CEMB USA TR-NC8 ATEX - Manual (Page 4)

4
TRANSMITTER SETTING
The TR-NC/8 instrument is normally supplied complete with the sensor already set.
Replacement of the sensors does not involve recalibration of the transmitter.
After arranging the sensor with the nominal air gap indicted above (1.50 mm) and
connecting it to the transmitter, proceed to adjust the setting of the sensor and
transmitter as follows:
- make the transmitter power connection on the terminals marked with POWER.
- connect a voltmeter across the transmitter terminals marked with GAP.
- make small movements of the sensor until reading a voltage of 5 Vdc on the voltmeter;
then lock the sensor in this position.
For VIBRATION measurements: in the absence of vibrations, current output is 4 mA ± 0.2
mA. It is possible to readjust the rest current by adjusting the trimmer marked by the
wording “4 mA” located at the bottom of the transmitter; it is advisable to perform
such operation after waiting for at least 15 minutes from switching on the transmitter.
For DISPLACEMENT measurements: in the “zero displacement” position (mid point of the
measurement range) output current is 12 mA ± 0.2 mA.
REMARKS REGARDING CORRECT POSITIONING OF TRANSMITTERS TR-NC/8
1) Never, under any circumstances, modify the sensor / transmitter cable length: this
would cause a measuring error.
2) The end part of the sensor must lie at a distance from metal materials different
from the one involved in measuring the distance: at least twice the max. amplitude
of measurement (see application drawing).
3) When mounting the sensor, a reference cone should be prepared at 90° vertex from
the sensor tip. No metallic material must be introduced in the cone apart from the
surface to be measured.
NOTES CONCERNING CERTIFICATION:
1) The use of ATEX certified transmitters is not allowed for different hazardous
conditions or for those exceeding the data specified on the nameplate affixed to
the transmitter.
2) The transmitter does not require maintenance. Any work regarding performance checks
or repair should only be carried out in a laboratory duly authorized by CEMB SpA.