Thermometers with switch contacts

Display and monitor limit values

Wherever the process temperature has to be indicated locally and, at the same time, limit values must be monitored, thermometers with switch contacts find their application. The switch contacts make or break the circuit dependent upon the pointer position of the indicating measuring instrument. If the reading is significantly above or below a set value, they trigger an alarm, hence also the term “alarm contact”. The instruments are also suitable for starting, stopping or switching processes.

What are suitable materials for thermowells and protection tubes for negative temperatures?

The first choice for high-temperature applications should always be stainless steel, such as 1.4404 (Approval per AD2000 W10 down to -270 °C) or 316L. Carbon steels should be considered carefully in detail, through the effect of the drop-off effect.

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