scope:

This part of IEC 60793 establishes uniform requirements for measuring the cut-off wavelength of single-mode optical fibre, thereby assisting in the inspection of fibres and cables for commercial purposes. This standard gives methods for measuring the cut-off wavelength for uncabled or cabled single mode telecom fibre. These procedures apply to all category B and C fibre types (see Normative references). There are three methods of deployment for measuring the cut-off wavelength. • Method A: Cable cut-off using uncabled fibre 22 m long sample, λcc • Method B: Cable cut-off using cabled fibre 22 m long sample, λcc • Method C: Fibre cut-off using uncabled fibre 2 m long sample, λc All methods require a reference measurement. There are two reference-scan techniques, either or both of which may be used with all methods: • bend-reference technique. • multimode-reference technique using category A1 multimode fibre.