c) At least one of the following tw

c) At least one of the following two options to reduce the spectral mismatch component ofuncertainty shall be utilized:? Perform a spectral mismatch correction. The spectral responsivity of the module shallbe measured according to IEC 60904-8. The spectral response data may originate fromthe same lab that is performing IEC 61 21 5-2:2021 , or from a different lab. The sampleused to obtain the spectral response data may be the test module or may be a referencecell made with the same bill of materials as the test module. The spectral distribution ofthe solar simulator shall then be utilized to correct for spectral mismatch according toIEC 60904-7.? Use a matched reference cell or module. The reference device shall be of the samecell technology as the test module, to match spectral responsivity. There is norequirement on the cell or module size.d) A radiant source: natural sunlight or a solar simulator of class CAA or better in accordancewith IEC 60904-9. F or very large modules, as defined in IEC 61 21 5-1 :2021 , a class CBAsimulator may be used.NOTE 1 Class CBA is defined according to IEC 60904-9: The AM1 .5 spectral match is categorized as C, non-uniformity of irradiance for the module size categorized as B, and temporal stability of irradiance categorizedas A.To achieve a high accuracy of power measurement, the spectral irradiance distribution ofthe solar simulator should cover the whole wavelength range that is spanned by the spectralresponsivity of the PV device under test. See IEC TR 60904-1 4 and IEC 60904-9:2020.e) A suitable mount for supporting the test specimen and the reference device in a planenormal to the radiant beam.NOTE 2 MQT 02 measurement procedures are intended for minimal uncertainty, for example as performed by anaccredited testing laboratory. Lesser requirements, such as use of CAB class simulators, may be appropriate forother applications, such as quality control in the factory. Applications that only require repeatability, such ascomparing module performance before and after an extended stress, may wish to relax spectral mismatch correctionrequirements.4.2.3 ProcedureDetermine the current-voltage characteristic of the module in accordance with IEC 60904-1 ata specific set of irradiance and temperature conditions (a recommended range is a celltemperature between 20 °C and 50 °C and an irradiance between 700 W/m 2 and 1 1 00 W/m 2 )using the apparatus described in 4.2.2. In special circumstances when modules are designedfor operation under a different range of conditions, the current-voltage characteristics can bemeasured using temperature and irradiance levels similar to the expected operating conditions.For linear modules (as defined in IEC 60904-1 0) temperature and irradiance corrections can bemade in accordance with IEC 60891 in order to compare sets of measurements made on thesame module before and after environmental tests. For nonlinear modules (as defined inIEC 60904-1 0) the measurement shall be performed within ±5 % of the specified irradiance andwithin ±2 °C of the specified temperature. However, every effort should be made to ensure thatpeak power measurements are made under similar operating conditions, that is minimize themagnitude of the correction by making all peak power measurements on a particular module atapproximately the same temperature and irradiance.For flexible modules, the maximum power determination shall be measured with the flexiblemodule in the flat position.4.3 Insulation test (MQT 03)4.3.1 PurposeTo determine whether or not the module is sufficiently well insulated between live parts andaccessible parts.