Siemens SITRANS T4200, Operating Instructions Manual

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Functions
9.6 Measured value offset
SITRANS TH200/TH300
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Operating Instructions, 06/2010, A5E00393069-03
9.6 Measured value offset
An offset response on a specific measurement channel can be set in the parameters for
applications in which the process variable to be measured cannot be measured directly at
the measuring point.
9.7 Sensor factor
The sensor factor is used to adapt the characteristic curve when resistance thermometers
are connected in series or parallel and when thermocouples are connected in series. You
must multiply the sensor factor with the basic series of the resistance thermometer or
thermocouple. Values from 0.25 to 10.0 can be set as the scaling factor in resistance
thermometers, while values from 1 to 10 can be set for thermocouples.
Example 1: 3 x Pt500 parallel: Sensor factor= 5/3 = 1.67 (basis is Pt100)
Example 2: 4 x TC serial: Sensor factor = 4 x 1 = 4
9.8 Cold junction compensation with thermocouples
In order to measure the cold junction for thermocouples, you can choose between the
following cold junction compensation versions:
● Internal: in this case, the thermocouple or the compensating line is directly connected to
the transmitter. The cold junction temperature is obtained by an internal Pt100.
● External with fixed value: specify the external cold junction temperature, e.g. of a
thermostat, as a fixed value. The transmitter then compensates according to this constant
cold junction temperature.
● External with Pt100: an external Pt100 measures the cold junction temperature in this
version. You can connect the Pt100 to the transmitter in two-wire or three-wire input. The
cold junction is compensated on the basis of the current temperature of the external
Pt100.