1.1 This practice prescribes the instrumental measurement requirements, calibration procedures, and physical standards needed for precise spectroradiometric data for characterizing the color and luminance of radiant sources. 1.2 This practice lists the parameters that must be specified when spectroradiometric measurements are required in specific methods, practices, or specifications. 1.3 This practice describes the unique calculation procedures required to determine basic colorimetric data of luminous sources. 1.4 This practice is general in scope rather than specific as to instrument, or object, or material. 1.5 The values stated in SI units are to be regarded as the standard. 1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.