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Want to learn everything there’s to know about how to read a multimeter. Then let’s show you!
Mastering the multimeter and knowing how to read it properly takes a bit of time. But don’t worry!
Here, I’ll give you several tips on how to work with this device. By the end, it’ll be super easy for you to check electric circuits, components, and equipment to understand how they work.
Now, let’s start with some of the trickiest elements: the symbols.
How To Read Multimeter Symbols
There’s no doubt that the multimeter is a super helpful tool. However, it may come off as a bit overwhelming while using it for the first time.
This is because the device has many symbols and not many labels to know what they mean. So, unless you read the long and tedious manual, it’s easy to get lost.
But don’t let all of those symbols be a concern. In this list, you’ll find what each of them represents. For this section, I’ll be using the Fluke 117 as an example. This device is among the easiest to use and one of the most satisfying due to its incredible accuracy.
Let’s show you all the things you’ll find on one:
Use this button if you want to freeze whatever measurement the device is displaying. This feature comes in handy to remember the reading later on.
Min Max Button
Thanks to this function, the device stores input values. If those values get breached, the device will beep and set a new value.
This button allows you to cycle from one range to another. It’s pretty common to find meters featuring an auto-range function. However, other models can let you choose a specific range.
Now let’s move down to the dial and the symbols next to it.
AC Voltage (V)
You’ll find it as a V with a curvy line below, plus a single straight line above.
This is the function you use to test voltages. It’s a common setting that you’ll use regularly, so get familiar with it at home or work. Typical voltage measurements range within 100 and 240 Volts AC.
DC Voltage (V)
It is represented by a capital V with three hyphens over it, plus a single line above.
Use this setting if your purpose is to test smaller circuits, lights, or batteries. Most of the time, the standard reading will be under 30 Volts DC.
SHIFT: Hertz (Hz)
In this setting, the multimer measures the circuit’s frequency. Keep in mind that some equipment may work with fixed or variable frequency.
AC Millivolts (mV)
It’s shown as an mV symbol with three hyphens and a line over it.
Use this function when the testing subject is a small circuit that doesn’t provide accurate readings on the AC Volt setting.
SHIFT: DC Millivolts. Similar to the previous one, but using DC voltage instead.
Use this setting to measure resistance levels expressed in ohms. This function is super useful for testing fuse conditions.
It is represented by a wave.
When the device detects continuity between two points, it’ll emit a sound. The point of this function is that it allows you to find short circuits and open circuits quickly.
You’ll find it as an arrow that points to the right and a plus sign next to it.
When you’re learning how to read Ohms on a multimeter, this is important to consider (for testing diodes). Of course, you could also use the Ohms setting for that, but the accuracy wouldn’t be as high.
Alternating Current (A)
It is a capital A with a wavy line on top.
By turning the dial to this setting, you can check how much load an appliance draws. Usually, professionals use this function with a clamp attachment.
This is an exclusive feature to specific multimeter models. The function it serves is to avoid false measurement readings often caused by ghost voltage.
And that’s it! Those are the most common symbols you’ll find in a multimeter. If you need more information, check this fantastic video.
How To Read A Digital Multimeter
Reading a digital multimeter is tricky for the inexperienced, but a lot of fun once mastered. That’s precisely the point of this section. Here, I’ll go over the symbols displayed in the display of the device. These will tell you what the multimeter is picking up exactly.
This is what the digital multimeter should display:
- Resistance value.
- Measurement scale.
Keep this information in mind while moving forward.
Here’s what you need to know and do to understand the digital multimeter.
1. Determine the Readout Scale
In the first step, you’ll be identifying the scale of the readout. Do this by looking beside the omega symbol. It should have either a ‘K’ or an ‘M’ next to it.
Typically, the screen of the multimeter displays the ohm level via the omega symbol.
If the resistance is within kilo-ohm or mega-ohm, the screen shows another symbol ahead of the omega. For kilo-ohm (1,000 ohms), the device displays a K. This will change to an M when the resistance reaches mega-ohm (1,000,000 ohms) levels.
For example, say the multimeter’s reading displays 4.3 with nothing more than the omega symbol. This means 4.3 ohms. If there’s a 4.3 reading with a K next to the omega symbol, the measurement is 4.3 kilo-ohms. When there’s an M, the correct reading would be 4.3 mega-ohms.
2. How to Read a Multimeter Resistance Value
The digital ohmmeter scale is super important, just like the resistance value. After all, the resistance value is the main element during the reading procedure.
Usually, the resistance comes in the form of numbers displayed at the display’s front and center. Also, these digits typically go over one or two decimal points.
Not sure what resistance is? Here are a few tips that may come in handy for you.
Resistance measurement indicates the reduction of electric current flowing through devices or materials.
If the digits are high, it naturally means the resistance rating is high, too. Therefore, more energy will be necessary for the integration of a component into a circuit.
Resistance is everywhere. While testing electronic components like resistors or capacitors, the multimeter will display its resistance value.
3. Make Sure the Range Set Isn’t Too Low
This is only necessary if you’re using a multimeter without the auto-range feature. If this is the case, you’ll have to adjust the range manually. Follow these steps to do it correctly.
