1. Look closely at the label printing, the handwriting is blurred and the address is unknown. It means to look at the printed words on the label and the insulating skin. If there are typos, or the printing is of different shades, or the words are blurred, pay attention to it.
2. Use your fingernails to mark and flick the line , and the line will be cut off. Refers to the use of nails to scratch and pinch the insulating skin. The ones that can be scratched or pinched are generally inferior threads.
3.Twist the insulation skin with your hands, and the color will fade and the characters will be of poor quality. Refers to rubbing the insulating sheath with your fingers. Some inferior insulated wires are easy to fade, especially the red wire. This problem occurs. After rubbing, the color of the thread is left on the finger or the words printed on the thread are wiped off Generally inferior quality Aerial Bundled Cable
4. Repeatedly bend the insulated wire and break (ABC)SANS 1418 Standard three to four times. Refers to repeated bending of insulated wires. Inferior wires are generally of poor quality, and the insulation layer will break after bending 3 to 4 times.
5. Use fire to ignite the wire insulation and spontaneously ignite away from the open flame. It refers to the inferior wire that ignites the insulating layer and can ignite spontaneously after leaving the open flame.
6. Aluminum and copper are commonly used for wire cores, and the color becomes darker and lighter. It means to look at the color of the core, the color of inferior thread is gray and without metallic luster.
7, finely measure the inner diameter and outer diameter, and look at the pine when weighing. It means that if it is not determined by the above 6 methods, the outer diameter and core diameter of the insulated wire can also be measured. The allowable error is ±10%. If the measured value exceeds the allowable error, it is basically a low-quality insulated wire.