WIKA Pascal ET User Manual
Page 33
6 Commissioning, operation
WIKA Operating Instruction, Model Pascal ET and Pascal ET/IS 33
GB
Selecting RTD the page for the thermoresistance
set up is shown. Fourteen RTD’s types are
available, plus one RTD User (with coefficient defined by the user).
Figure 18
– Rtd type selection
Once the type of thermoresistance connected to the input IN A is identified, the operator must
indicate the measurement mode: 2 wires, 3 wires or 4 wires measurement; the engineering unit
(°C, °F, K) and related number of decimal.
Measurements of RTD - 4 wires
If possible it is recommended to perform RTD measurement with four wires to
eliminate parasite resistances of the connecting cables. All specifications for
thermoresistance aim for four wires measurement.
RTD USER must be selected when the operator needs to measure a non-standard RTD in
agreement with the following formula:
If T≥ 0 °C R(t)= Ro * (1 + A * t + B * T²)
If T< 0 °C R(t)= Ro * (1 + A * t + B * T² + C (t
– 100) * t³)
Figure 19
– RTD parameters setup