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The NIST Thermodynamic Metrology Group maintains and develops national standards of temperature (in the range 0.65 K to 1235 K), and supports calibration of all types of contact thermometers up to 2370 K.


Our goals include:

  • Supporting the equivalence of temperature measurements in the U.S. and abroad, through calibrations, standardized methods, and comparisons and proficiency testing
  • Providing customers access to the highest quality of temperature reference standards, through calibrations, reference data, and standard reference materials
  • Improving the recipe for the International Temperature Scale, by research on temperature standards, acoustic thermometry, and Johnson noise thermometry
  • Supporting accurate measurements of temperature for various applications, such as semiconductor processing.

Acoustic thermometry - By measuring the speed of sound in argon gas, we have determined thermodynamic temperature with unprecedented accuracy in the range 0 °C to 552 °C. Our results are used to improve the...

Johnson noise thermometry - Johnson noise thermometry (JNT) is a primary temperature measurement technique based on the fundamental properties of thermal fluctuations in conductors. We measure these fluctuations with respect...

Photonic thermometry - For nearly a century, accurate temperature measurements in the manufacturing and bio-medically relevant range of –189.3442 ˚C to 961.78 ˚C have been made using electrical measurements...

Promoting alternatives to mercury thermometers - Mercury-filled thermometers have historically served numerous industries as reliable temperature standards. Increased regulation and the high cost of cleaning up mercury spills have encouraged the...

Radiation thermometry - Calibration standards for radiation thermometry are disseminated in the form of radiation thermometers, tungsten strip lamps and blackbodies. These disseminated standards are made traceable to the...

Created October 6, 2011, Updated July 18, 2017