How do you test circuits with multimeters?

1 Choose the right multimeter

The first step is to choose the right multimeter for your circuit. There are two main types of multimeters: analog and digital. Analog multimeters use a needle to indicate the measurement, while digital multimeters display the value on a screen. Digital multimeters are more accurate, easy to read, and have more features than analog ones. However, analog multimeters are cheaper, more rugged, and faster to respond to changes. You should also consider the range, resolution, accuracy, and safety ratings of the multimeter before buying or using one.

2 Set up the multimeter

The second step is to set up the multimeter for the measurement you want to make. You need to connect the probes to the appropriate terminals on the multimeter and select the correct mode and range. For example, if you want to measure voltage, you need to connect the red probe to the V terminal and the black probe to the COM terminal, and select the AC or DC voltage mode and the suitable range. You can use the auto-range function if your multimeter has one, or manually adjust the range until you get a stable reading.

3 Turn off the power

The third step is to turn off the power to the circuit you want to test. This is important for your safety and to avoid damaging the circuit or the multimeter. You should also discharge any capacitors or batteries in the circuit, as they can store electric charge even when the power is off. You can use a resistor or a light bulb to discharge them safely. Never touch the circuit or the probes with your bare hands, and always wear protective gloves and goggles.

4 Connect the probes

The fourth step is to connect the probes to the circuit points you want to measure. Depending on the type of measurement, you need to connect the probes in series or parallel with the circuit element. For example, if you want to measure current, you need to connect the probes in series with the circuit element, which means breaking the circuit and inserting the multimeter between the two ends. If you want to measure voltage or resistance, you need to connect the probes in parallel with the circuit element, which means touching the probes to the two terminals of the element.

5 Turn on the power

The fifth step is to turn on the power to the circuit and read the measurement on the multimeter. You should observe the polarity, sign, and unit of the measurement and compare it with your expectations. If the measurement is too high or too low, you may need to change the range or mode of the multimeter, or check for errors in your circuit or connections. You should also record the measurement for future reference or calculations.

6 Repeat the process

The sixth step is to repeat the process for other measurements you want to make on the circuit. You may need to change the mode, range, or terminals of the multimeter, or move the probes to different points on the circuit. You should always turn off the power before changing anything and turn it on after connecting the probes. You should also compare the measurements with each other and with your design specifications or calculations to verify the performance and functionality of your circuit.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?