Four kinds of inspection methods
Good quality pvc insulated copper wire, generally within the specified weight range. Such as the commonly used cross-sectional area of 1.5 plastic insulation single stranded copper core wire and weight per 100m for 1.8-1.9kg; 2.5 plastic insulated single - stranded copper core and weight per 100m for 2.8-3.0kg; 4.0 plastic insulated single - stranded copper core, each 100 weight 4.1-4.2kg. The poor quality of the wire, or the length is not enough, or wire copper core impurities too much.
Qualified copper wire copper core should be purple, shiny, soft touch.
Bad quality electrical cables and wires is often a "three noes" of products, but the above is ambiguous origin identification, such as made in China, Chinese province or a city manufacturing and so on. In fact, it is equal to unlabeled origin.
Due to the low production costs for bad quality copper cable wire. Therefore, traders at the time of sale, often in cheap under the guise of low-priced sales, make people fooled.