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.

Realization of an Infrared Spectral Radiant Power Response Scale on a Cryogenic Bolometer



Alan L. Migdall, George P. Eppeldauer


The National Institute of Standards and Technology [NIST] has developed an IR radiant power response scale for the spectral range from 2 micro υ to 20 micro υ. The scale has been realized on a cryogenic bolometer. The response of this bolometer has been determined by multiple ties to a primary standard, the NIST High Accuracy Cryogenic Radiometer [HACR]. These transfers were made using three intermediate detectors over three different spectral regions. In addition, an independent method was used to determine the relative response of the bolometer over the entire spectral range. An IR spectral response scale over the entire 2 micro υ to 20 micro υ range was determined from these measurements, with the interlocking nature of the multiple independent measurements providing improved confidence and reduced uncertainties. The overall scale combined standard uncertainty for the entire spectral range of 2 micro υ to 20 micro υ is of the order of 0.25%, with the typical combined standard uncertainty of an individual measurement made with bolometer being {difference} 0.8%.


bolometer, calibration, cryogenic radiometer, infrared, infrared detectors, optical measurement, optical power, scale


Migdall, A. and Eppeldauer, G. (1998), Realization of an Infrared Spectral Radiant Power Response Scale on a Cryogenic Bolometer, Metrologia, [online], (Accessed June 17, 2024)


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

Created January 1, 1998, Updated February 17, 2017