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, λ _cc:

– method A: using uncabled fibre;

– method B: using cabled fibre.

There is only one method for measuring fibre cut-off wavelength, λ _c.

There is only one method for measuring jumper cable fibre cut-off wavelength, λ _cj.

The test method in this standard describes procedures for determining the cut-off wavelength of a sample fibre in either an uncabled condition (λ _c) or in a cable (λ _cc) or as a jumper cable (λ _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.