The Development and Characterization of an Absolute Pyrometer Calibrated for Radiance Responsivity

Published

September 1, 2003

Author(s)

David W. Allen, Robert D. Saunders, Bettye C. Johnson, Charles E. Gibson, Howard W. Yoon

Abstract

The International Temperature Scale of 1990 (ITS-90), for temperatures above the freezing temperature of silver, is defined with pyrometers which rely upon spectral radiance ratios to one of the silver, gold or copper freezing temperature blackbodies and the use of the Planck radiance law. However, due to the use of spectral radiance ratios, the temperature uncertainties of ITS-90 increase as the square of the temperature ratios. Such increases in the temperature uncertainties can be reduced by using absolute radiometry traceable to cryogenic radiometers, and the resulting temperature uncertainties can be smaller than those measured using the ITS-90 techniques. We describe the development and the characterization of an absolute pyrometer (AP1) constructed at NIST and calibrated using absolute radiance responsivity. The calibrations are performed with the pyrometer as a single unit and thus separate measurements of the lens transmittance and the spectral responsivities of the filters and detectors are not necessary. The temperature measurement capabilities of the AP1 are shown using the melt and freeze cycle of the gold-point blackbody.

Proceedings Title

Temperature, International Symposium | Eighth | Temperature: Its Measurement and Control in Science and Industry; Volume Seven | AIP

Volume

684

Issue

No. 1

Conference Dates

October 21-24, 2002

Conference Title

AIP Conference Proceedings

Pub Type

Conferences

Keywords

absolute radiometry, gold freezing temperature, radiance responsivity, thermodynamic temperature

Citation

Allen, D. , Saunders, R. , Johnson, B. , Gibson, C. and Yoon, H. (2003), The Development and Characterization of an Absolute Pyrometer Calibrated for Radiance Responsivity, Temperature, International Symposium | Eighth | Temperature: Its Measurement and Control in Science and Industry; Volume Seven | AIP (Accessed September 13, 2024)