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 provides methods for measuring the cut-off wavelength of cable, fibre, and jumper cable. Two methods exist for measuring cable cut-off wavelength, Lambda cc : - method A: using uncabled fibre; - method B: using cabled fibre. There is only one method for measuring fibre cut-off wavelength, Lambda c . There is only one method for measuring jumper cable fibre cut-off wavelength, Lambda cj . The test method in this standard describes procedures for determining the cut-off wavelength of a sample fibre in either an uncabled condition (Lambda c) or in a cable (Lambda cc) or as a jumper cable (Lambda cj ). Three default configurations are given here: any different configuration will be given in a detail specification. This method applies to all B fibre types. 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.