NIST logo
Bookmark and Share



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...

End Date:


Lead Organizational Unit:


Gregory Strouse, Program Leader
301-975-4803 Telephone
301-548-0206 Facsimile

100 Bureau Drive, M/S 8363
Gaithersburg, MD 20899-8363