NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.

Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.

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.

PUBLICATIONS

Preliminary characterization study of a gold-coated concentrator for hemispherical longwave irradiance measurements

Published

Author(s)

Jinan Zeng, Leonard M. Hanssen, Ibrahim Reda, Jonathan Scheuch

Abstract

We report the preliminary characterization results of a gold-coated concentrator used for longwave irradiance measurements[1]. Throughput measurements of the concentrator are conducted at 1.562 μm and 10.15 μm using two different approaches, one is referred to a transmittance measurement using the Complete Hemispherical Infrared Laser-based Reflectometer (CHILR)[2] of NIST, and the other one is a direct throughput measurement using an existing thermopile detector for longwave irradiance measurement. For the transmittance measurement using CHILR, two diffuse gold references are selected to generate a Lambertian source by shining a laser on them. Spatial variations of transmittance of the concentrator are also investigated by scanning the laser beam across the opening area of it with a gold diffuser. For the direct throughput measurement, a small diffuse gold integrating sphere of 25.4 mm in diameter is utilized to produce an ideal diffuse source. The thermopile detector measures the radiation passing through the concentrator from the small integrating sphere. The incoming irradiance is determined from signal outputs of the thermopile detector and ambient temperature changes. Comparing with the results from the two approaches, a consistent throughput of the concentrator is obtained about 91 % to 92 %. The error sources and uncertainty in the two measurements are also discussed.
Proceedings Title
SPIE Optics + Photonics
Conference Dates
August 1-5, 2010
Conference Location
San Diego, CA
Pub Type
Conferences

Keywords

BRDF, Complete Hemispherical Infrared Laser-based Reflectometer, Concentrator, diffuse gold reference, integrating sphere

Citation

Zeng, J. , Hanssen, L. , Reda, I. and Scheuch, J. (2010), Preliminary characterization study of a gold-coated concentrator for hemispherical longwave irradiance measurements, SPIE Optics + Photonics, San Diego, CA (Accessed October 13, 2025)

Issues

If you have any questions about this publication or are having problems accessing it, please contact [email protected].

Created November 15, 2010, Updated February 19, 2017
Was this page helpful?