Pt100 Platinum Resistance Thermometers from Peak Sensors

Resistance thermometers are slowly replacing thermocouples in many lower temperature industrial applications (below 600°C). Resistance thermometers come in a number of construction forms and offer greater stability, accuracy and repeatability. The resistance tends to be almost linear with temperature. A small power source is required.

No special extension cables or cold junction compensations are required The resistance of a conductor is related to its temperature. Platinum is usually used due to its stability with temperature. The Platinum detecting wire needs to be kept free of contamination to remain stable. A Platinum wire or film is created and supported on a former in such a way that it gets minimal differential expansion or other strains from its former, yet is reasonably resistant to vibration.

Commercial platinum grades are produced which exhibit a change of resistance of 0.385 Ohms/°C (European Fundamental Interval) The sensor is usually made to have 100 Ohms at 0 °C. This is defined in BS EN 60751:1996. The American Fundamental Interval is 0.392 Ohms/°C.