What is Multimeter: Definition and 85 Discussions

A multimeter is a measuring instrument that can measure multiple electrical properties. A typical multimeter can measure voltage, resistance, and current, in which case it is also known as a volt-ohm-milliammeter (VOM).
Analog multimeters use a microammeter with a moving pointer to display readings. Digital multimeters (DMM, DVOM) have numeric displays and have made analog multimeters obsolete as they are cheaper, more precise, and more physically robust than analog multimeters.
Multimeters vary in size, features, and price. They can be portable handheld devices or highly-precise bench instruments. Cheap multimeters can cost under US$10, while laboratory-grade models with certified calibration can cost over US$5,000.

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  1. electricx

    What causes voltage between AC Mains phase and me?

    So my question is that if i put other lead of multimeter to my hand and other lead to socket 230 phase wire why it shows 150 volts when i stand at floor and 80 volts when i stand at carpet? what causes those voltages? And yes i know doing that could be dangerous. It also shows weird voltage if i...
  2. M

    I The multimeter is not displaying mv of strain gauge in circuit

    i have made the wheatstone bridge( 3 resistors and 1 strain gauge) circuit but multimiter is not displaying anything , please need guide
  3. N

    Earth ground meter Vs Multimeter

    Dear forum please help me with the following understanding: There is (are) such equipment Earth ground testers (https://www.fluke.com/en/products/electrical-testi...) - it is used to measure grounded electrical systems or to measure. Such equipment is having multiple poles that are attached to...
  4. kma

    How accurate is a multimeter when measuring current

    Hi. I want to ask a quick question, how accurate are multimeters? Like is every current detected on a multimeter a legitimate current or can it sometimes detect false currents, and can it miss any currents that are there? And how accurate are the values on there when it comes to what the current...
  5. cemtu

    Ways to test a switching IC like TOP266EG with a multimeter?

    What are the ways to test a switching IC TOP266EG with a multimeter?(measuring it outside of card circuit)(after uninstalling the component from the card) Link to the datasheet: TOP266EG Datasheet(PDF) - Power Integrations, Inc. (alldatasheet.com) Here is the DATASHEET picture: TOP266EG IC...
  6. PhysicsTest

    Measuring Phase to Phase voltage using Multimeter

    I want to understand the concept of measuring the phase to phase voltage using multi meter. For example if i want to measure R-Y voltage, i connect the positive probe of the multi meter to the R phase and the negative probe to the Y phase. But both phases will be sinusoidal, so how does it...
  7. ARoyC

    Measuring Capacitance using a basic Multimeter

    Is there any way to measure the capacitance of a capacitor indirectly using a multimeter that does not have the option to measure capacitance directly?
  8. P

    Building a DIY multimeter for my school project

    Hello all, I am a college student from the UK and as part of my course i have to do a project, I have been given a project to do which is to Design a portable electronics circuit that can be used for training. It must be; Able to measure current, voltage and resistance. Operate on 10 Volts DC...
  9. L

    Engineering Multimeter values different and fluctuations

    I measured current through a parrallel circuit and my multimeter fluctuated massively and compared to theoretical values they are miles out. multimeter was changed over to ampmeter. I used duel power supply. Throughtout the measuring i kept getting short circuits. The circuit on the...
  10. J

    Detecting metals with a capacitance multimeter and a circuit

    A makeshift metal detector can be made if you have an accurate INDUCTANCE meter and a coil of a large diameter. Instead, I've got a capacitance meter, this one: http://www.pw-electronics.co.uk/DMM.pdf How can a little circuit be added (like a capacitor with a resistor in series or in parallel...
  11. T

    Electrons cannot sense electrostatic force?

    Why there is not voltage or current just for 1ms if I connect a multimeter ground to the negative terminal of a DC power supply or charged capacitor? Why electrons in measure lead and DMM device cannot sense a bulk of electrons (or lack of it)? I tried with an 5kV DC power supply too. In an...
  12. Wrichik Basu

    Are multimeters accurate when measuring different voltage and resistance ranges?

    I was thinking of buying a multimeter. The one that I intend to buy is this: https://www.electroncomponents.com/Digital-Multimeter-MAS830L I haven't used multimeters a lot. This is the dial of the one that I want to buy: Let's take a specific example of the AC voltage section. It has two...
  13. F

    How does a digital multimeter measure conductance?

    Preface to thread: Back in October I created a thread titled "How does a digital ammeter work?" That thread was about how digital ammeters measure current. The purpose of this thread is to learn how digital multimeters measure conductance, not voltage. This is a separate issue for 2 reasons...
  14. F

    Measuring the current from a micro generator affects its output?

    I am performing an experiment where I have built a scale model of a wind turbine, and am measuring the current it can produce with a micro generator. I am using a standard multi meter and the micro generator is DC. I do not know much about the topic, but whenever I start measuring the current...
  15. A

    Question about multimeter continuity

    Hi guys , i am working in the automotive industry today i encountered a weird electrical issue and i am sure you guys have an explanation , i was using my multimeter to check continuity between different stuff , by mistake i put the leads on the car battery terminals i found the multimeter...
  16. M

    I Error of a measurements taken with a multimeter

    Hi, normally when we take a measure with a multimer we consider the error given by this type of tables: http://www.transcat.com/media/pdf/mete35xp.pdf Do you know how these errors are calculated?
  17. C

    Is the STMicroelectronics L7912CV Voltage Regulator Suitable for a +12V Output?

