IEC 61745:2017

Overview

IEC 61745:2017 establishes a standardized procedure for the calibration of optical fibre geometry test sets using end-face image analysis, commonly referred to as "near-field" or "grey-scale" analysis. Published by the International Electrotechnical Commission (IEC), this standard is critical for calibration laboratories, manufacturers, and users of geometry test sets who seek to ensure accuracy and traceability in optical fibre measurements. Notably, the second edition of the standard extends its applicability from single mode to include multimode optical fibre geometry test sets and introduces a new annex providing the mathematical basis for uncertainty calculations.

By following the procedures outlined in IEC 61745:2017, users can achieve reliable calibration of test sets, perform effective evaluation of measurement uncertainties, and maintain the integrity and performance of optical fibre systems.

Keywords: end-face image analysis, optical fibre geometry test sets, calibration procedure, measurement uncertainty, IEC 61745

Key Topics

• Calibration Principles:
  Details the principles and methodology for calibrating end-face image analysis test sets. While the focus is on this type, the principles may be extended to similar test systems.

• Artefacts and Standards:
  Describes the types of calibration artefacts used-primarily calibrated fibre ends and chromium-on-glass masks-and outlines requirements for maintaining traceability to national or accredited standards laboratories.

• Calibration Chain and Traceability:
  Explains the calibration chain, which ensures traceability from national standards down to working standards and operational test sets, supporting demonstrable measurement reliability.

• Uncertainty Evaluation:
  Provides procedures and worked examples for evaluating the combined standard and expanded uncertainties associated with geometry measurements, as well as methods to assess uncertainty in concentricity and non-circularity parameters.

• Verification and Routine Checks:
  Covers procedures for routine verification using working standards to monitor stability without requiring full recalibration, helping to minimize downtime and maintain compliance.

Applications

IEC 61745:2017 is widely applicable across sectors involved in the production, research, and quality assurance of optical fibres and related components:

• Calibration Laboratories:
  To perform traceable calibration of geometry test sets, ensuring their measurement results are consistent and meet international standards.

• Manufacturers of Optical Fibre Test Equipment:
  For initial commissioning, ongoing calibration, and quality control of test sets-both single mode and multimode.

• Optical Fibre Manufacturers and Users:
  Supports validation of fibre geometry (cladding diameter, concentricity, non-circularity) to ensure mechanical and optical performance meet required specifications.

• Routine Quality Assurance:
  Enables routine checks of test set calibration using working standards, extending the calibration interval and maintaining measurement confidence in operational environments.

Related Standards

For comprehensive fibre optics quality management and test set calibration, consider the following related international standards:

• IEC 60793 Series: Optical fibre specifications and measurement methods.
• IEC 60874 Series: Connector and interface standards for optical fibres and cables.
• IEC 61300 Series: Test and measurement procedures for fibre optic interconnecting devices and passive components.
• ISO/IEC Guide 98-3: Guide to the Expression of Uncertainty in Measurement (GUM), as referenced for uncertainty evaluation in calibration practices.

IEC 61745:2017 is a foundational reference for organizations seeking to standardize calibration processes and ensure reliable, internationally recognized measurement results for optical fibre geometry test sets. Adopting this standard enhances measurement confidence, supports traceability, and ensures ongoing compliance within the global optical fibre industry.