IEC 62153-4-4:2015

Overview

IEC 62153-4-4:2015 specifies a triaxial test method for measuring the screening attenuation of metallic communication cable screens (EMC). The standard covers measurements up to and above 3 GHz (practically limited by transversal waves in the outer circuit at ≈4 GHz) and is designed to test even highly screened ("super‑screened") cables using standard instrumentation. This second edition (2015) replaces the 2006 edition and includes key procedural updates on impedance mismatch handling.

Key topics and requirements

• Test principle: Triaxial measuring set‑up with a concentric outer tube that makes results independent of circumference irregularities and external electromagnetic fields.
• Screening attenuation (a_s): Defined as the logarithmic ratio between feeding power and the maximum radiated power observed from coupling peaks; results are derived from measured coupling voltages and converted to power ratios.
• Frequency range and dynamic range: Designed to apply a wide dynamic frequency range from low frequencies up to the limit of transverse wave propagation (≈4 GHz) to capture performance across relevant EMC bands.
• Electrical parameters addressed: Surface transfer impedance (Z_T), capacitive coupling impedance (Z_F), effective coupling length and its impact on measured attenuation, and the influence of impedance mismatches.
• Impedance guidance (technical change in 2015):
  • Impedance matching adapters are no longer mandatory when the measuring device’s characteristic impedance differs from the test equipment.
  • Reflection loss from mismatch must be accounted for via a calculated correction factor.
• Measurement independence: Measurement results do not depend on outer tube diameter or on outer circuit characteristic impedance provided certain conditions (e.g., outer circuit impedance larger than receiver input) are met.
• Procedure elements: Equipment requirements, cable preparation (coaxial, symmetrical and multi‑conductor), measurement steps, and expression of results.

Applications and who uses it

• Cable manufacturers: for design validation and quality control of cable shields.
• EMC test laboratories: to characterize shielding performance and produce comparable, repeatable results.
• Product compliance teams and procurement: to specify and verify shield effectiveness for telecom, data, and industrial cabling.
• R&D engineers: to evaluate materials, braid/foil constructions and design improvements for high‑frequency shielding.
• Standards writers and test developers: as a reference method to harmonize screening attenuation measurements.

Related standards

• IEC 62153-4-1 - introduction to electromagnetic screening measurements (normative reference).
• The IEC 62153 series - other metallic communication cable test methods.

Keywords: IEC 62153-4-4, screening attenuation, triaxial method, EMC test, metallic communication cable test methods, surface transfer impedance, impedance mismatch, cable shielding measurement.