IEC TR 62316-2017 PDF

Full title and description

IEC TR 62316:2017 — Guidance for the interpretation of OTDR backscattering traces for single-mode fibres. A technical report providing practical guidance on reading and interpreting optical time-domain reflectometer (OTDR) backscatter traces obtained with traditional OTDRs (excluding polarization OTDRs), and on specific backscattered-power effects that affect unidirectional measurements.

Abstract

This Technical Report explains the backscattering phenomenon as seen on OTDR traces, describes common artefacts (Rayleigh backscatter, Fresnel reflections, noise and dead zones), and gives guidance for interpreting unidirectional and bi-directional traces. It discusses backscattered power effects (including so-called losers and gainers), provides examples for apparent splice-loss evaluation in unidirectional measurements, and adds practical notes on launch and tail cords to improve trace interpretation and measurement consistency.

General information

• Status: Superseded / withdrawn — replaced by IEC TR 62316:2026 (redaction published 8 January 2026).
• Publication date: 12 July 2017 (Edition 3.0).
• Publisher: International Electrotechnical Commission (IEC).
• ICS / categories: 33.180.10 — Fibres and cables.
• Edition / version: Edition 3.0 (2017).
• Number of pages: 21.

Scope

Provides non‑normative guidance for interpreting OTDR backscattering traces for single‑mode optical fibres measured with conventional OTDRs. The report does not cover polarization OTDRs. It refers users to the full measurement procedure in Annex C of IEC 60793‑1‑40 for test methods and complements those procedures with interpretation guidance, examples and practical recommendations (launch/tail cords, handling unidirectional traces, evaluation of apparent splice losses and backscattered power effects).

Key topics and requirements

• Explanation of backscattering mechanisms relevant to OTDR traces (Rayleigh scattering, Fresnel reflections).
• Guidance on representation of backscattered power on OTDR displays and the impact of noise and measurement resolution.
• Interpretation techniques for unidirectional and bi‑directional traces, including identification of false or apparent losses.
• Discussion of backscattered power effects in unidirectional traces (so‑called losers and gainers) and their impact on apparent splice/joint loss.
• Examples for evaluating apparent splice loss from unidirectional OTDR measurements.
• Practical guidance on the use and description of launch and tail cords to obtain reliable traces.
• Recommendations to improve figure clarity and trace-reading consistency for field and laboratory use.

Typical use and users

Used by fibre‑optic test and measurement engineers, field technicians, installation and commissioning teams, laboratory staff, manufacturers of fibres and OTDRs, and standards/quality personnel who need practical guidance on interpreting OTDR traces, diagnosing faults, estimating splice/joint losses, and validating installed single‑mode fibre links.

Related standards

Commonly used together with and referenced by standards in the IEC fibre‑optic portfolio, for example: IEC 60793‑1‑40 (measurement methods and test procedures — attenuation; Annex C referenced for test procedure), IEC 61280‑4‑2 (installed cable plant single‑mode attenuation measurements), IEC 61300 series (connector inspection and test procedures), and IEC 61746‑1 (OTDR calibration for single‑mode fibres). The 2017 report replaces the 2007 edition and itself was replaced by IEC TR 62316:2026.

Keywords

OTDR, backscatter, backscattering trace, single-mode fibre, optical time domain reflectometer, splice loss, launch cord, tail cord, losers, gainers, Rayleigh scattering, Fresnel reflection, fibre testing.

FAQ

Q: What is this standard?

A: IEC TR 62316:2017 is a Technical Report offering guidance on interpreting OTDR backscattering traces for single‑mode optical fibres measured with conventional OTDRs (excluding polarization OTDRs).

Q: What does it cover?

A: It covers the physical causes of features on OTDR traces (e.g., Rayleigh backscatter and Fresnel reflections), how to represent and read backscattered power, interpretation of unidirectional and bi‑directional traces, examples of apparent splice‑loss evaluation, and practical notes on launch/tail cords and backscattered power effects such as losers and gainers.

Q: Who typically uses it?

A: Fibre test engineers, field technicians, installers, laboratory personnel, OTDR and fibre manufacturers, and standards/quality teams who need practical, non‑normative guidance for trace interpretation and fault analysis.

Q: Is it current or superseded?

A: The 2017 edition (Edition 3.0) has been superseded and withdrawn; it was replaced by IEC TR 62316:2026 (Edition 4.0), published on 8 January 2026. Use the 2026 edition for the most up‑to‑date guidance.

Q: Is it part of a series?

A: Yes — it belongs to the IEC 62316 series of Technical Reports on OTDR trace interpretation (previous editions include 2007 and 2017) and is part of the broader IEC TC 86 fibre‑optic standards family, which includes IEC 60793, IEC 61280, IEC 61300 and related documents.

Q: What are the key keywords?

A: OTDR; backscatter; single‑mode fibre; splice loss; launch cord; tail cord; Rayleigh scattering; Fresnel reflection; trace interpretation.