How to Use a Multimeter – Simple Steps to Follow – Toolscell
How do you use a multimeter? This is a probably a first question of every beginner who buy the multimeter for first time. Before learning about multimeter usage, you should know about what a multimeter is and what are the parts of it. This article is an ultimate multimeter guide.
As the name suggests, a multimeter is an electrical device that combines the power of different meters: voltmeter, ammeter, resistometer and thermometer. Multimeter packs all these electric measuring meters into a single unit, eliminating the hassle of keeping and maintaining different meters.
There are two types of multimeters: digital and analogue. Analogue multimeters are the legacy old multimeters that use dials and analogue circuits to measure the basic characteristics of electricity and through various components.
Digital Multimeters are also called DMM. A Digital multimeter contains a digital circuit where all other meters are connected in series with the mainboard. The selection, of which tests is to be carried out, can be carried out via a rotating knob. The reading of the measurement is shown via a digital display which is often black and white. But many new and are coming with coloured display and many other features. These features include the IR camera and graphs representations. These modern multimeters are also equipped with data logging and wireless transmission capabilities.
What are the parts of the digital multimeter?
This is the first question of a newbie and beginner after deciding or buying their first multimeter. You can browse our list of best multimeters for beginners where we have listed the multimeters.
First thing first, let’s start the multimeter tutorial with the basic parts of a multimeter. All basic parts on the front of the multimeters are shown in the picture below. As you can see, there are 4 main parts or regions of a multimeter.
The display is an important part of a digital multimeter meter. The display is usefully made of a Backlit monochrome LCD. Monochrome LCDs are cheaper to produce and consume very little power, hence greatly reduces the production costs, and enhance battery timing. Many new digital multimeters feature huge coloured TFT displays. These types of display consume a lot of energy hence these multimeter comes with a rechargeable battery. For example, fluke 279 comes with a coloured TFT screen and it supports the imaging and graphs. It also has Fluke Connect features which allow the multimeter to transfer the data to a mobile application on Android or iOS.
The LCD screen is capable of displaying readings up to a fixed number and count. For a 2000 count display multimeter, the multimeter is capable of showing the resolution of reading for up to 2000 digits. I.e., it can show the reading of 0.001V to 2000V.
A digital multimeter may have one or more buttons to support the different functionality of the multimeter. A single button can perform a single operation, or it can act differently when combined with another button. In the given sample in the image above, you can see there are 8 buttons in the Fluke 87 digital multimeter. These buttons perform the possible following actions:
- Data Hold
- Shift (changes the functionality of other buttons when pressed simultaneously)
- Range Selection (Auto/Manual)
3. Dial (Rotary Switch)
The dial is used to select which measurement is to be taken. In the given image, you can see that the dial is marked with AC Volt, DC Volt, AC Ampere, DC Ampere, Resistance and so on. A Rotary switch is rotated, and measurement is select. The multimeter will switch the internal circuits of different meters depending upon the user selection of the rotary switch.
4. Input Jacks
These are the jacks ports where testing probes are attached to the multimeter. There are at least two jacks in every multimeter. The red jack and testing lead represents the positive side and the blackjack and lead represent the negative side. There are other input jacks too on some multimeters which are used for temperature measurement, k-type probes and microamps and volts. Input jacks are usually protected with fuses that are installed inside them to protect them against any potential voltage or ampere surge through the probes.
5. Manual Ranging Rotary Switch
For auto-ranging multimeter, the dial is simple and you just have to select the measurement. While in a manual multimeter, you also need to select the appropriate expected range of the reading. Kindly refer to the following image:
In the above image, the green box contains the DC Voltage range which starts from 200mV to 600V. The next red box contains the range of AC voltage, 200V to 600V. The next box is yellow which has the range for the DC amperes, from 20micoramp to 10A. Similarly, the blue box contains all the possible ranges of resistance from 200Ohms to 20 Million Ohms.
“Do Follow the manual of your multimeter, it contains all the information about the multimeter. Some good companies like Fluke include a complete how-to guide with their multimeters. Every multimeter is different from others. Therefore for accurate limitation, warning and capabilities of a multimeter, you should always follow the manual. Unlike manuals of mobile phones and other common home appliances, multimeter manuals contain tens of useful information which one must read before using it. These manuals are excellent source for how to use an electrical multimeter for beginners?”
How to Use a Multimeter?
After a brief introduction to a digital multimeter, now it’s time learn how to use a digital multimeter for dummies.
How to use Multimeter to Check Voltage
1. Voltages with Auto Ranging Multimeter
Measuring voltages is one of the basic functionalities of a multimeter. If you know how to use voltmeter, then it should be pretty easy for you. For an auto-ranging digital multimeter, the multimeter will automatically select the appropriate range after detecting the voltage. A user just needs to set the rotary switch to the respective voltage, i.e. to either DC Voltage or AC voltage, depending upon the source of voltage.
