This part of IEC 61753 contains the minimum initial performance@ test and measurement requirements and severities which a fibre optic pigtailed wide wavelength division multiplexing (WWDM) device for monitoring passive optical networks (PON) using an optical time-domain reflectometer (OTDR) satisfies in order to be categorized as meeting the requirements of category C (controlled environments)@ as defined in Annex A of IEC 61753-1:2007. Annex B of this standard provides information concerning the principle and function of the OTDR monitoring WWDM.