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## Introdução

Every fixer should know their way around a multimeter, which has just north of a zillion uses for testing electronic components and circuits. Follow along to master the three most basic functions of a multimeter.

Part 1: Testing Continuity

Part 2: Testing Voltage

Part 3: Testing Resistance

1. ## Passo 1 Testing Continuity

• A continuity test tells us whether two things are electrically connected: if something is continuous, an electric current can flow freely from one end to the other.

• If there's no continuity, it means there is a break somewhere in the circuit. This could indicate anything from a blown fuse or bad solder joint to an incorrectly wired circuit.

• Continuity is one of the most useful tests for electronics repair.

2. ## Passo 2

• To begin, make sure no current is running through the circuit or component you want to test. Switch it off, unplug it from the wall, and remove any batteries.

• Plug the black probe into the COM port on your multimeter.

• Plug the red probe into the VΩmA port.

Why only in VΩmA not in 10A

Great question! The VΩmA port is rated up to 200 milliamps (mA), which is the correct range for this demonstration. If you're not sure how much current you're dealing with, go ahead and start with the red probe in the 10 A port instead—it's less sensitive, but can take up to 10 A without blowing a fuse.

Why do we need to make sure that no current is running through the circuit?

When there is another parallel branch with 24VDC power and 4-20mA output, the value of the resistance measured comes as zero. Whats the reason?

3. ## Passo 3

• Switch on your multimeter, and set the dial to continuity mode (indicated by an icon that looks like a sound wave).

• Not all multimeters have a dedicated continuity mode. If yours doesn’t, that’s okay! Skip to Step 6 for an alternate way to perform a continuity test.

I want to search the resistance of gold and see if I have some

What does a sound wave look like?

4. ## Passo 4

• The multimeter tests continuity by sending a little current through one probe, and checking whether the other probe receives it.

• If the probes are connected—either by a continuous circuit, or by touching each other directly—the test current flows through. The screen displays a value of zero (or near zero), and the multimeter beeps. Continuity!

• If the test current isn't detected, it means there's no continuity. The screen will display 1 or OL (open loop).

5. ## Passo 5

• To complete your continuity test, place one probe at each end of the circuit or component you want to test.

• As before, if your circuit is continuous, the screen displays a value of zero (or near zero), and the multimeter beeps.

• If the screen displays 1 or OL (open loop), there's no continuity—that is, there's no path for electric current to flow from one probe to the other.

• Continuity is non-directional, meaning it doesn't matter which probe goes where. But there are exceptions—for instance, if there's a diode in your circuit. A diode is like a one-way valve for electricity, meaning it will show continuity in one direction, but not in the other.

6. ## Passo 6

• If your multimeter doesn't have a dedicated continuity test mode, you can still perform a continuity test.

• Turn the dial to the lowest setting in the resistance mode.

• Resistance is measured in ohms, indicated by the symbol Ω.

How do I test Amps ( ouput from a battery charger)

Thank u so much

7. ## Passo 7

• In this mode, the multimeter sends a little current through one probe, and measures what (if anything) is received by the other probe.

• If the probes are connected—either by a continuous circuit, or by touching each other directly—the test current flows through. The screen displays a value of zero (or near zero—in this case, 0.8). Very low resistance is another way of saying that we have continuity.

• If no current is detected, it means there's no continuity. The screen will display 1 or OL (open loop).

You mentioned that if your meter screen displays 1 or OL

But what happen if it shows other numbers

Like 5.5 or somewhat?

It means you have current flowing which would indicate a good path or circuit. Also means you have a power supply connected which I think was mentioned earlier in the article to disconnect all power supplied, as in a.c., d.c. Especially in a vehicle as running tests on computer module circuits with the vehicle battery connected can damage a computer module circuit..

8. ## Passo 8

• To complete your continuity test, place one probe at each end of the circuit or component you want to test.

• It doesn't matter which probe goes where; continuity is non-directional.

• As before, if your circuit is continuous, the screen displays a value of zero (or near zero).

• If the screen displays 1 or OL (open loop), there's no continuity—that is, there's no path for electric current to flow from one probe to the other.

What does it mean when I first get 1 then the meter jumps to all kinds of numbers and there is no beeping?

9. ## Passo 9 Testing Voltage

• Plug the black probe into the COM port on your multimeter.

• Plug the red probe into the VΩmA port.

