VEGA FIBERTRAC 31 4 … 20 mA_HART - four-wire With SIL qualification - Manual (Page 36)

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7 Set up with the display and adjustment module
FIBERTRAC 31 • 4 … 20 mA/HART - four-wire
43386-EN-131119
Select "Linearization - New" to enter the first point.
Select "Determine count rate" to enter the first point.
The determination of the actual count rate lasts 2 minutes. After the
count rate has been determined, you can accept the value (ct/s).
The count rate is stated in ct/s. This is the number of counts per sec-
ond, i.e. the measured radioactive radiation dose actually reaching
the sensor.
Enter now the corresponding level (m).
By doing so, you assign a respective level to the actual count rate.
Accept the value pair with "OK".
Depending if you have started with full or empty vessel, you have to
continue emptying or filling the vessel.
Also carry out such a linearization with several different filling heights
if you have a linear vessel.
By doing so, you can influence the measurement reliability of the
sensor. The more linearization points you enter and the bigger the
difference between the first and the last linearization point, the more
reliable the measurement will be.
If you have a non-linear vessel (e.g. spherical tank), you have to carry
out this adjustment with as many points as possible.
A maximum of 32 linearisation points is possible.
Note:
If you cannot fill the vessel during the adjustment procedure to at least
60 % of the max. level, it is possible to carry out the full adjustment
by switching off the radiation. The switched-off radiation simulates a
100 % filling.