EVS-EN IEC 61300-3-7:2021

This part of IEC 61300-3 describes methods available to measure the wavelength dependence of attenuation and return loss of two port, single mode passive optical components. It is not, however, applicable to dense wavelength division multiplexing (DWDM) devices. Measurement methods of wavelength dependence of attenuation of DWDM devices are described in IEC 61300-3-29.
There are two measurement cases described in this standard:
a) Measurement of attenuation only;
b) Measurement of attenuation and return loss at the same time.