Follow these easy steps to measure DC Voltages in a simple AAA battery with an Auto-Ranging multimeter.
Attach the red probe into the red input jack and the black probe into the black (COM) input jack.
Now rotate the rotary switch to the DC Voltage, as all the batteries and electronics work on DC volt. Kindly refer to the picture below.
Now attach the probes to the ends of the battery: red on the positive side and black on the negative side. Press the probes gently against the battery terminals to make the connection stable.
As the connection will become stable, the reading of DC voltage will be displayed on the screen.
2. Voltage with Manual Range Multimeter
In manual ranging, the selection of a specific range becomes tricky, as the user must have an advanced estimate of the maximum voltages of the source. For the given battery you should select 2V on the rotary dial of the multimeter. As the AAA battery has a maximum voltage of 1.5V, therefore choosing 2V is sufficient.
For testing a battery with more than two voltages, you should choose the range of 20V or other close range, available on your multimeter. Kindly follow the following steps to measure a DC or AC voltage source in manual range.
Attach the probes to the multimeter, red to red jack and black to blackjack.
Set the rotary switch to the estimated range of the source, either DC or AC, for example for a 12V Dc battery, you can choose 20V DC on the rotary dial.
Place the testing probes on the battery terminals, as soon as the connection is stable, the correspondence voltages will show on the multimeter screen.
“Don’t worry if you attach red test probe to neutral wire and black probe to positive, it will only reverse the readings, i.e. readings will become negative.”
How to use Multimeter to Measure Current
Using Auto Ranging Multimeter
Just like voltages, the amperes of any device or source can be measured using test probes on the source outlets. Auto-ranging eliminates the need of setting the range manually, just like the voltage, you can set the rotatory knob to DC Ampere or AC Ampere, rest of the work will be done by the multimeter itself.
Connect the probes to the right jack. See your multimeter manual if there is ambiguity or confusion regarding the type of jacks.
Set the Dial switch to AC Ampere (Refer to the following picture).
Connect the probes to the ampere source, red to the positive and black to the negative terminal.
Get the reading on the screen.
Using Manual Range Multimeter
Just like manual ranging in measuring voltage, it is also necessary to set the correct range for measuring the ampere in manual range. The steps to measure amperes with manual ranging multimeter are given as:
Connect the probes to the multimeter. If there are more than two input jacks, check for the label. For example, in a given multimeter, there are two other jacks than a COM jack.
Now rotate the rotary switch to the expected amperes of the source. For the given multimeter, the range from 20 microamperes to 10 amperes is available. Chose any according to the estimated source.
Connect the testing probes to the target locations of the circuit of the battery to check the amperes.
Measuring the Resistance with Multimeter
Using Auto Range Multimeter
Resistance is the opposition to the flow of current through a conductor. The resistance is measured by a multimeter bypassing current through a resistor. Multimeter passes a fixed amount of current through the resistor and the opposition of the current is measured by the multimeter. The step to measure the resistance in an auto-ranging multimeter is quite similar to measuring the current and voltages with it.
Connect the testing probes into the corresponding input jacks.
Set the knob of the rotary switch to the Resistance option (Refer to the image below).
Connect the probe with the resistor on both ends. The display will show the resistance value.
Using Manual Range Multimeter
For a manual ranging multimeter, a user needs to set the value manually for a resistance measurement too.
Connect both probes to the manual multimeter in respective input jacks.
Set the rotary switch to the estimated range of resistance on the dial.
Connect the probes with the transistor.
“How to know which range is correct in manual ranging?
Well, the answer is quite easy, if your manual ranging multimeter display is showing OL or 1, this means your multimeter is overloaded and you need to select a higher range. If the display is constantly showing 0, this means the manual ranging multimeter is underloaded and you have to select a lower range.”
How to use Multimeter to check Continuity?
If you are wondering on how to use a multimeter to test continuity, then this section is the answer. This test measures the connection between two points, if there is a strong resistance between the two points and the current cannot pass fluently, the test will fail. If there is very low resistance among two points, then the connection between the points is established and the multimeter will produce a beep or display the output. This test can also be used to test switch with multimeter.
Connect the testing probes to the respective input jacks.
Rotate the knob and select the continuity test setting on the dial. This step is the same for either manual ranging or auto-ranging multimeter.
Connect the probes with the conductor to check their conductivity or connect to the circuit to check its continuity. The following picture represents the connectivity check between two points on the circuit.
“(Red Warning Box”)
“If you are wondering on how to measure ac voltage with a multimeter, then use Testers. Don’t ever try to measure AC ampere or voltages unless you are sure about it. DC amperes and voltages are safe at a certain level and usually don’t harm a human. On the other hand, AC amperes and voltages are too dangerous, any miss handling can cause the electricity to zap you pretty badly. Therefore, avoid testing the AC outlets, if you need to test the presence of ampere or voltage in an AC outlet, try Testers. You can also use a clamp meter which provides readings without opening touch the source of the ampere/voltages.