Thermometry

The NIST Temperature and Humidity 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...

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...

Thermometry for semiconductor processing - Thermal processing of semiconductors is a critical, capital intensive step in achieving high yields and profitability in the manufacturing of electronic chips. Many techniques have been developed...