Two Clever Uses of Digital Multimeters
This method can be used to check whether the power cord of household appliances is broken, and also to identify the location of broken wires inside household appliances such as electric blankets and irons.
1, Determine the location of wire breakage using a phase analyzer
Method: Connect one end of the insulated wire with a broken core to the live wire of a 220V AC power supply, and hang the other end in the air. Set the digital multimeter to 2V, start from the live wire end, move the red probe along the insulation of the wire, and the displayed voltage value should jump around a few tenths of a volt. When the red probe is moved to a certain point, the voltage suddenly drops to a few zero volts, indicating that this must be the location of the broken core.
The manufacturer of the ratio tester introduces the two wonderful uses of digital multimeters [DC high voltage generator]
The AC 20V gear of the digital multimeter shows two readings of 6.01V and 0.4V, respectively. Therefore, the 6.01V terminal is the power "fire" wire, and 0.4V is the loose change.
Due to the high sensitivity of the AC gear of the digital multimeter, it is also possible to accurately determine the live wire without touching the internal copper wire and only touching the outer skin of the two power lines. The method is as described above. Due to the fact that the probe tip did not touch the copper wire inside, the induced voltage is relatively small, so the gear with a smaller range should be selected.
2, Distinguish between "zero" and "fire" electricity in the city
Set the multimeter to the AC 20V position, remove the black probe, hold the insulating rod of the red probe, and use the tip of the pen to touch the two holes in the power socket one by one. The one with a larger displayed value is the "fire" wire, and the hole with a smaller displayed value is the "zero" wire.
