo sensors should be asked with the purchase order and
is subject to a quotation.
Temperature and humidity sensor have been calibrated from the manufacturer and do not
need any further calibration within a period of two years. After this period the sensors cap
may be controlled using an external thermo-hygrometer and eventually changed and
substituted with a new calibrated device or using new spare parts.
5.4
Calibrating the noise sensor
The noise sensor should be calibrated using a noise
sound generator.
The calibration procedure requires a noise calibrator
with 94/104 dB at 1 KHz. The calibration should be
carried out in a silent ambient to avoid external
interferences.
The calibration can be performed in two different
ways.
1.
Preliminary calibration
2.
Total Calibration
The preliminary calibration
can be performed only to verify the noise meter functionality.
It is necessary to open the jumper J1 and give a reference voltage on Pin 2 of the same
jumper.
The reference voltage should be 100 mV that correspond to 100 dB in the 60-120 scale.
You can measure the input voltage on TP3.
When the 100 mA have been sent, it should be measured the voltage on TP1, that should
correspond to -120,0 mV. To obtain such value it is necessary to turn the Zero Trimmer T3.
When this first calibration point has been adjusted, it remains to calibrate the output level. If
you have the 4-20 mA output you have to set 14,667 mA adjusting the trimmer T2.
The total calibration
needs a noise pressure generator. You have to put the noise meter
inside the acoustic generator, but not completely closed. Unplug the microphone from the
black PVC block and maintaining it connected to the circuit place it inside the calibrator. The
two noise meters have been calibrated using a CIRRUS CRL 511E calibrator, that has got two
noise levels at 94 and 104 dB (1000 Hz).
ORION S.r.l.
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