Overview - IEC 62153-4-6:2017 (Surface transfer impedance, Line injection method)
IEC 62153-4-6:2017 is an international test method for evaluating the screening effectiveness of shielded metallic communication cables by measuring surface transfer impedance using the line injection method. The standard specifies a controlled procedure for applying a defined current/voltage to the cable screen (outer circuit) and measuring the induced longitudinal voltage in the conductor(s) (inner circuit). Measurements can be made from a few kHz up to and above 1 GHz using common high‑frequency instrumentation. (Edition 2.0, 2017‑08)
Key technical topics and requirements
- Purpose: Determine the transfer impedance ZT (and equivalent ZTE when capacitive coupling is non‑negligible) per unit length to quantify shielding performance.
- Test principle: Injection circuit constructed as a transmission line (parallel wires, corrugated ribbon or flat braid) placed tightly along the cable under test (CUT); injection feature provides coaxial-to-line transition.
- Frequency range: From a few kHz to >1 GHz with standard RF instrumentation.
- Equipment:
- Vector Network Analyser (preferred) or signal generator + receiver (with amplifiers/attenuators as needed).
- Time Domain Reflectometer (TDR) with <350 ps rise time (or VNA return‑loss transformed to time domain).
- Impedance matching: Injection circuit characteristic impedance must match the generator output and load; reflection coefficient of injection feature and injection circuit shall be <0.1 (return loss >20 dB).
- Measurements & evaluation:
- Calibration procedures and measuring setups (near‑end / far‑end) are specified.
- Consideration of capacitive coupling (through capacitance C or admittance YC) and temperature correction.
- Results expressed as transfer impedance, normalized screening attenuation and reported in a standardized test report.
- Measurement precautions: Guidance on reduced primary current, uncontrolled currents, and screen inhomogeneities.
Practical applications and who uses this standard
- Cable manufacturers and designers use IEC 62153-4-6 to:
- Validate and optimize screen designs (braids, foils, drains) for EMC.
- Compare shielding performance across product variants.
- EMC test laboratories and certification bodies use it for compliance testing and performance verification.
- System integrators, telecom equipment manufacturers, procurement/specification engineers and R&D teams use transfer impedance data to assess cable suitability in EMC‑sensitive installations (industrial control, telecom, automotive wiring, data centers).
- Useful for troubleshooting EMI issues, specifying procurement limits, and documenting screening performance in technical datasheets.
Related standards
- Other parts of the IEC 62153 series (Metallic communication cable test methods), including IEC 62153‑4‑1 for background on transfer impedance concepts and related measurement techniques.
Open preview (PDF)Metallic cables and other passive components test methods - Part 4-6: Electromagnetic compatibility (EMC) - Surface transfer impedance - Line injection method
