Absolute Alignment of the Reference Retroreflectometer at NIST

Published

June 1, 2003

Author(s)

Carl C. Miller

Abstract

The National Cooperative Highway Research Program (NCHRP Project 05-16) awarded The National Institute of Standards and Technology (NIST) a contract to develop a dedicated reference instrument for measuring retroreflective materials, and a calibration program that provides traceability to the relevant national scales maintained by NIST. The most critical aspect of the NIST Reference Retroreflectometer is the absolute alignment of the three components: thesource, the goniometer, and the detector. Presented are the methods for aligning the components and the uncertainty of the four angles defined as the CIE goniometer system. The expanded uncertainty (k=2) for the observation angle, alpha, is 0,00057 ; for the entrance angle components, beta 1 and beta 2, is 0,0090 ; and for the rotation angle, epsilon, is 0,061 .

Proceedings Title

Commission Internationale de L'eclairage | 25th | | CIE

Volume

152

Conference Dates

June 25-July 2, 2003

Conference Title

Publications Commission Internationale De L'Eclairage CIE

Pub Type

Conferences

Keywords

calibration standard, retroreflection, retroreflectometer, uncertainty

Citation

Miller, C. (2003), Absolute Alignment of the Reference Retroreflectometer at NIST, Commission Internationale de L'eclairage | 25th | | CIE (Accessed April 24, 2026)

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