EN 3745-705:2007

Overview

EN 3745-705:2007 is part of the European standard series focused on optical fibres and cables for aircraft use within the aerospace industry. Developed by CEN, this standard outlines test methods for measuring contrast in cable identification markings. Its primary goal is to specify a reproducible and accurate process for determining the contrast value between identification markings and the cable surface. Accurate contrast measurement is crucial for ensuring the legibility and reliability of markings used for identification and safety in aerospace environments.

Key Topics

• Scope and Purpose
  • Defines methods for measuring different colour densities in cable identification markings
  • Establishes a reproducible process for contrast measurement
• Test Equipment
  • Specifies the requirements for photometers, lighting equipment, and cable handling devices
  • Details calibration procedures and precautions against external influences and scattered light
• Sample Preparation
  • Emphasizes the need for clean, undamaged surfaces with sharply defined markings
  • Recommends standardized cleaning and handling for consistent test results
• Measurement Process
  • Outlines procedures for setting up and conducting contrast measurements
  • Provides guidance on avoiding heating and distortion during testing
  • Requires measurements at multiple points to ensure accuracy
• Calculation of Contrast Value
  • Details formula and process for determining average contrast from multiple readings

Applications

EN 3745-705:2007 is essential for suppliers, manufacturers, and quality assurance teams involved in the production and maintenance of optical fibre and cable systems for aircraft use. Its methods ensure:

• Reliable Identification: Clear, high-contrast identification markings are vital for maintenance, installation, and traceability of cables in aircraft.
• Quality Control: Ensuring that contrast values meet specified requirements helps maintain consistency across products and batches.
• Regulatory Compliance: Following standardized measurement processes supports compliance with aerospace industry regulations and contractual specifications.
• Safety Assurance: Properly marked cables reduce the risk of misidentification during operation and servicing, contributing to overall aircraft safety.

The standard is particularly relevant to:

• Aerospace OEMs and suppliers developing or delivering optical cables
• Testing laboratories responsible for cable certification and validation
• Aircraft maintenance organizations verifying on-board cabling integrity

Related Standards

Organizations applying EN 3745-705:2007 should also consider related standards for comprehensive compliance and best practices:

• EN 3745 Series: Other parts of the EN 3745 series cover additional test methods for fibres and cables in aerospace applications.
• ISO 7724-1: Paints and varnishes - Colorimetry - Part 1: Principles; foundational for colorimetric measurement techniques.
• CIE 15: International standard for colorimetry, setting requirements for photometer performance and illuminance evaluation.
• Product Specifications: Ensure measured contrast values match the requirements defined in relevant product standards for aerospace cables.

By adhering to EN 3745-705:2007 and its related standards, aerospace industry stakeholders ensure robust, standardized practices for the identification and safety of optical fibres and cables used in aircraft environments. This commitment to quality directly supports operational reliability and regulatory adherence within the sector.