10. ## Passo 10

• Switch on your multimeter, and set the dial to DC voltage mode (indicated by a V with a straight line, or the symbol ⎓).

• Virtually all consumer electronic devices run on DC voltage. AC voltage—the kind that runs through the lines to your house—is considerably more dangerous, and beyond the scope of this guide.

• Most multimeters are not autoranging, meaning you will need to set the correct range for the voltage you expect to measure.

• Each setting on the dial lists the maximum voltage it can measure. So for example, if you expect to measure more than 2 volts but less than 20, use the 20 volt setting.

11. ## Passo 11

• Place the red probe on the positive terminal, and the black probe on the negative terminal.

• If your range was set too high, you may not get a very accurate reading. Here the multimeter reads 9 volts. That's fine, but we can turn the dial to a lower range to get a better reading.

• If you set the range too low, the multimeter simply reads 1 or OL, indicating that it is overloaded or out of range. This won't hurt the multimeter, but we need to set the dial to a higher range.

12. ## Passo 12

• With the range set correctly, we get a reading of 9.42 volts.

• Reversing the probes won't do any harm; it just gives us a negative reading.

13. ## Passo 13 Testing Resistance

• To begin, make sure no current is running through the circuit or component you want to test. Switch it off, unplug it from the wall, and remove any batteries.

• Remember that you'll be testing the resistance of the entire circuit. If you want to test an individual component such as a resistor, test it by itself—not with it soldered in place!

• Plug the black probe into the COM port on your multimeter.

• Plug the red probe into the VΩmA port.

Be careful when testing ohms on the circuit board, the best test is to remove the part so you are only testing the part not the circuit around the part. Transistors, resistors, caps need to be removed or at best one leg of the part. One time I had a burn open resistor, then I tested the resistor with my Ohms test I got some resistor reading. This was caused by back feed in the circuit.

14. ## Passo 14

• Switch on your multimeter, and set the dial to resistance mode.

• Resistance is measured in ohms, indicated by the Ω symbol.

• Most multimeters are not autoranging, meaning you will need to set the correct range for the resistance you expect to measure. If you're not sure, start with the highest setting.

Attention, une petite erreur dans la description ci-dessus : il faut remplacer “plage correcte de voltage” par plage correcte de résistance

15. ## Passo 15

• Place one probe at each end of the circuit or component you want to test.

• It doesn't matter which probe goes where; resistance is non-directional.

• If your multimeter reads close to zero, the range is set too high for a good measurement. Turn the dial to a lower setting.

• If you set the range too low, the multimeter simply reads 1 or OL, indicating that it is overloaded or out of range. This won't hurt the multimeter, but we need to set the dial to a higher range.

• The other possibility is that the circuit or component you are testing doesn't have continuity—that is, it has infinite resistance. A non continuous circuit will always read 1 or OL on a resistance test.

Ici aussi petite erreur : remplacer “le multimètre indique 9 volts.” par le multimètre indique .001 Ω

16. ## Passo 16

• With the multimeter set to a usable range, we get a reading of 1.04k ohms.

Easy to understand for a none electrician. Good.

Good tutorial ! Why was measuring AC and diodes not included ?

Very good why can't the manufacturer write these instructions thank you

Yes it would be sweet if manufactures instructions were this clear. Excellent job

All of this is great but what are people going to do with this information? Nothing tells them how to check components for shorts, probably the most common test when looking for failures in electronics.

If this information were coupled with material explaining how to trouble shoot electronic circuits for basic information everyone would have gained a use for their meters. If information went a bit more in depth they would learn to identify failed components. Most of the time anyone can troubleshoot and repair a HDTV set using a multi-meter alone.

Add to your already good work and help people get through the maze of what to do when troubleshooting electronics. Nothing about troubleshooting most electronics is hard to learn. It normally takes a minimal understanding of components to enable anyone to fix something.

The name of the tutorial was “How to Use a Multimeter", so it was mesnst to be an introductory glimpse into how to use a Multimeter. Specific testing of electronics, PCBs, and the like is outside of the scope of this article. However, given the basic understanding of how a mtimetsr works it would be reasonable to expect someone to be able to figure out how to test the circuit board.

Sometimes it's better to send two separate than overly complicated one.

He’s not teaching an electrical engineering course here, simply telling us how to use a multimeter. For me, this instruction told me exactly what i needed to know. Whoever wrote it, great job. For those of you complaining that it doesn’t go far enough, well, in the immortal words of David Letterman, “why don’t YOU try a little harder?”