    [mod note: thread moved from homework forum] I have this Mouser voltage regulator https://www.mouser.com/ProductDetail/STMicroelectronics/L7912CV/?qs=sGAEpiMZZMug9GoBKXZ75xbXFDWiKqpmvrbz5I0HaKg%3D Wired according to datasheet https://www.mouser.com/ds/2/389/l79-974159.pdf see insert photo...
  18. A

    Questions about Using My Multimeter

    So I'm fairly new to electronics. I took physics 2 in college and thought I'd give the hobby a try. I started with a very basic circuit. Just a power supply connected to a light-bulb. However, as simple as it was, I had several questions when taking the reading of my circuit with a multi-meter...
  19. T

    Understanding current measurement on an irregular waveform

    I hoped to use a Keithley 2400 source meter to generate a ~120Hz AC signal by outputting a 2-point sweep from 1A to -1A on an infinite trigger. The waveform image is attached below. The end goal is a resistance measurement for bulk semiconductor materials, we prefer AC measurement to avoid...
  20. H

    Multimeter Peak Voltage Reading

    Hi, I need to find the peak voltage of the ac current produced by the sensor connected to the alternator on my motorcycle. The workshop manual recommended a peak voltage adapter which goes on a multimeter. I don't want to buy this expensive thing. I was wondering since Vp=Vrms*sqrt (2). I can...
  21. H

    How Do Electrical Meters Like Voltmeters, Ohmmeters, and Ammeters Work?

    Recently I asked why with a multimeter you should not measure the resistance of a fuse in a car while there was still power reaching the fuse but why it was ok to measure the voltage. I was told the way resistance is measured is a small current is sent by the meter for the calculation to be...
  22. H

    Automotive Voltage check on car electrical components

    Hi I watched this video of a guy testing a fusebox with a multimeter: if you skip to 6:10 he uses a multimeter on a particular fuse and when putting the black lead on good ground of car and red lead on either side of the fuse he gets the same reading on both sides. He even comments that there...
  23. Wrichik Basu

    Problem in identifying terminals of a capacitor of a fan

    I have a capacitor from a fan. The electrician says it's dead, but I think he is lying. I want to test it with a multimeter. But I can't identify which terminal is positive or negative as it's old and from local company. A poor video of the capacitor is below: A few pics from the video...
  24. G

    Testing an ABS sensor with a multimeter

    As I understand it, there are two main types of ABS sensor - variable reluctance, two-wire and Hall effect, three-wire. The sensor I wish to test is the former. My meter has a frequency and duty cycle button, but which range should I use - AC or DC? I plan to test at the sensor plug while...
  25. T

    Whats wrong with my multimeter?

    I am very new to electronics. On 200M a resistor is "00.9". I go to 20M it is "0.00" and on 2M it is " .000" I thought that "00.9" on 200M means 0.9 MegaOhm so it will fit in the 20M and 2M range - so I get something like 0.945 on 2M but I do not.. What do I do wrong? Details: Multimeter type...
  26. T

    Using a multimeter as an ammeter

    Homework Statement When I connect just the multimeter (as shown in the diagram) to the power source by inserting the lead into the mA connection and change the setting to read the current on the multimeter, it reads 0. When I change the lead connection from mA to A, the power source circuit...
  27. nothing909

    Which Multimeter is More Accurate: ±1%+2 or ±2.5%+2?

    Homework Statement Which multimeter is more accurate? Homework EquationsThe Attempt at a Solution Which multimeter is more accurate, one that is ±1%+2 or one that is ±2.5%+2 I don't know how to read it, is it the higher percentage one that's more accurate or the lower percentage one? I think...
  28. 3301

    Can You Measure Electricity Without Probes?

    So yeah... Is there a way of doing " measuring " electricity and not using probes? Laser perked?
  29. B

    How does a Digital Multimeter work?

    Can someone kindly explain the exact working of a digital multimeter? I know the basic idea, that everything measured (current, resistance, etc..) is converted to volts. But what happens after? How does the digital part come into this? Thanks in advance.
  30. N

    How to convert Ohms to luminosity?

    So, I recently joined a stargazing club, and for our summer activity, we're supposed to use a telescope, a photoresistor, and a multimeter to measure the luminosity of the moon. I know that luminosity can be calculated with the equation, L = σ AT 4, and that brightness can be measured with the...
  31. Nugatory

    Odd multimeter readings with AC->DC wall adapter

    Is there any reason why my basic Radio Shack multimeter might consistently read high when I use it to test the output voltage of an AC->DC wall adapter? I try it on a 4.5V adapter rated for a few hundred mA and it reads close to 10V... I try it on a 6V one and it reads around 12V... but then...
  32. S

    Multimeter selection, what to look for?

