Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

A 2.4mm Coaxial Power Standard at NIST



Thomas P. Crowley, Fred R. Clague


A microcalorimeter and bolometer transfer standard are used as a national standard for microwave power from 50 MHz to 50 GHz. the microcalorimeter is used to determine the efficiency of the bolometric transfer standards and is similar to an existing Type N coaxial microcalorimeter at NIST. The transfer standards are dc substitution power detectors with two resistors on a small integrated circuit that are tightly thermally coupled. One resistor terminates the coaxial input and dissipates the RF power while the other resistor dissipates DC power. The first resistor is temperature insensitive and approximately 50W while the second resistor (which has a positive temperature coefficient) is about 1000W and acts as the bolometer element. A power supply maintains the bolometer element at constant resistance. Typical calorimeter data is shown and future plans for development will be briefly discussed.
Conference Dates
November 6-8, 2001
Conference Location
Harrogate, 1, UK
Conference Title
2001 British Electromagnetics Conference


2.4 mm coaxial, bolometer, calorimetry, metrology, microcalorimeter, microwave


Crowley, T. and Clague, F. (2001), A 2.4mm Coaxial Power Standard at NIST, 2001 British Electromagnetics Conference, Harrogate, 1, UK (Accessed July 25, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created October 31, 2001, Updated October 12, 2021