This part of IEC 60904 gives guidance for the measurement of the relative spectral response of both linear and non-linear photovoltaic devices. This is only applicable to single-junction devices.
IEC 60904-8:1998 history
2014IEC 60904-8:2014 Photovoltaic devices - Part 8: Measurement of spectral responsivity of a photovoltaic (PV) device
1998IEC 60904-8:1998 Photovoltaic devices - Part 8: Measurement of spectral response of a photovoltaic (PV) device
1995IEC 60904-8:1995 Photovoltaic devices - Part 8: Guidance for the measurement of spectral response of a photovoltaic (PV) device