Measurements of Infrared Spectral Directional Emittance at NIST - A Status Update

Published

September 12, 2012

Author(s)

Boris Wilthan, Leonard Hanssen, Sergey Mekhontsev

Abstract

Over the past two decades, the Sensor Science Division at the National Institute of Standards and Technology (NIST) has developed extensive capabilities for the characterization of the infrared optical properties of materials and components. These include the more recent development of infrared spectral emittance (emissivity) measurements by the direct method of radiance comparison to blackbody reference sources over a temperature range of 200 °C to 900 °C over a wavelength range of 2 µm to 20 µm. This paper reports on the recent progress. Initial validation of the measurement methodology was made through comparisons with the indirect method of reflectance measurement on the NIST infrared reference integrating sphere at a limited temperature range up to 200 °C. Subsequently, NIST piloted and participated in an international intercomparison of infrared spectral emittance with the national measurement institutes of France, Germany, Italy and Japan. The overall agreement of the results provides a strong validation of NIST's methodologies and uncertainty budgets. Most recently, to address the current lack of standards for total emittance, measurements are being extended to wavelengths up to 100 µm. Finally, angle-dependent emittance measurements are being implemented, which will also provide sufficient data for the calculation of hemispherical emittance

Proceedings Title

Temperature: Its Measurement and Control in Science and Industry, Vol. 8

Volume

1552

Conference Dates

March 19-23, 2012

Conference Location

Anaheim, CA, US

Conference Title

Ninth International Temperature Symposium

Pub Type

Conferences

Keywords

Emittance, emissivity, infrared, spectral, directional

Citation

Wilthan, B. , Hanssen, L. and Mekhontsev, S. (2012), Measurements of Infrared Spectral Directional Emittance at NIST – A Status Update, Temperature: Its Measurement and Control in Science and Industry, Vol. 8, Anaheim, CA, US (Accessed December 14, 2024)