A National Measurement System for Radiometry, Photometry, and Pyrometry Based upon Absolute Detectors

Albert C. Parr
Optical Technology Division, Physics Laboratory
National Institute of Standards and Technology, Gaithersburg, MD   USA   20899-8440

Abstract: Advancements in the performance and ease of use of absolute photodetectors based upon electrical substitution principals offers the possibility of a simplified and more accurate way to transfer the fundamental radiometric, photometric, and pyrometric units from NIST to the U.S. technical establishment. The history of electrical substitution radiometers at NIST is briefly reviewed and the implementation of the latest generation absolute cryogenic radiometer is discussed. Procedures to maintain fundamental units based upon a detector approach are reviewed in a general way with references to the technical literature for detailed discussion. It is proposed that NIST customers consider adopting the suggestions made in this technical note to simplify and improve their optical radiation based calibrations.

CONTENTS  (Cover Page)

1. Introduction
2. Electrical Substitution Radiometry
3. Detector Spectral Comparators
4. Filter Detector Systems and Use
   1. Photometry and Colorimetry
   2. Spectral Radiometry
   3. Pyrometry
5. Conclusions and Suggestions
   References