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. At this time we would like to reaffirm J1330 in its current revision. A full rewrite is being prepared by the task force at this time to include many new technologies and measurement techniques to improve the measurement accuracy of photometric laboratories. Many of the topics are going to be discussed with general terms, and also specific examples of various industries, so that more than one industry can use this standard. This includes at this time both the automotive and aerospace aircraft lighting industries. Some changes included will be: a Measurement of PWM (Pulse Width Modulated) and other modulated sources. b Measurement of Chromaticity, UV Content, Red (and other color) Content, retro-reflex color. c Measurement of Low Light Level sources, including Low-light Visibility. d Added to “Related Publications” SAE J2382 as a method of high-speed photometric measurement that references this document. e Measurement of Luminance, including License Plate Lamps and other luminance measurements. f Measurement of Flashing Light sources. g Measurement of Total Luminous Flux using an Integrating Sphere. h Added references to IESNA documents