<span style='color:red'>NEW!</span> IEC 60904-2:2015 is available as <a href="http://webstore.iec.ch/webstore/webstore.nsf/Artnum_PK/9999982 918?opendocument">IEC Standards+ 60904-2:2015 which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition. IEC 60904-2:2015 gives requirements for the classification, selection, packaging, marking, calibration and care of photovoltaic reference devices. This standard covers photovoltaic reference devices used to determine the electrical performance of photovoltaic cells, modules and arrays under natural and simulated sunlight. The main technical changes with regard to the previous edition are as follows: - addition of a test procedure in simulated sunlight of subsequent measurement of primary and secondary reference device; - definition of standard test conditions; - reduction of allowed diffuse component for secondary reference cell calibration.