This part of BS EN 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.
BS EN 60904-8:1998 history
2014BS EN 60904-8:2014 Photovoltaic devices. Measurement of spectral responsivity of a photovoltaic (PV) device
1998BS EN 60904-8:1998 Photovoltaic devices - Measurement of spectral response of a photovoltaic (PV) device