This part of IEC 61753 contains the minimum test and measurement requirements and severity levels that a fibre optic passive chromatic dispersion compensator (PCDC) using single-mode dispersion compensating fibre (DCF) must satisfy in order to be categorised as meeting the IEC standard, Category C – Controlled Environments. Generally, PCDCs are used to reduce the magnitude of chromatic dispersion (CD) between regenerators by adding CD to the span that has a sign opposite to the total CD of the cabled fibre and components. The requirements cover non-connectorised PCDCs with single-mode fibre at both ends used in single-channel transmission and wavelength division multiplexing (WDM) transmission in single mode fibres (SMF) (IEC60793-2-50, B1/B2/B4).