This part of IEC 61300 describes the various methods available to measure the attenuation of optical components. It is not, however, applicable to random mate attenuation measurements as described in IEC 61300‑3‑34 and IEC 61300‑3‑45 nor for attenuation measurements of dense wavelength division multiplexing (DWDM) devices as described in IEC 61300‑3‑29.