IEC 60793-1-44:2023 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 document 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. There are three methods of deployment for measuring the cut-off wavelength:

- method A: cable cut-off using uncabled fibre 22 m long sample, lcc

- method B: cable cut-off using cabled fibre 22 m long sample, lcc

- method C: fibre cut-off using uncabled fibre 2 m long sample, lc.

All methods require a reference measurement. There are two reference-scan techniques, either or both of which can be used with all methods:

- bend-reference technique

- multimode-reference technique using category A1(OM1-OM5) multimode fibre.

This third edition cancels and replaces the second edition published in 2011. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:

a) used the diameter of the fibre loops to describe deployment

b) added Annex D related to cut-off curve artifacts

c) reorganized information and added more figures to clarify concepts.