The purpose of this SAE Information Report is to list and explain major equipment, instrumentation, and procedure variables which can affect inter-laboratory differences and repeatability of photometric measurements of various lighting devices listed in SAE Technical Reports. The accuracy guidelines listed in the report are for the purpose of controlling variables that are not a direct function of the lighting device being measured. The control of these individual variables is necessary to control the overall accuracy of photometric measurements. These accuracy guidelines apply to the measurement of the luminous intensities and reflected intensities of devices at the specified geometrically distributed test points and areas. These guidelines do not apply to photometric equipment used to measure license plate lamps.
In response to general comments from the members of the SAE Lighting Committee, along with changes in technology, this document has been rewritten. The changes from the last issued version are as follows:
1. Rewrite of Appendix B removing the table of conversions of Type A goniometer's angles to Type B, as the Type B devices are not generally used in the industry any more. Diagram of both types was kept for reference.
2. Added reference to J575 for voltage measurement requirements.
3. Revised the term referencing the use of Accurate Rated Bulbs from "should" to "shall" to match J575.
4. Reference to "Non-Replaceable Light Sources" was removed, and the "Bulbs" section of J575 was referenced.
5. A general guideline of a base-line laboratory temperature of 23 ºC ( 73 ºF ) was added.
6. The reference for ASTM Report E 308-85 has been updated to the newest revision. Also, the ASTM Report is no longer available in the HS-34 Handbook Section IV, so this reference has been moved.
7. A reference to IESNA Reports about the types and usage of goniometers was added.
8. Fixed reference to J2139 which was incorrectly stating J2039.