The method of using a multimeter to check the internal breakpoint of the wire
In addition to measuring basic parameters such as voltage, current, resistance, capacitance, inductance, etc., the digital multimeter can also be used flexibly to expand the functions of the digital meter and achieve the purpose of using a meter for multiple purposes. Here we use the digital meter to judge the internal breakpoints of wires and cables. The best method: When the internal circuit of the wire and cable is broken, the exact position of the broken line is not easy to determine due to the insulation layer, which can be easily determined by using a multimeter.
Specific method: connect the wire with a breakpoint to the 220v live wire, and hang the other end in the air, place the digital multimeter in the 2v AC position, hold the nib of the black test lead with one hand, and slowly move the red test lead along the insulating skin with the other hand , at this time the meter shows 0.44v, when moving to a certain place, the voltage drops by a few tenths of a volt, and a few millimeters forward from this position is the breakpoint.
For this reason, I did an experiment and found that the wire test is OK, but the cable test effect is worse. The main reason is that the insulation is thick, and the test pen is far away from the core metal. I put a piece of aluminum foil tape on the tip of the red test pen to increase the test area. , the effect is very good, and there is another method to measure the breakpoint of the wire: connect the magnetic head wire of the recorder to the input end of the sound amplifier, stick the magnetic head on the outside of the insulation for detection, and connect the tested wire to the 220v mains live wire, which can be used in the speaker Hear the buzzing sound, and it will disappear after the breakpoint
