Tips on using the multimeter, you don't have to ask for help after you learn it
In life, everyone is inseparable from electricity. As a measuring tool, a multimeter is a rare good helper when we troubleshoot circuit faults and electrical faults. Whether you are an electronics enthusiast or a novice in life. As a man, isn't it shameful to ask for help when something happens at home? So now let me learn some knowledge about multimeters! Once you learn it, you don't have to ask for help, so why not do it?
There are many types of multimeters, and I suggest that you choose digital ones with calipers now. This kind of table is very convenient in practical application and easy to learn. Although there are many files and numbers on the multimeter, in fact, there are not many files that we commonly use. Let me briefly introduce it to you. The most commonly used multimeter is the AC voltage gear (symbol ACV), which mainly measures the AC voltage. The DC voltage gear (symbol DCV) mainly measures the DC voltage. Electrical blocking (symbol Ω) On and off gear (symbol is an icon like a wireless signal). How to use the multimeter specifically, I don't want to talk about it here today. Because it is very clear in the manual, today I will mainly introduce two methods for using a multimeter to detect faults.
The first little method, use a multimeter to detect a break in the wire. Because the outer layer of the wire is wrapped with an insulating skin, the internal breakpoint is difficult to see. It is very troublesome to detect with a traditional multimeter. It needs to be blocked by electricity. Now digital is much simpler, connect one end of the wire to the phase wire, and leave the other end floating. Hold the tip of the black test lead in one hand and the red test lead in the other, and slowly move the tip back along the insulation of the wire from the end of the phase lead. When the voltage reading of the multimeter suddenly becomes smaller (equivalent to one-tenth of the original reading), the breakpoint of the wire is 15CM back from here. This method only needs to destroy one point of the wire to solve the problem, isn't it very convenient? This method can also detect the breakpoint of the electric blanket.
The second small method, use a multimeter to detect short-circuit faults in the circuit. When the wire in the home circuit is damaged or the circuit is aging and causes a short circuit between the live wire and the neutral wire, it is generally difficult to determine where the short circuit point is. At this time, it can be easily found by the resistance method of the multimeter. After the line is short-circuited, the main switch should be disconnected and all electrical appliances should be unplugged. Put the multimeter in the resistance gear, and connect the two test leads to the live wire and the neutral wire respectively. If the resistance value is zero or very small, a short circuit can be determined. It is necessary to measure the resistance value between the live wire and the neutral wire section by section, and if necessary, cut off a section of the wire to determine the short circuit point. This method can also detect the quality of electrical motors.
