A multimeter is a three-in-one electrical measuring device. It measures electric current (amperes), resistance (ohms) and voltage (volts).
Using a multimeter in making various measurements is a simple procedure provided you are conversant with electrical terms and multimeter features. However, using a multimeter to measure voltage is not the same as how you will use it to measure resistance or the current measurement. Each measurement has its specific settings.
Before proceeding with any measurements using your multimeter, ensure that you practice all necessary safety precautions to be on the safe side. Remember you are dealing with electricity which is something that can cost you your life if not properly handled. Look over the battery and ensure it has enough charge. Do not at any point measure resistance with the power on. Also do not conduct measurements above the meters rated voltage.
Another important thing is to ensure that you know the parts of the meter involved in measurements and the denotations. Familiarize yourself with the leads, the position of the function dial, the connection ports and the different readings for the three functions.
It is better to be safe than sorry.
Voltage refers to the electrical potential of a device – that’s the electric pressure in a circuit. Voltage is measured in volts with measurements denoted in V. Also, there are AC voltage and DC voltage where AC refers to alternating current with DC referring to direct current.
Voltage is measured using the voltmeter function. The first step is to switch the multimeter function to the volt setting denoted as ‘V’. Next, locate the test leads and connect them to the multimeter. There are two leads (red and black). Connect the red lead to the terminal labeled VΩ (red input terminal) while the black lead you connect to the common terminal labeled COM. The common terminal connection remains for both the amp and ohm measurements.
Once you have connected the leads correctly, you can now measure voltage. Attach the leads in the following order: the red lead to the terminal with higher potential and the black lead to the terminal with lower potential.
Resistance is measured in ohms and denoted as Ω. Resistance refers to the level to which an electric current is opposed through a conductor. To measure resistance, you will first need to disconnect the power and wiring of the circuit you intend to measure. This disconnection is to ensure that you are not exposed to electrical hazards or dangers.
Once this is done, turn the function dial to ohm (Ω) on the multimeter to provide ohms readings. Next connect the red lead to the terminal indicated VΩ and, once again, the black lead to the common terminal (COM). At this point, the screen should be displaying ‘OL’ (meaning overload). Now, to be able to measure the circuits resistance, connect both leads (red and black) to the specific circuit.
With this method, you will be able to get the ohms readings that indicate how much resistance is available in that circuit.
If you measure current, it means that you measure the flow of electricity charge in a circuit. Current measurement is given in amps. It can be very dangerous if attempted when an open circuit is above the rated voltage of the meter. The standard rating is 300mA.
To measure current, you should set the multimeter to the ammeter function labeled A. After this, you connect the test leads to the terminals in a slightly different manner from the ohms and volts measurements. For amp measurement, you connect the red lead to the terminal reading 300mA and the black lead to the common terminal (COM).
After correct connection of the leads to the multimeter, attach the meter to the circuit where you will have to break the circuit open and attach the multimeter in series between the open points to acquire amp readings.
With this simple guideline on how to use a multimeter, you should be able to achieve accurate readings and efficiency with your meter.
With a multimeter, you do not have to carry a separate ammeter, voltmeter and ohmmeter whenever you are going to work. You can perform all the above measurements with a single multimeter only with a difference in the settings.
Make work easier by adding a multimeter to your toolkit.