This specification provides means for classifying solar simulators intended for indoor testing of photovoltaic devices (solar cells or modules), according to their spectral match to a reference spectral irradiance, non-uniformity of spatial irradiance, and temporal instability of irradiance. Testing of photovoltaic devices may require the use of solar simulators. Test Methods that require specific classification of simulators as defined in this specification include Test Methods E 948, E 1036, and E 1362. This standard is applicable to both pulsed and steady state simulators and includes recommended test requirements used for classifying such simulators. A solar simulator usually consists of three major components: (1) light source(s) and associated power supply; (2) any optics and filters required to modify the output beam to meet the classification requirements in Section ; and (3) the necessary controls to operate the simulator, adjust irradiance, etc. A light source that does not meet all of the defined requirements for classification presented in this document may not be referred to as a solar simulator. Spectral irradiance classifications are provided for Air Mass direct and global (as defined in Tables G 173), or Air Mass 0 (AM0, as defined in Standard E 490). The classification of a solar simulator is based on the size of the test plane; simulators with smaller test plane areas have tighter specifications for non-uniformity of spatial irradiance. The data acquisition system may affect the ability to synchronize electrical measurements with variations in irradiance and therefore may be included in this specification. In all cases, the manufacturer must specify with the temporal instability classification: (1) how the classification was determined; and (2) the conditions under which the classification was determined. The classification of a solar simulator does not provide any information about electrical measurement errors that are related to photovoltaic performance measurements obtained with a classified solar simulator. Such errors are dependent on the actual instrumentation and procedures used. The following precautionary caveat pertains only to the hazards portion, Section , of this specification. 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 requirements prior to use.