IEC 60793-1-46:2024

Overview

IEC 60793-1-46:2024 - Optical fibres: Measurement methods and test procedures - Monitoring of changes in attenuation - defines standardized methods to monitor changes in optical attenuation during mechanical and environmental testing. The standard supports commercial inspection of fibres and cables by describing two complementary monitoring techniques: Method A (transmitted power) and Method B (backscattering). It applies to all fibre categories covered: class A (multimode), class B (single‑mode) and class C (single‑mode intraconnection).

Key topics and requirements

• Scope and purpose: Establishes uniform requirements for detecting changes in attenuation caused by optical discontinuities, physical defects or shifts in attenuation slope.
• Two monitoring methods:
  • Method A - change in attenuation by transmitted power (normative Annex A): uses a reference path, stabilized sources, launch apparatus and detectors to track transmitted optical power changes.
  • Method B - change in attenuation by backscattering (normative Annex B): uses backscatter measurement techniques to identify localised or distributed loss changes.
• Common measurement provisions (Clauses 1–10): include apparatus, sampling, specimen preparation, procedures, calculations, results and required reporting.
• Specimen requirements:
  • Minimum specimen length must ensure changes are resolvable by the chosen method and apparatus.
  • End faces must be flat and orthogonal to the fibre axis.
  • When used, a reference specimen sample must be identical in type and stable throughout the test.
• Reporting and calculations: Defines required information to be provided with each measurement and additional data available on request (see Clauses 8–10).
• Illustrative layouts and equipment lists: Annexes include layout drawings and specific apparatus requirements for each method.

Applications and users

IEC 60793-1-46:2024 is practical for:

• Fibre and cable manufacturers - in-line quality control and qualification during environmental or mechanical stress testing.
• Test laboratories and QA teams - standardized procedures for comparative acceptance tests and commercial inspections.
• R&D and product development - evaluating design changes that affect attenuation slope or discontinuities.
• Installers and field engineers - diagnosing degradation mechanisms when combined with other OTDR or attenuation tests.
• Certification bodies - consistent test methods for compliance and contract verification.

Keywords: IEC 60793-1-46:2024, optical fibres, monitoring changes in attenuation, transmitted power, backscattering, method A, method B, multimode, single‑mode, intraconnection, test procedures, measurement methods.

Related standards

• IEC 60793-1-40 - Attenuation measurement methods (referenced normative)
• Other parts of the IEC 60793-1-4X series (1‑40 to 1‑49) cover related transmission and optical characteristic tests (bandwidth, dispersion, numerical aperture, macrobending, etc.).