Rh eo n i k M esst ech n i k
RE V . L O ct o b er 2014
.
RHEONIK Coriolis Flowmeter
Operation Manual RHE 07, 08, 11
Page
32
No t e f o r HT S en so rs :
High temperature sensors RHM HT need special grounding.
Check ground wiring according to diagram and the informations in section 1.3.
Insulation resistance earth to ground should be much higher then 1MOhm
*
under
good operation conditions.
*
The relatively low resistance is caused by the hygroscopic characteristics of the used
ceramic construction materials and varies with the moisture inside the sensor.
A resistance of i.e. only a few hundred KOhm shows a sensor that is completely moist.
That leads to failures or non-function (please contact the person responsible at your local
representative, to solve this problem).
5.2. TEMPERATURE CALIBRATION
Temperature measurement is already factory calibrated. Normally a new temperature
setup or new recalibration is not necessary. The PT100 is connected by 3 wires, so that
the measurement is just influenced by one wire resistance.
For extreme long cable length there is a software
Adjust
Funktion for compensating the
wire resistance.
This can be done in the
Adjust Menu
. For this the actual temperature must be well known,
or a resistor simulating a certain temperature has to be connected instead of the meter
PT100.
Enter the correct temperature by entering a positive or negative offset value and press
the adjust push-button. After this procedure the temperature reading will be ok.
