Standards for Non-Uniformity, Temporal Instability of Irradiance, Total Irradiance within 300 Field of View, and how closely the system's radiation spectral distribution matches sun's radiation have been established by various organizations. In the USA, American Society for Test and Measurement (ASTM) has established such standards for Solar Simulators. Standard reference # E927 specifies three different classes of Solar Simulators. These classes and ASTM E927 equirements are as follows:

* Note: These values represent the ratio of actual radiation for each interval to the ASTM E927 specified radiation for each interval as a percentage of the ASTM E927 specified total radiation.

In addition, an intensity of 1,000 W/cm2 is defined as " ONE SUN " for a system with a filter of Air Mass 1.5. Solar Simulators with light output of a multiple of suns are also available.

European and Japanese standards are similar to the ASTM standards for classes of Solar Simulators.