Thyracont SP363MV, Руководство по эксплуатации

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4 Operation
4.1 General
Measurement Principle
VCC200 vacuum transducers are equipped with an internal capacitance ceramic-
diaphragm sensor.
On the back of a thin sensor diaphragm an electrode structure is applied, opposite
to which a second, rigid electrode is located, the two electrodes forming a capaci-
tor. Under the influence of pressure the thin diaphragm of the sensor is bent. The
resulting change in capacity is a measure for the applied pressure.
Output Signal
The output signal 4.0 - 20 mA of your VCC200 has a linear dependence on pressu-
re over the whole measurement range 0.1 - 200 mbar. Conversion of output signal
and pressure is done according to the following formula:
I
out
(mA) = 0.08 x p(mbar) + 4.0
p(mbar) = (I
out
(mA) - 4.0) x 12.5
Warm-Up Time
The signal output is available approx. 2 s after the unit is switched on. To take
advantage of the maximum accuracy of the unit it is appropriate to allow for a
stabilization time of 5 minutes, especially when extreme pressure changes have
occurred.
Accuracy
The unit is adjusted ex works in upright position and at 24 VDC voltage supply.
Through contamination, ageing, extreme climatic conditions or different mounting
orientation the need for readjustment may arise.
VCC200-4-20 mA-201126