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Temperature measurements

Self-validating thermocouples

Improve long-term reliability without removal for re-calibration

NPL has pioneered practical techniques to validate thermocouple readings in situ, or when the removal of a thermocouple for calibration is impossible or impractical.  There are two methods and in both cases, the cell contains an ingot of metal (or eutectic metal-carbon alloy) which melts/freezes at a known temperature, chosen to be of particular relevance to the operational process in which the thermocouple is used. When the thermal environment of the thermocouple passes through this particular temperature, a hesitation (or plateau) in the thermocouple reading is observed. This enables a check to be made on the thermocouple performance.

Miniature fixed-point cells

This technology is a miniaturised version of the conventional calibration fixed-point cells. The new cell is a 3 cm x 1 cm cylinder which can be placed around the measuring junction of a 3 mm outer diameter thermocouple.

Integrated self-validation (inseva) design 

This technology has a different, much smaller, design. The outer diameter is just 4 mm – enabling it to fit inside the sheath of a typical 7 mm outer diameter (alumina insulated) thermocouple.

This technology is licenced to CCPI Europe, and we continue to support the development of this technology, in partnership with CCPI Europe

Don’t see what you are looking for? Our diverse skill set enables us to provide bespoke solutions. Please contact us to discuss your requirements.

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