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Calibration / Adjustment
Product Calibration
Product Calibration
When the sensor cannot be removed, e.g. for sterility reasons (for biotechnical
processes), its cell factor can be determined with “sampling”.
To do so, the currently measured process value is stored by the Protos.
Immediately afterwards, you take a sample from the process. The sample value
should be measured at process conditions (same temperature!). The deter-
mined value is entered in the measuring system. From the difference between
process value and sample value, the Protos calculates the cell factor of the
conductivity sensor.
During calibration the module is in HOLD mode.
Current outputs and relay contacts of the module behave as configured
(Module BASE).
Product Calibration Without TC Correction
Take a sample from the process. Measure its value at the temperature at which
the sample has been taken (“Sample temp“, see display). To do so, it may be
necessary to thermostat the sample correspondingly in the lab.
Temperature compensation must be turned off at the comparison meters
(TC = 0 %/K).
Product Calibration With TC Correction T
ref
= 25 °C
Take a sample from the process. When measuring in the lab (TC linear), be sure
that the same values are set for reference temperature and temperature coef-
ficient in the comparison meter and in the Protos. Furthermore, the measuring
temperature should correspond to the sample temperature (see display).
Transport the sample in an insulated container (Dewar).
NOTICE!
Product calibration can only be performed if the process medium is stable.
That means, for example, that there are no chemical reactions which have an
effect on the process conductivity. At higher temperatures, the sample values
can also be invalidated due to evaporation.
Product calibration
