IEC TR 60344: Low-Frequency Cable Conductor DC Resistance — The Ultimate Test of Copper Purity

Why Cable DC Resistance Is the “Double Mirror” of Copper Purity and Cross-Section

IEC TR 60344:2007 specifies low-frequency cable conductor DC resistance calculation and measurement guidance. R₂₀=ρ₂₀×L/A — if measured value exceeds nominal, only two explanations: (1) copper purity insufficient (impurities increase ρ); (2) actual cross-section smaller than nominal (fraud). DC resistance measurement is the most direct cable quality inspection method.

TNLab — The deviation between measured and nominal DC resistance is the most direct “evidence” of substandard materials.