Wire and cable testing is an important part of the wire and cable business, the higher quality inspection department, the more trustworthy. So what kind of cable is good quality? What quality testing indicators? The following are several important indicators of wire and cable.
1, DC resistance measurement:
Conductors of wire and cable mainly transmit electrical energy or electrical signals. Wire resistance is the main indicator of its electrical performance, through this inspection can be found in the production process of some defects, such as wire breakage or part of the single-wire breakage, the wire cross-section does not meet the standards , the length of the product is not correct.
2, The insulation resistance test:
Insulation resistance reflects the insulation properties of wire and cable products, an important indicator of the product's electrical strength, dielectric loss, as well as insulation materials in the working condition of the gradual deterioration are closely related. For communication cables, low insulation resistance between lines will also increase the circuit attenuation, crosstalk between the circuits and the long-distance power supply leakage in the conductive core, etc., therefore require insulation resistance should be higher than the specified value.
3, Capacitance and Return loss measurement:
Cable plus AC voltage, there is a current flow through, when the voltage amplitude and frequency of a certain, the size of the capacitor current is proportional to the cable capacitance (Cx). For EHV cables, the current of this capacitor may reach a value comparable to the rated current, becoming an important factor in limiting cable capacity and transmission distance. Therefore, the capacitance of the cable is also one of the major electrical performance parameters of the cable. Through the measurement of capacitance and dissipation factor, it can be found out that insulation dampness, insulating layer and shielding layer are exfoliated and so on.
4, Dielectric strength test:
Insulation strength of wire and cable refers to the ability of insulating structure and insulating material to withstand the electric field without breakdown and breakdown. In order to check the quality of wire and cable products and ensure the safe operation of products, all insulation type wire and cable are generally tested for dielectric strength . Dielectric strength test can be divided into pressure test and breakdown test. The specific voltage value and withstand voltage time are stipulated in the product standard. The withstand voltage test can test the