As the weather gets warmer, it's the time to start renovations. Both the renovation company and the residents are worried about buying fake and inferior wires, which may bring hidden dangers to the overall renovation and housing. In fact, to judge whether the wire is qualified, you might as well weigh it
Check whether the purchased wire has a quality system certification and certificate; check whether there is a factory name, site, inspection stamp, and production date; check whether there are trademarks, specifications, voltages, etc. printed on the wires
Take a wire head and repeatedly bend it by hand. It is good if it has a soft hand, good fatigue strength, a plastic or rubber hand and no cracks on the wire insulator, while inferior wires have poor mechanical strength, poor toughness, and a few bends. It is easy to break at the second time, and there are often broken wires in the wires.
The copper core of the qualified copper core wire should be purple-red, shiny, and soft to the touch, while the copper core of the shoddy copper core wire is purple-black, yellowish or white with many impurities.
Peel off the wire by 2cm, and rub it on the copper core with a piece of white paper. If there is a black substance on the white paper, it means that there are more impurities in the copper core.
Cut a one-meter wire and weigh it. Divide the gram by its square millimeter value. If it is less than 8.5 grams, it will not be qualified, and it will not be used if it is less than 8.3 grams.