How to use a digital multimeter? Introducing 5 Common Methods for Using DMMs!

How to use a digital multimeter? Introducing 5 Common Methods for Using DMMs!

A digital multimeter is a common measuring tool that can be used to measure current, voltage, and resistance. We often use it in maintenance, but some friends don't know how to use it properly. Here I will introduce you to him. Some common ways to use it.

1. Assessing whether a fee is charged or not

The DMM's AC voltage range is very sensitive, even if there is a small induced voltage around it, it can be displayed and used as a test pencil.

Turn multimeter to AC20V gear, hang black probe in air and keep red probe in contact with line or device on side. If multimeter shows a number between a few volts and more than ten volts, it means that line or device is charged. If it is displayed as zero or very low, it indicates that there is no charge.

2. Power line is energized or neutral

Turn multimeter to AC2V gear, hang black probe in air and carefully run tip of red probe along line, and multimeter will read a few volts, indicating that line is energized. If display shows only a few tenths of a volt or even less, it means line is a null line.

How to use a digital multimeter? Introducing 5 Common Methods for Using DMMs!

3. Voltage measurement

Voltage is potential difference between two points, so voltage measurement does not require an open circuit, only two points in circuit need to be detected. Voltage is usually measured in volts (V).

Turn on multimeter and turn dial to V or ṽ (V means DC voltage, ṽ means AC voltage). Select Range to set range to maximum expected value. Plug black probe into common socket and red probe into socket with V.

First connect black wire to lowest voltage point and red wire to higher voltage point. Observe readings of multimeter.

4. Measure current

Current is measured in amps. When measuring current, current must flow through multimeter, and measuring point must cut off circuit, and digital clamps can measure current without breaking circuit.

Turn off power to circuit, turn on multimeter, and turn knob to A or à current (A is DC, à is AC). Turn dial to set meter's current range and select highest estimated value. Plug black lead into meter's common socket and red lead into socket with letter "A" or "mA", where mA is a low current socket.

Disconnect circuit at measuring point, connect black lead to one of two measuring points, connect red lead to other measuring point, turn on power to circuit and observe multimeter.

5. Resistance multimeter

Resistance is an electronic component that prevents flow of electricity. The unit of measure is ohm (Ohm).

Turn off power to circuit. If there are capacitors on board, discharge them first. If possible, remove resistor from circuit to avoid anything that might interfere with resistance measurement.

Turn on multimeter and turn switch knob to Ω resistance. Choose an appropriate range that is slightly higher than expected resistance value. Connect black test lead to common jack and red test lead to Ω jack. Connect black and red wires to two ends of resistor respectively. Observe readings of multimeter.

The above is an introduction to using DMM, hope you find it helpful.