... GB/T18813-2002 standards, and provides the requirements for transformer copper, testing methods, inspection rules, marking, packaging, transportation, storage and contract ... than 0.20 mm of the strip, the test results for reference only. Table 3, the electrical properties of stripTrademarkConductivity /% ... conductivity.Conductivity = 100% × 0.017241 / resistivity measured. copper foil for transformers