title: National Institute of Standards and Technology high-accuracy cryogenic radiometer.
abstract: A high-accuracy cryogenic radiometer has been developed at the National Institute of Standards and Technology to serve as a primary standard for optical power measurements. This instrument is an electrical-substitution radiometer that can be operated at cryogenic temperatures to achieve a relative standard uncertainty of 0.021% at an optical power level of 0.8 mW. The construction and operation of the high-accuracy cryogenic radiometer and the uncertainties in optical power measurements are detailed.
authors.forename: T R
authors.initials: TR
authors.lastname: Gentile
authors.forename: J M
authors.initials: JM
authors.lastname: Houston
authors.forename: J E
authors.initials: JE
authors.lastname: Hardis
authors.forename: C L
authors.initials: CL
authors.lastname: Cromer
authors.forename: A C
authors.initials: AC
authors.lastname: Parr