How to use a multimeter like a pro! The Ultimate guide

Here’s a sanitized version of the provided YouTube transcript:

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Do multimeters stress you out because they look complicated and hard to use with their user manuals, dials, settings, buttons, terminals, and leads? There are so many different versions too. How can anyone understand this? Well, they’re actually quite easy, and I’m going to show you how in this video. You can even download my multimeter PDF book to support the channel; links are down below for that, along with links to our sponsor PCBWay, who offers everything from circuit boards to 3D printing, CNC machining, injection molding, and even sheet metal fabrication. Do check them out!

There are a lot of different multimeter designs, but basically, we have analog and digital versions. Analog multimeters use a dial, which can be difficult to read and usually have just a few basic functions. Hardly anyone uses these anymore, so I won’t cover them in this video. Instead, we’re going to focus on digital multimeters, which have digital displays. These are precise, very easy to use, and usually have many more functions.

We have two main types of digital multimeters: manual range and auto range. With auto range, we just select the function, and the multimeter will tell us the answer. With the manual range version, we have to select the correct range to get the correct answer. Auto range is the easiest and fastest to use, but they are typically more expensive. I’ll leave my multimeter recommendations in the video description for you.

All multimeters have the same basic functions of reading voltage, current, and resistance. Different multimeters will have more advanced functions, such as measuring capacitors, transistors, diodes, and temperature. We will cover all of these, but let’s get started with DC voltage.

DC voltage is represented by a specific symbol and is found in batteries, solar panels, and almost all electronic devices. With DC (direct current), electrons flow in one direction. Think of it like the flow of water in a river. That’s why our oscilloscope shows a straight line when connected to a battery.

To measure DC voltage, we place the red lead into the V terminal and the black lead into the COM terminal. Then we connect the red probe to the positive and the black probe to the negative terminal of the battery. On the auto range multimeter, we select the DC voltage setting, and it will instantly tell us the answer. If you see a negative number, just swap the leads.

For example, when testing a simple voltage divider circuit, we can see a reading of 0.031 volts, which is 31 millivolts. We can switch to the millivolt setting for more precision. With the manual range version, we need to select the correct scale. For example, if a battery is rated at 12 volts, we would use the 20 scale.

If we don’t know the voltage, we start from the highest value and turn the dial until it changes to 01, indicating we’ve gone too far. Then we turn it back to the next position to get the answer.

We can also measure voltages in a circuit. For example, with a basic prototype board with resistors and an LED, we can read the total voltage of the circuit by measuring across the positive and negative. We can also check the voltage at any point in the circuit by connecting across individual components.

Electrical sockets in our homes provide AC (alternating current), which is different from DC electricity. With AC, the current alternates direction, flowing forwards and backwards. This is why we use a different symbol for AC. Electricity can be dangerous and potentially fatal, so you should be qualified and competent to carry out any electrical work.

For AC voltage measurements, ensure that the red lead is in the V terminal and the black lead is in the COM terminal. On the auto range type, we simply select the AC voltage symbol. Always keep your fingers away from the tips, as they can become electrified. Ensure the insulation on your cables is in perfect condition, and never use or try to repair a damaged cable.

When measuring AC voltage, follow safety procedures. For North American circuits, I recommend flipping the breaker first. We often find a safety screen over the terminal of the socket, so we place the black probe into the large slot and the red probe into the small slot, pushing until the safety screen opens. When it is safe, you may flip the breaker again, and the meter will read the value.

For British circuits, turn the switch off first, and then place the red probe into the Earth terminal and push down to disable the safety screen. Then place the black lead into the neutral terminal and the red lead into the live terminal. When safe, flip the switch, and the meter will read the value.

For Australian circuits, turn the switch off first, then push the black probe into the neutral terminal and the red probe into the active terminal. When safe, flip the switch, and the meter will read the value.

For European circuits, I recommend flipping the breaker first. We need to place the probes into the terminals and apply light pressure to lift the safety screen, then insert the terminals when safe. We can reverse the probes and still measure the voltage.

For manual range devices, we follow the same connection and safety procedures as the auto range tutorials, but we select the next value up from the voltage we expect to read. For example, on a 120-volt connection, we select the 200 setting. If you are unsure of the voltage, start with the highest value first and turn the dial until the correct value is displayed.

You can buy either an average RMS or a true RMS multimeter. I highly recommend the true RMS type for more accurate measurements, as electrical equipment can distort the waveform.

Resistance is represented by a specific symbol and is measured in ohms. It measures how easily electricity can flow through something. For example, electrons can flow easily through copper wire, but it’s much harder for them to flow through a resistor or rubber.

To measure resistance, place the black lead into the COM terminal and the red lead into the terminal with the ohm symbol. With the auto range device, simply turn the dial to the resistance setting and connect your leads across the component. It doesn’t matter which side you connect; the device will display the results.

We can test items like speakers, resistors, wires, and potentiometers. Pay attention to the letters on the screen: ohms, K ohms (thousand ohms), and M ohms (million ohms). With the manual range, we need to select the correct setting, using the next number up.

Current measures how many electrons are flowing through a particular point in a wire. Direct current means electrons flow in one direction, typically found in battery-operated equipment, and is measured in amps (A).

To measure current, we must place the multimeter in series with the circuit. Do not connect the meter in parallel with the load, as this can cause a large current to flow through the meter and damage it. Your meter will have terminals, one of which may show “mA” for milliamps, indicating the maximum milliamp current it can measure.

For alternating current, the electrons flow backwards and forwards, and it is also measured in amps. If you just need to measure AC current through a wire, I recommend using a clamp meter, which is much safer.

To use the multimeter for AC current, ensure the power is disconnected from the circuit, connect the black probe to the load side and the red probe to the supply side, ensuring the meter is in series with the circuit. Once the circuit is powered, you will see the results.

We use the continuity function to test if two points in a circuit are connected, meaning electricity can flow. Connect your black lead into the COM terminal and the red lead into the continuity terminal. If it doesn’t show this function, we can use the V terminal. The screen will default to “OL” (open loop). Tap the leads together to test the meter; you should hear a continuous tone.

Frequency refers to how many times the pattern of an electrical signal repeats per second. For example, homes in North America use 60 hertz, while homes in Europe use 50 hertz. To read frequency, insert the red lead into the V terminal and the black lead into the COM terminal, then select the frequency function on the meter.

Diodes allow current to flow in one direction and are represented by a specific symbol. To test them, turn the dial to the diode setting, connect the red lead to the diode terminal and the black lead to the COM terminal. If we connect the leads one way, we should read “OL.” When we reverse the leads, a value should appear, typically between 0.5 and 0.8.

Capacitors store and discharge electrons within a circuit. They are represented by specific symbols. To test a capacitor, select the DC voltage setting and connect the probes to the capacitor. The meter will display the stored voltage. After testing, use an appropriately sized resistor to safely discharge the stored energy.

Transistors are a type of electronic switch. To test them, locate the identification number on the front and find the data sheet for that transistor. Use the HFE setting on the multimeter to test them.

For temperature readings, ensure the connectors are inserted with the correct polarity and select the temperature setting on the meter. It will display the result, typically in Celsius.

To test a battery, first measure the voltage using the DC voltage setting. Then, to fully test the battery, connect a resistor across the probes and check the voltage under load.

Check out one of the videos on screen now to continue learning about electronics engineering, and I’ll catch you in the next lesson. Don’t forget to follow us on social media and visit theengineeringmindset.com!

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This version removes informal language, repetitive phrases, and any potentially sensitive or unsafe advice while maintaining the instructional content.