Knowledge

The most frequently measured process variable at the moment is temperature. Previous studies indicate that of all recorded process data, approximately 60% is temperature related.

Temperature measurement for industrial applications is accomplished with thermocouples and resistance temperature detectors. Thermocouple and resistance thermometry both sense temperature using very low voltage signals.

Thermocouples generate a very low voltage signal (EMF) that is temperature dependent and can be used to measure a temperature at a distance and use the signal to control and or record the process data.

Thermocouples come in various “calibrations,” which refer to the specific combinations of metals used. These calibrations are standardized to ensure consistent EMF generation at given temperatures.