1 Scope
This part of IEC 61300 provides a method to measure the error and repeatability of the attenuation value settings of a variable optical attenuator (VOA). There are two control technologies for VOAs: manually controlled and electrically controlled. This document covers both VOA control technologies and also both single-mode fibres and multimode fibres VOAs. For electrically controlled VOAs, the hysteresis characteristics of attenuation are sometimes important. The hysteresis characteristics can be measured as stated in Annex B.