SIST EN 3475-806:2004

Overview

SIST EN 3475-806:2004 is a European aerospace standard developed by CEN, detailing test methods for measuring the attenuation of electrical cables used in aircraft. As part of the broader EN 3475 series focused on aerospace electrical cables, this standard provides precise methodologies to assess cable performance in terms of signal loss, vital for maintaining reliable electrical transmission in aviation environments. It is intended to be used alongside EN 3475-100, which covers general test methods for electrical cables in aerospace applications.

This standard applies to coaxial and balanced cables, specifying the procedures for evaluating attenuation-an essential parameter representing the reduction of signal strength as it travels through a cable. Accurate attenuation measurement ensures cables meet stringent quality and performance requirements for aerospace systems.

Key Topics

• Scope and Application
  Defines methods to measure electrical attenuation specifically for aerospace cables. It covers preparation of test specimens, measurement setups, and calculation formulas.

• Test Methodologies
  Two primary approaches are described:

  • Insertion method: Involves transmitting a harmonic signal through a cable sample and compensating attenuation via a calibrated attenuator.
  • Comparison of input/output voltage or power: Uses measurement receivers or network analyzers to determine insertion loss, especially for cables with attenuation over 3 dB.

• Measurement Setups
  Visual circuit diagrams illustrate test equipment configurations, including generators, attenuators, balancing transformers (baluns), insertion units, and terminators. These arrangements ensure accurate attenuation readings for both coaxial and balanced cables.

• Calculation and Temperature Compensation
  Detailed formulas calculate attenuation per meter at 20 °C, accounting for measured values and specimen temperature during testing.

• Compliance Requirements
  Measured attenuation values must not exceed limits defined by the relevant product standard, ensuring cable performance matches aerospace industry standards.

Applications

SIST EN 3475-806:2004 is essential for aerospace manufacturers, quality control laboratories, and certification bodies involved in:

• Design and manufacturing of aircraft electrical wiring and cable assemblies.
• Qualification testing of electrical cables for use in avionics, flight control systems, and onboard power distribution.
• Quality assurance to verify cable conformity with aviation safety and performance criteria.
• Supplier audits to confirm consistency and reliability in cable attenuation characteristics.

By following this standard, stakeholders ensure that aircraft cables maintain signal integrity, reduce electromagnetic interference, and provide dependable operation under demanding aerospace conditions.

Related Standards

• EN 3475-100: Aerospace series – Cables, electrical, aircraft use – Test methods – Part 100: General
  Provides the foundational test procedures and general requirements that supplement the specific attenuation tests defined in Part 806.

• Additional parts in the EN 3475 series cover tests related to cable resistance, flexibility, flammability, and other electrical properties necessary for aerospace qualification.

Summary

SIST EN 3475-806:2004 is a critical European standard that defines the accepted methods to measure electrical attenuation in aerospace cables. Using well-documented test circuits and procedures, it helps manufacturers and testing bodies ensure aircraft electrical cables meet rigorous performance standards. Compliance with this standard is a key factor in maintaining the safety, reliability, and efficiency of electrical systems on modern aircraft.