Temperature Carry-Over From The Process - WIKA RTD Manual De Instrucciones

5. Commissioning, operation

5.4 Temperature carry-over from the process

A heat reflux from the process that exceeds the operating temperature of the transmitter
(digital display) or case is not permitted and must be prevented by installing suitable heat
insulation or a respectively long neck tube.
EN
Increasing the distance of the connection components to hot surfaces
The neck length (N) is defined as the distance between the lower edge of the connection
head or case and the heat-emitting surface. The expected temperature at the lower edge
of the connection head or case should be a maximum of 80 °C. The conditions for built-in
transmitters or displays must be considered, and if needed, the neck length should be
increased.
parallel thread
To help select the minimum neck length, the following standard values have been
determined.
Maximum medium temperature
100 °C
135 °C
200 °C
> 200 °C ≤ 450 °C
For thermometers fitted with a connecting cable, the temperature at the interface with the
connecting cable is restricted. The maximum is 150 °C. To ensure that the permissible
temperature is not exceeded, the dimension X must be selected accordingly.
16
tapered thread
Recommendation for
dimension N
-
20 mm
50 mm
100 mm
WIKA operating instructions RTD and TC
Recommendation for
dimension X
-
20 mm
50 mm
100 mm