Very easy to understand tha

Thank you thank you for doing this!! This is all new to me and your posting was sooooo helpful , easy to follow and you went step by step . Your the only place that said some multimeters may not be marked for continuity!!! I was losing it

thanks again for explaining in layman terms .

Thank you verymuch indeed.habib Abolfathi.

and what if the meter has NO symbol (selection) that looks like a sound wave at all ? You didn’t explain that some meters do NOT have that selection … so how would one do the test in another way ordinary in even cheap meters?

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### Autor(a)

#### Jeff Suovanen

Membro desde: 06/08/2013

355.620 Reputação

258 Guias de autoria

### Equipe

#### iFixit Membro de iFixit

Community

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### 122 comentários

Thank you! Never find instructions so easy to follow.

Iwant to know hw to test caperstas

Great stuff!! Thank you.

Super guide, many thanks for posting!

Thank you. Very easy and good training

Very helpful for beginners, thanks for these clear instructions!

great article. thanks

thank you !!! for this info!!!

i did not know i can do this.

Thanks a lot this is very clear and helpful!

Thanks Jeff. I just purchased a cheap mm. All instructions were in Chinese. Your help made sense of it all, so easy.

Iwant to knw hw to test power suply

great, thank you for good description.

Brilliant thank you

It takes an intelligent person to write simple instructions. BRAVO !

It truly does.

so nice Bro...Thanks a lot...

Thanks a lot

Love the resources on the Pro site.

Very good instructions

Nice guide.pl add some additional examples to have better understanding for beginners.Thank you

I'm doing exactly this and mine won't read any voltages, but it will read resistance. I've tested it with multiple batteries that I know work, but I only get a read of 0. What might be the problem?

Very good lesson, helped a lot. Thankyou

This is the best and easiest lesson on using multimeter. Thanks a lot!

Thank you, Haven't used one of these is ages; this was a great refresher!

thanks for a very easy tutorial, it is very helpful!

The basics. Soooo important. Well done, short and concise.

Nice and straightforward guide - thanks buddy.

Had multimeter for a couple years, never knew how to make it beep!

Thank you for these great instructions. The instructions that came with the multimeter were not helpful for a beginner, and these really helped us diagnose our problem.

Thank you for the great instructions. My question and the reason for my looking online for info on using a multimeter was to find out what the various resistance readings mean on a digital tester. I am checking out a defrosting element in my refrigerator and got a reading of 12 or 15 ohms. The information I was reading said a 15-100 ohms meant the element was OK, another book said if medium resistance was found it was OK.

By going online I was looking for the answer as to what is low, medium and/or high resistance ranges are.

I did enjoy your instructions, they were easy to understand.

I have used a meter for a long time. Never had instructions so clear and easy to follow. Thank you very much.

The pictures are also very clear and helpful.

Beautifully put. I truly appreciate the lesson. I've learned something of impirtance. Thank you.

it really useful for begginer

Thanks you for the lesson :)

Hi,

das ist wirklich sehr anschaulich aufgebaut und benutzerfreundlich, vielen Dank dafür!

Wer jetzt noch genau wissen möchte wie Multimeter funktionieren und worauf Sie beim Kauf achten sollte der kann gerne noch auf https://multimeter-tester.de schauen und weiter lesen.

Ich wünsche euch noch einen schönen Abend und einen bestmöglichen Start ins neue Jahr.

LG

Thanks you for the lesson :)

A great introduction for a beginner like me.

Hello . and thank you good read.

Easy to understand...thank you

Thanks and had help me a lot

Had help me a lot. Many Thanks

Thanks, I think I've got it.

Simple and precise. A life saver as I couldn't find the "manual" - one page sheet. Greatful!

Wow I love this I can now read a resistor thanks keep on the good work

Thanks , sometimes need too refresh with the basics.

It is very nice demostration

Sir can i get a book about basics of auto electrical and electronics or soft copy.

Very informative! Easy to understand.

Well written.

Simple and easy thanks

I have been searching a tutorial on getting started with trouble shooting an automotive parasitic draw. I have no background in different types of functions of a mmeter such as continuity, voltage, and resistance, your tutorial was a must have. It gave me an understanding of just the basic terminology of the more advanced tutorials. I give it a major thumbs up, excellent tutorial thanks a million !!!!!!

