Multimeter: A User Guide Even Beginners Can Master

Suddenly, the lights at home don't work? The socket has no power? The water heater heats up slowly? These annoying circuit problems can actually be easily solved with a small multimeter. Don't think it's a professional tool for electricians. As long as you spend half an hour learning the basic usage, ordinary household users can also become "home appliance experts". Today, let's talk about the usage scenarios of multimeters in the home. It's guaranteed to be easy to understand, and even beginners can master it in no time!

What is a multimeter?
Simply put, it is a "magic box" that can "see" electricity. It can measure voltage, current and resistance, and also detect whether a circuit is open or closed and determine if components are faulty. Just like a family doctor uses a stethoscope to examine the body, a multimeter is like a "stethoscope" for circuits, helping you find the source of the problem and avoid blind disassembly and repair.

Must-know basics for beginners! 3 fundamental operations of the multimeter
1.Remember the "three don'ts principle"
- Unpredictable unknown voltage: For instance, if the power outlet is out of power, first select the 750V AC setting (the maximum household voltage is 220V), and then gradually reduce the voltage.
- Resistance measurement after power loss: Measuring resistance while the device is powered on can damage the multimeter. When measuring components of household appliances, be sure to unplug the power cord!
- Current setting - Not in parallel: To measure current, it must be connected in series (disconnect the circuit and connect the meter). For example, when measuring the current of a light bulb, you need to cut the wire and connect the meter probes. Beginners should use it with caution (as it is prone to short circuits). In home scenarios, the voltage setting and resistance setting are sufficient.

2. Usage of the brush: Red for positive, black for negative, do not touch metal.
Insert the red probe into the "V/Ω" hole and the black probe into the "COM" hole.
When measuring voltage or resistance, connect the red probe to the positive terminal (such as the live wire of the socket), and the black probe to the negative terminal (neutral wire/ground wire).
Don't touch the metal tip of the meter with your fingers. When measuring 220V, only hold the plastic handle. Safety comes first!

3. Bee-Beep Mode: The most commonly used "dumb function" in households
- Check continuity: If there is a sound (resistance < 100Ω), it indicates that the circuit is intact; if there is no sound, it means the circuit is broken (for example, a fuse has blown or the wire connection is loose).
- Test diode: Connect the red probe to the positive terminal and the black probe to the negative terminal. The display should show around 0.5V (for silicon diodes) or 0.2V (for germanium diodes). Reversing the connection will show "1". If it makes a sound both ways or doesn't make a sound at all, it is faulty (for example, LED light bulbs).