Set the range at the highest setting possible. This is an excellent tip to avoid setting it too low beforehand. After setting it at the highest, work your way down. Then, continue lowering the range up until the multimeter picks up a reading.
Another tip would be to do this trick even with familiarized components.
Don’t know when the range is too low? Here’s how you can tell:
Look for values such as dashed lines, “1,” or “OL.” These are clear indicators that the range set is too low.
How to Read a Multimeter Amps
To get accurate amps reading, proper configuration is a must. Luckily, this is a process that involves three quick steps. Follow these instructions.
1. Black Probe
Like other measure readings, you must first put the black probe in the “COM” socket. This term stands for “common,” as in common to all measurements. After putting it in this position, there won’t be any need to move it later on.
2. Red Probe
The red probe goes in the socket with the “A” label, which stands for amperage. Again, be careful while doing this. You may get two options for amperage readings in some devices—one for high-amperage measurement and another socket for low and more sensitive reading.
Knowing the difference between the two is simple.
- One socket may have a socket labeled “A.” Commonly, this also has a printed rating next to it.
- The other socket may have an “mA” label. This means micro-amps, and it could have a 300 mA rating printed right next to it.
- If you doubt which one to use, go with the one with the highest rating.
3. Rotary Dial
Start turning the large rotary dial and set it to the amperage setting, corresponding with the socket you’re currently using. This can vary depending on the multimeter model.
- In some devices, you’ll find individual settings for “A” and “mA,” which correspond to the sockets.
- Other devices may have just one “A” setting found on the dial.
- If you have trouble, check the guidelines for your multimeter.
How to Read AC Voltage On a Multimeter
Another fun aspect of the multimeter is the device’s capacity to measure AC voltage accurately. These are the steps to do so:
- Start by turning the dial to the ṽ symbol. Some multimeters may also have mṽ. Then, set the range to the highest setting and turn the dial on ṽ.
- Plug the black lead into the jack labeled COM, and the red one into the jack labeled VΩ.
- Proceed by connecting the test leads and the circuit. First plug the black lead, and then the red one.
- The measurement reading should now come up in the display.
Frequently Asked Questions (FAQs)
Have some doubts about using a multimeter? Here are some questions and answers that may help you out:
What’s the difference between a clamp meter and a multimeter?
This is a common question most people ask. Though similar, the primary purpose of both tools differs from one another.
The purpose of a clamp meter is to measure current or amperage. On the other hand, the multimeter measures voltage but also resistance and continuity. Additionally, some multimeters read low current. So, of course, it isn’t odd to find clamp meters featuring basic multimeter functions and vice versa.
Use a clamp meter if your tests involve high current measurements. However, if you want a versatile tool that does more than high accuracy, go with the multimeter.
Are multimeters safe to use?
Yes, but you must keep some precautions in mind. So here are a few tips on how to do precise readings safely.
- Figure out what you want to measure and plug the test leads in the correct sockets. Otherwise, you’ll risk dealing with an electric shock.
- Be careful while measuring AC voltage. When you’re doing this, don’t let the probe tips touch each other while connected to the electrical circuit.
- Don’t use test leads without proper protective insulation. If you do, your fingers may make contact with the probe conductor. Suffice to say that this would be unpleasant.
- Always check for DC and AC voltages before conducting your tests.
Are cheap digital multimeters accurate?
It’d be easy to assume that cheap devices aren’t accurate. Luckily, this is not the case at all.
The majority of cheap digital multimeters have a platform based on the IC chip, which is surprisingly accurate. This is clearly visible while testing DC voltages, which shows precise readings.
Here are a few reasons why cheap multimeters are a bang for the buck. They can perform the following tests:
- To read voltage accurately.
- To read power polarity.
- To read continuity, whether electrically connected or open.
- To check whether a signal oscillates.
Of course, you’d need a more high-end multimeter if you want consistent accuracy. And for hobbyists or DIYers, cheap digital multimers are perfect.
Why is the multimeter reading 1?
There may be some occasions where the multimeter reads 1, or it may display an OL reading. This is something I addressed earlier, but let’s talk about it more in-depth here quickly.
When this happens, it means that you’re dealing with an overloaded reading. This is a common occurrence that you can fix quickly. All you have to do is adjust the range knob.
Try setting the mode to a higher level, such as 200kΩ or 2MΩ mode. By doing this, the multimeter should now perform with more accuracy and no false readings.
How to check if there’s a short circuit?
While using the multimeter, let the probes touch the circuit. This could go in different ways. If the device reads high resistance, then that means you’re working with an open circuit. The alternative can be very low resistance, going as low as 2 ohms or even less. In this case, there’s a short circuit at hand.
Furthermore, a meter featuring continuity settings will display visual and audible alarms. These will beep and flash while detecting a short circuit.
For electricians, working with ohms and volts is an everyday task. This is why having the right equipment is a must. In that regard, few are as valuable and versatile as the multimeter. As seen in this article, there are many applications for this tool. Use it to read ohms, volts, amps, resistance, and much more.
With the information shared here, now you know how to read a multimeter. Don’t fear it. It’s a bit overwhelming at first, this device can be a lot of fun once you get the hang of it.