Easy to follow description. However, I am having trouble diagnosing a microwave diode. Seems I can't do that directly with a multimeter. Is that correct?

Rose - May 9, 2017

Thank you, the instructions that came with my multi meter were clear as mud. Your mini course was very clear and concise.

Thank you. This was very helpful to me. Very clear and easy to understand....

Thank you so much, it is so easy to understand the way you explain.

thankyou very much.

Thanks for supportive/useful post

Excellent please give us more of the same, primarily to help with understanding of the subject matter at a basic level.

Excellent and elegantly simple guide.

Thanks you so much for this.For me as a beginner,I didn't find difficulties in reading this but its fruitful one.

thanks a million

It was just awsome.Before your tutorial it just was looked like some alien device to me and now I think it's having very simple working principle. I am now pretty confident to work with it. A very big thanks.

Indeed awesome. Lots of thanks for such a generous sharing of knowledge. Be blessed

very simple and accurate

Awesome thanks.. I knew you could use this for a lot of things but not this much.

I have a problem with my multimeter (Mastech MY74), the first thing I did was stupid, haven't read the user manual and tried it on a live socket and now it doesn't want to work. I have changed the fuses (600V, 0,4A and 10A), but it still doesn't work. Does anyone have an idea what else could have went wrong and how to test it?

Best regards

Very useful. I liked the statements like ‘this will not harm the multimeter but will show negative reading ‘. For non science folks like me, these questions crop up often so this guide takes away the anxieties.

Nice article with great illustrations.

Apart from measuring DC voltage, resistance and continuity, they can also measure AC voltage, DC current, transistor and Diode checking, which I learnt from here https://circuitdigest.com/article/how-to...

Following the KISS method of instruction!

Very well done!

marvellous explanation for a layman good luck& thanks

Excellent guide. Very well explained and easy to use.

What to say except that you are the best !!!

Good information. Thank

Thanks a lot. :) My fear with multimeter is gone now. I am able to measure with confidence.

Can multimeters be used to measure salinity in water?

Jeff, thanks for your step by step multimeter guide. I have also written https://bestmultimeterreviews.org/ similar article in my blog. But, your article is much better than me.

Simple, easy to understand, well presented. Very helpful thanks.

Literally helped me passed my physics test; thank you!

Thank you very much !! Nicely explained and very easy to read with the pictures provided

Tanks very much….Its really

you put a lot of effort in making this tutorial. I appreciate it.

Thank you. Very clear and thorough.

Thank you for the helpful information, simple for novice to understand.

Cool keep up the good work and thanks

Great for beginners, thanks

thanks for a very easy tutorial, it is very helpful! pl add some additional examples to have better understanding for beginners.Thank you

sateesh

Thank u for the precise description,very very useful for beginners.

A MAZUMDER

thanku for guide!!!

I studied multimeter in my 11th grade and since then, haven’t been around these things for a long time! I was glad to go through the above instructions and as my nephew has been studying physics as well, I was able to guide him through some subjects which really gave me a good day and made my nephew happy. Thanks a lot.

thanks for this info.

Very good explained well. Thank you.

Exceptional directions and explanations for each step. Even an inexperienced user (such as myself) can understand and follow the instructions. So hard to find such detailed instructions for those that “want to be in the know”!! Kudos! You deserve 4+ Stars :)

We thank you for the information

I was always confused about electricity and how to test it but your instructions have given me a better understanding of it. I now have a place to go to for future reference. Thanks.

thanks for the lucid description of the three phases of testing an electronic item; good job!

An excellent guide. Thank you.

Congrats for showing us the best way use it

Excellent guide Thank you!!!!

Easy and simple to understand!! Thank you

Show us the hard stuff like MX10 android box main board how to test thank u

Well. .. thank you, this is awesome

thank you very much

Well done. You've explained it in detail and was completely understandable. Tm

Good Content …………..Easy to Learn!

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When testing a Tweeter the multimeter reads OL on the resistance scale. What does this mean?

What if theres a rechargeable battery that I cannot remove ahead of time ? Can I still do continuity tests with the battery inside if my device is powered off?

Very simple and easy to understand. Thank you very much for your help, now I can use a multimeter now.

Very informative ; Thank you ?

Thank you so much for making it so simple to follow. Because before I new what I was doing I got the all wires mixed up on my car battery. And I nearly melted my fingers to the wires. So thanks again c foley… craigfol659@gmail.com