How to Measure Cable Breakage with a Digital Multimeter
The method of using a digital multimeter to determine the break point of wires and cables: When there is a break fault inside the cable or cable, due to the wrapping of the external insulation skin,
Make it difficult to determine the exact location of the broken wire. Using a digital multimeter can easily solve this problem. Specific method: Connect one end of a broken wire (cable) to the live wire of a 220V mains power supply, and hang the other end in the air. Turn the digital multimeter to AC2V gear,
Starting from the live wire connection end of the wire (cable), hold the tip of the black probe with one hand, and slowly move the red probe along the insulation of the wire with the other hand. At this time, the voltage displayed on the display screen is approximately 0.445V (measured by a DT890D meter).
When the red probe moves to a certain point, the voltage displayed on the display screen suddenly drops to a few tenths of the original voltage,
The wire (cable) break point is located approximately 15cm forward from this position (the incoming end of the live wire).
When using this method to check the shielding wire, if only the core wire is broken and the shielding layer is not broken, then this method is powerless.
How to use a digital multimeter to detect wire breakage
1. Firstly, prepare a digital multimeter for use, which can easily measure whether a wire is connected or disconnected.
2. Then place a wire on the desktop.
3. Insert the red plug of the multimeter into the far right socket and the black plug into the COM socket.
4. Then turn the middle knob to the small horn.
5. Next, let the metal come into contact with both ends of the exposed metal wire. If there is a sound and there is a numerical change, it indicates that the wire is fine.
6. If there is no sound or change, the value shows 1, indicating that the wire is broken and the resistance is infinite.