    I am trying to build a laser diode driver circuit which which should give a required output of around 1.25v and 200-250mA, I have been having problems with this and want to start inspecting it with a multimeter. The only problem is, I don't have one and really don't know how to select the...
  33. I

    Can I use a multimeter on a multimeter?

    So I have two cheap multi-meters and I've been going around the house and my parents car testing it on voltage. One multimeter I can take out the circuti board, I can see the fuse, and resistors and the conductive path lines. So what I am wondering is if I can use my second multimeter (they are...
  34. I

    What does hFE mean on a multimeter and what is it exactly for?

    It is an option on the multimeter, I have read a little bit saying it has to do with transistors and it is a "test" for it...
  35. I

    What are ways in which a multimeter can "break"?

    The digital multimeter I have says "Overload protection: F 250mA/250V Fused (10A range unfused) Max. Input Current: 10A (For inputs >2A: measurement duration<10 secs, interval > 15 minutes)" It also says in the manual that the 10A jack is not fused...
  36. I

    How many volts can a multimeter read?

    I have only tested mine (it is a cheap one $20) it on a 9V battery, what is the limit? My multimeter starts from 1000V DC then 200,20, 2000m,200m... I am a noob with this so sorry if I don't make sense
  37. ranju

    Measuring Resistance with a Multimeter: Disconnect from Circuit?

    While measuring the value of resistance using multimeter..why we disconnect it from circuit..even if the power supply is of? Since ther's no power supply it will'nt affect the readings...?? Does it?:rolleyes:
  38. G

    Broken Multimeter: Get New or Fix with Soldering?

    Since it's my first time playing around with a multimeter, i finally short-circuited it, tried to measure a current incorrectly, so now my fuse is burnt... The problem is, the fuse is soldered on my multimeter. What should I do, get another multimeter or get a soldering gun and try to fix it...
  39. R

    Grounding Test: Ordinary Multimeter vs Special Tool?

    Can the point to point test, (to determine the resistance between the main grounding system and all the major electrical frames, system neutral, etc) be made with an ordinary multimeter or does it need a special ground test tool? The NETA value of 0.5 ohm is widely accepted?
  40. J

    Multimeter reads different current with LED in series?

    I need help. I was under the impression that LED's in series should have the same current running through them and one's in parallel should have different currents because of the voltage drop variation in the individual LED's. When I put them in parallel, my multimeter shows the voltage across...
  41. A

    If I have a metal mesh can I test it's resistance with a multimeter?

    Is it possible to measure the resistance across a wire mesh with a multimeter? Thanks.
  42. N

    Multimeter (VOM) Design in Electronics Engineering

    Homework Statement The statement is this one... (from the horowitz "The Art of Elctronics") http://www.electroyou.it/forum/download/file.php?id=13691 Homework Equations How should I proceed, i really didn't understand how this VOM works, i mean, i understood, that there a max scale...
  43. B

    Internal resistance of multimeter

    Homework Statement I am taking a class in circuit analysis and am trying to measure the internal resistance of the Radio Shack multimeter. The internal resistance (unknown) is R_x. A battery (with voltage V_s) is available along with a resistor R that has the same order of magnitude of R_x...
  44. R

    I using my digital multimeter

    Hi, this might seem like a really stupid question, but I am not sure how the scale works on my digital multimeter. I am trying to measure the resistance across a photocell in the light and in the dark. I was given this digital multimeter as a gift, but am unsure how to use it. The...
  45. F

    Multimeter Questions about damage.

    Is it possible to damage the continuity tester if the leads are hooked to a battery? For a clamp on AC amp meter; Is it possible to damage the sensor if put around a DC hot wire in a circuit? I am so surprised it is difficult to find events of people damaging their meters. God knows the...
  46. F

    Was this enough to damage Multimeter?

    This is the MM I am using : http://www.sears.com/shc/s/p_10153_12605_03482139000P I made a little electric motor powered by 1.5 volts. However, like the newbie I am, I thought you could measure R on a live setup. Of course the reading was probably wrong, but could this have damaged my meter...
  47. S

    Multimeter current level when measuring resistance

    Hi, When using a multimeter to measure resistance, what is the used current level of the multimeter? I am using Fluke 77 IV Series Digital Multimeter. Thanks.
  48. B

    Understanding Fluctuations in Multimeter Readings

    When using a multimeter, how come the values for the current and voltage fluctuate?
  49. A

    Is it possible to measure the resistance of n-Si or p-Si using multimeter?

    As the title says, is it possible? I was thinking that in order for the multimeter to measure resistance, it first provides current and checks the voltage, and then by ohm's law gets the resistance. But would it even be possible to provide current to n-type Si bar or p-type Si bar? I know...
  50. R

    Multimeter Ohms exponential scale; formula?

    Homework Statement Hi, I'm asking the usual "what formula gives me these results" question, but with a twist; I'm attempting to make a "virtual" analogue multimeter that replicates a physical piece of equipment, for training purposes. The idea is that a random MegaOhm value will be generated...