1.1 Scope This standard includes general requirements for photometric testing of most types of lamps. This standard specifies the standard conditions for photometric testing and recommends testing procedures to ensure sufficient accuracy and reproducibility of the determined photometric characteristics of lamps and their presentation reports. These regulations provide a basis for unified national standards and provide guidance for the testing of photometric laboratories and the expression of lamp performance data. For lamps with actual testing conditions different from standard testing conditions, the standard provides measurement requirements for correction factors. For laboratory personnel and engineers, a detailed description of photometric measurement methods is the most important, and it is equally important for data users. The appropriate interpretation of data usually relies on a thorough understanding of the measurement process involved, and this standard also provides users with an understanding of photometric measurement procedures and expressed data. When there is a need for special recommendations related to measurement and data expression requirements for special types of lighting fixtures designed for extremely professional facilities, such general standards cannot cover their characteristics and should be met with many supplementary standards. These supplementary standards will be referenced in appropriate chapters of this standard and special requirements and measurement conditions will be defined when necessary. For lamps without specific standard coverage, the most suitable standard and the requirements of this general standard can be used to guide the actual measurement procedure. 1.2 Photometric characteristics Photometric characteristics can be divided into measured characteristics, which are directly measured using experimental equipment, and derived characteristics, which are calculated from measurement data. The derived characteristics are closer to the relevant lighting applications. This standard mainly involves the measured photometric characteristics. The 2 terms only contain directly related definitions. Some terms listed in this standard may appear under different names (given in square brackets) in other standards. Other relevant definitions can be found in CIE/IEC17.4-1987 [1]. 2.1 Terminology of Luminaire 2.1.1 Luminaire A device that can distribute, emit, or transform light from one or more light sources, and includes all necessary components for supporting, fixing, and protecting the light source (excluding the light source itself), as well as necessary circuit auxiliary devices and devices for connecting them to the power supply. 2.1.2 (Lighting fixtures) Design attitude (of luminaire) [also tilt normal in ap application] The working attitude of the lighting fixture design (determined by referring to the manufacturer's instructions or commonly used methods). 2.1.3 (Lamp) Measurement attitude (of luminaire) [also tilt normal measurement] The attitude of the lamp when tested. Note: If not specified, adopt a posture consistent with the design