Add: This part of IEC 60904 describes the preferred method for determining the equivalent cell temperature (ECT) of PV devices (cells, modules and arrays of one type of module), for the purposes of comparing their thermal characteristics, determining NOCT (nominal operating cell temperature) or alternatively NMOT (nominal module operating temperature), and translating measured I-V characteristics to other temperatures. NOTE Application of the method to NMOT measurements may be limited by the actual electronic load used to enable MPP tracking and Voc measurements, possibly requiring deviations from the IEC61853-2 data analysis method.