Ultra-low uncertainty calibration and exceptional drift performance
NPL currently offers UKAS (ISO 17025) calibrations up to 1500 °C employing metal-carbon eutectic fixed points. The calibration uncertainty can be as low as ±0.2 °C over the range 0 °C to 1100 °C, rising to ±0.55 °C at 1330 °C, and ±0.72 °C at 1500 °C.
Our platinum-palladium thermocouples (Pt/Pd) thermocouples, based on extensive research and development, offer ultra-low uncertainties and exceptional drift performance. The types of temperature references used include:
ITS-90 fixed points
These are the reference temperature artefacts, as specified in the ITS-90, for the practical realisation of the temperature scale. At NPL, the Zn (420 °C), Ag (962 °C) and Cu (1085 °C) fixed points are used for UKAS accredited thermocouple calibrations.
High temperature fixed-points
These artefacts provide reference temperatures for contact thermometry, above those specified in the ITS-90. They are made from a eutectic alloy of metal and carbon. At NPL, the Co-C (1324 °C) and Pd-C (1492 °C) fixed points are used for UKAS accredited thermocouple calibrations.