1、 The detection of DC resistance in wires and cables is primarily to check the practical conductivity of the wires and cables. Therefore, the data status of DC resistance can directly reflect the quality of the information in the wire and cable, as well as the primary degree of conductivity of the wire and cable. In practical testing, when the width of the cross-section of the wire and cable is flat, the more current passes through the wire and cable, the greater its resistance, and vice versa. When the current is equal, the better the conductivity of the wire and cable, the better its information, and vice versa. In the national regulations on wires and cables, it is clear that the resistance of a conductor is the highest at 20 degrees Celsius. This proves that when conducting resistance testing, when the wires and cables are both at 20 degrees Celsius, the closer the resistance value is to the specified value, the more qualified the sample is. Otherwise, it will be an unqualified product In the detection of DC resistance, the primary methods used are the bridge method and the current method. The electric bridge method is mainly divided into single arm electric bridge method and double arm electric bridge method. When the resistance value is greater than one ohm, the single arm bridge method is used; when the value is less than one ohm, the double arm bridge method is used. Another method is the current method, also known as the micro ohm method, which can guess based on different resistances and then adopt different currents for detection. The scale of this measurement is larger than that of the bridge method. Additionally, in order to reduce the errors and negative impacts presented in the measurement process, it can be achieved through four terminal measurement. The test results are both persuasive and practical

Secondly, the detection of insulation resistance in wires and cables

When measuring insulation resistance, it mainly refers to useful measurements of the insulation function of wires and cables.

. The primary effect of the insulation function of wires and cables is to reduce the occurrence of leakage, short circuit, open circuit, and other situations in the practical application of current. When this situation occurs, wires and cables can actively block the leaked electricity, avoiding serious consequences such as harm to human life and industry. In the detection process, how to distinguish the resistance value of wires and cables to demonstrate the quality of wires and cables is mainly because the insulation resistance of wires and cables is inversely proportional to the length of the wires and cables. That is, the longer the length of the wire and cable, the greater the resistance, and vice versa. In addition, in the calculation of resistance value, the detected resistance value can be multiplied by the length of the wire and cable, and ultimately the final data is the detailed resistance value of the entire wire and cable The primary method used in measuring the resistance value of wires and cables is the high resistance meter method, commonly known as the voltage current method. The primary application of this method is to measure the insulation resistance of some metal cables and multi-core cables. After measuring cables made of metal, it is necessary to immerse the cables in water and conduct insulation resistance tests on single core cables in nearsighted cables. But for multi-core cable blue, it is necessary to connect the other cells of each cable to water. And in the process of measurement, it is necessary to adhere to the stability of water temperature, so that the measured results can be matched with the water temperature at the time, making the experiment more reliable

Thirdly, testing the function of wires and cables

It is not only necessary to test the conductive function of wires and cables, but also to conduct useful tests on the fire resistance, toxicity, flame retardancy, and density of wires and cables.

. In the detection of the conductivity function of wires and cables, when the temperature and current of the wires and cables are stable, the stronger the conductivity of the wires and cables, the stronger the function, and vice versa. In terms of detecting the toxicity of wire resistance, strict testing should be carried out. Experimental mice can be used to release gas from wires and cables, and useful experiments can be conducted under high temperature and heat conditions. Moreover, useful analysis of the gas that occurs during this time should be conducted When harmful gases exceed the limit value, it indicates that the product is not qualified, otherwise it is considered qualified. When testing the fire resistance, it is necessary to confirm that the object being tested is under the conditions of regular testing. The product should be incinerated at the temperature of regular incineration, and if the sample is incinerated within a certain period of time, it should be clarified that the fire resistance function is not good and it is not a qualified product. Otherwise, it is considered qualified. This kind of experiment is for the actual reaction to present the actual situation. In real life, it is impossible for wires and cables to be burned immediately when a fire breaks out, and there will also be a process of looping. In this way, qualified cables and wires will also provide power to one side after the fire breaks out, bringing convenience to rescue efforts. In this regard, flame-retardant wires and cables are not as good as fire-resistant cables. Flame retardant cables cannot be used continuously after a fire, they can only hinder the further extension of the fire for a period of time, and can also save time for rescue