Electrical Mounting - WIKA A2G-60 Betriebsanleitung

5. Commissioning, operation
Installation with a thermowell or compression fitting is necessary when
used in liquid media. For better heat transfer from the thermowell to the
temperature sensor, thermal compound should be used.
EN

5.2 Electrical mounting

Heat generation due to electrical dissipation loss
Temperature probes with electronic components always have an electrical
dissipation loss that affects the temperature measurement of the ambient
air. The dissipation loss occurring in active temperature probes increases
with rising operating voltage. This dissipation loss must be taken into
account in the temperature measurement. With a fixed operating voltage
(±0.2 V) this is usually done by adding or subtracting a constant offset
value. Since the transmitters used work with a variable operating voltage,
only one operating voltage can be taken into account for production
engineering reasons. The 0 ... 10 V/4 ... 20 mA transmitters are set, as
standard, at an operating voltage of 24 V, i.e. at this voltage the expected
measured error of the output signal is lowest. At other operating voltages,
the offset error increases due to the changed dissipation loss of the probe
electronics. If recalibration is necessary directly at the probe during later
operation, this is possible using the trim pot on the probe board (for probes
with BUS interface, via a corresponding software variable).
If there are draughts, the dissipation loss at the probe is better
dissipated. This causes temporary deviations in the temperature
measurement.
14 WIKA operating instructions model A2G-60