First, check the certification mark. Obtain a mandatory certification of the product, should be prominently placed in the product certification mark, that is, "CCC" logo, otherwise, that is undocumented products.
Second, look at the inspection report. Wire and cable as the impact of personal and property safety products, has been listed as the focus of government supervision and inspection, regular manufacturers by the cycle to accept the supervision department inspection. Therefore, the seller should be able to provide a quality inspection department inspection report, otherwise, the quality of the product on the basis of lack of quality.
Third, the detection of insulation and sheath. Insulation and sheath thickness should be uniform without skew, feel should have significant tension and elongation. At the same time, insulation and sheath surface should have the name of the manufacturer, the product type continuous printing logo, mark interval: insulation does not exceed 200mm, sheath does not exceed 500mm.
Fourth, observe the line finish and color. Wire and cable copper conductor for the metal or non-coated metal annealed copper wire, aluminum conductor for the aluminum or aluminum alloy wire, the surface smooth, copper conductor was light purple, aluminum conductor was silver white, otherwise, the conductor is likely to be mixed with other impurities Causing a decrease in conductivity.
Fifth, measured DC resistance. To ensure the quality of purchased wire and cable qualified, you can first purchase from the product to take 3 to 5 meters to the inspection body for DC resistance measurement.
Six, the amount of length. The length of the wire should be 100m, the length should be greater than 100m, Failure to meet the standard lower limit is unqualified.