National Physical Laboratory

Temperature & Humidity Research

Our experienced team provides world-leading research into the development of innovative sensors, standards and measurement solutions.
  • Self-validating thermocouples are designed specifically to allow in-situ validation, where removal of the thermocouple is impractical and the exposed temperature is or can be cycled through a fixed point phase transition. Working prototypes are in use and development of industrially-applicable pieces is ongoing.
  • NPL is making fixed-points based on metal-carbon eutectic alloys that can provide reference points with a certified uncertainty of 0.05% of the ITS-90 temperature. NPL is coordinating a global research programme to introduce these reference standards for better temperature and optical radiation measurements.
  • NPL carries out research into standards, calibration and measurement methods for humidity and related properties.
  • NPL's new technology in thermal metrology has enabled British industrial partners to move forward with ultra-efficient jet engine. Through industrial implementation of a Co-C Fixed Point for Thermocouple Calibration.
  • NPL has facilities for measurement of moisture content in a variety of materials and sample types. Services offered include measurements, research studies, training, consultancies and instrument assessments.
  • Practical Acoustic Thermometry is a novel technique for measuring the temperature, particularly suited to measurements in harsh conditions at high temperatures.
  • NPL is embarking on a project to use primary acoustic gas thermometry to measure thermodynamic temperature in the range from – 40 °C to + 156 °C. This will provide new knowledge about the thermodynamic accuracy of the ITS-90, and in the longer term it will provide NPL with a capability for the direct dissemination of thermodynamic temperature over a wider range.
  • Metal-carbon eutectic alloy fixed-points constructed at NPL provide temperature reference standards up to 2500 °C for radiation thermometry.
  • NPL's research into infrared (IR) thermal imaging camera measurement, its development and application.
  • Metal-carbon eutectic fixed points are bringing about a step change in contact thermometry. Increasing thermocouple calibration availability.