Are you planning to buy a multimeter and need help? Here are some timps
How to Buy a Multimeter covers what you need to know to select a meter for DIY electronics. It focuses on the needs for audio electronics, but it’s purposely kept general in nature.
Handheld Digital Multimeters are mainly used to measure resistance, as well as DC/AC voltage and current. Common multimeters can be divided into two types, desktop and handheld digital multimeters depending on their sizes. A handheld digital multimeter is basically composed of Analogue Front End (AFE), MCU, Human-machine interface and Power supply. The design of handheld multimeters should focus on the features of low power, high performance and compact size.
Look for these features when buying a multimeter article tells that multimeters can be handy for troubleshooting PC power problems (I would say it is a must have). But the range of features and prices can be confusing when you’re shopping for one. Before you waste time and money, find out which features are essential and which are merely nice to have.
EEVblog #75 – Digital Multimeter Buying Guide for Beginners
EEVblog #91 – $50 Multimeter Shootout – Extech EX330, Amprobe AM220, Elenco, Vichy VC99, GS Pro-50
$50 Multimeter Comparison and Teardown article tells about a very nice video series on multimeters. Here is maybe the most interesting video from it:
$50 Multimeter Shootout – Part 7 – 15 DMMs Compared! – Teardowns – #0074
119 Comments
Washington Plumber says:
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Tomi Engdahl says:
Why You Shouldn’t Quite Forget The Moving Coil Multimeter
https://hackaday.com/2017/11/08/why-you-shouldnt-quite-forget-the-moving-coil-multimeter/
There was a period through the 1980s into the 1990s, when the transition between moving coil and digital was in full swing. Everyone wanted a digital meter because they were cool. They had both precision and accuracy, instead of saying “That’s about 5 volts”, you now knew it was exactly 4.98 volts.
So we can make fun of 1980s fashions, both sartorially and in test equipment, but what’s the real benefit of a digital meter? It lies in the internal resistance. When you hook a moving-coil meter into a circuit, you are doing work, drawing energy from the circuit being measured to move that pointer. Imagine the meter itself in a hypothetical inexpensive moving-coil multimeter, that has a full scale deflection of about half a milliamp. To take a reading at full scale the meter must then draw 0.5 mA from the circuit being measured. So to give a full scale deflection of 10 V for example the meter must have a resistor in series with it of value 10 KΩ, and measuring a voltage thus involves placing what is in effect a 10 KΩ resistor into the circuit in question. Most decent moving coil multimeters had meters with much lower full scale deflections that required greater series resistances, but the principle was the same. A moving coil multimeter loads the circuit it was testing, altering its characteristics.
The problem of meter resistance was one for which there were solutions in the age before digital meters. Many decades ago you could buy a valve (tube) voltmeter
So why should you have a moving-coil meter on your bench, if digital meters are so good? Aside from looking a bit retro and never having to worry about the batteries running out, that is. The answer lies in being able to measure voltages that change. If you have ever worked with radio or with analogue circuits that require adjustment you will know something of this, tuning for a peak or a trough is extremely difficult when you have no view of the trend. A typical use for a moving coil meter here is to set up an RF amplifier by tuning a tank coil, there will always be a peak in the current drawn by the amplifier as the coil reaches resonance.
The moving coil meter of choice here for the last 30 years or so has been a venerable Avo 8. This is the classic mid-twentieth-century multimeter, a large and heavy Bakelite unit with an extremely high quality meter lurking within it.
MF47 can be had from the usual Chinese suppliers for about £15, or $20. It’s not the most compact of multimeters, having a front panel slightly larger than and being about three times as thick as a DVD case.
Comments:
A vintage needle meter – hipster engineer.
Brain-fart, but we use to have both. The analog was pretty cheap, even back in the day.
There’s things that you should probably check out with other types of equipment that you can at least “see happening” on a moving coil meter, that are very hard to read on a digital. Examples might be voltage ripple (needle twitching), back EMF of a coil, the difference between a capacitor that’s failed open circuit and one that’s still capacitating away (Whether the value has drifted or not.)
Tomi Engdahl says:
The Worst Piece Of Test Equipment You’ve Got To Try Hacking
https://hackaday.com/2017/11/28/the-worst-piece-of-test-equipment-youve-got-to-try-hacking/
I have a fascination with the various online vendors of electronics and other manufactured goods from China. Here are listed the latest wonders from Shenzhen or wherever, which you can have for a surprisingly reasonable price, with the mild inconvenience of a three week wait for the postage.
So when I was shopping for a multimeter recently I took a quick look to see what the cheapest model from that particular supplier was. For somewhere around £2.50 or just over $3, I could have a little pocket analogue multimeter, the kind of “My first multimeter” that one might have found in the 1980s. They weren’t too bad, I thought, and ordered one for less than a pint of beer in a British pub.
What arrived was promising enough, in a plastic blister pack, the Sunma YX1000A.
Opening up the meter for a teardown, and I found a single printed circuit board, with as expected the selector switch formed by PCB pads. With the exception of a through-hole rectifier diode and trimmer used as the zero adjustment for the resistance ranges, all components were surface-mount.
There was no plating on the pads, save for the HASL or similar PCB tinning. Those pocket meters back in the day would usually fail because of oxidation of these contacts, no doubt this one would eventually succumb to the same fate.
The Sunma YX100A then: A case with a chip in it, a wildly oscillating meter mechanism that evidently has no damping, a stripe of grey paint for a parallax mirror, and a consistent 20% low reading. Even with a slightly tongue in cheek review, it’s fair to say that I have had better multimeters than the Sunma. In fact it’s fair to say that every multimeter I have ever used has been better than the Sunma. It’s possible that to make a multimeter worse than the Sunma would be extremely difficult, but they must have done it, because as they say, this is the “Improved Modeli”. Just how bad was the previous unimproved model?
Tomi Engdahl says:
10 Things You Must Know About Benchtop Digital Multimeters
https://www.electronicdesign.com/test-measurement/10-things-you-must-know-about-benchtop-digital-multimeters
So, you thought you knew everything about benchtop digital multimeters. Here are 10 things you may not be aware of, but are important factors in getting the most from your DMM.
Design engineers use digital multimeters (DMMs) almost every day. They’re the most commonly used instruments on any design engineer’s bench. A DMM could be utilized to make quick and simple voltage measurement or data log temperature measurements over time. Whatever the use, it must work.
The DMM is the workhorse of the engineering bench. In exchange for all of the work done by our DMM, we expect to do very little upkeep and maintenance in return.
1. Bench vs. Handheld
Though this article will primarily focus on benchtop DMMs and not handheld DMMs, do keep in mind that many of the topics and concepts apply to both platforms. In most cases, a typical benchtop DMM will have higher accuracy, better resolution, more sophisticated system programmability, and more advanced functionalities compared to a handheld DMM.
Connectivity is a big distinguishing factor between benchtop and handheld DMMs. Some handheld DMMs provide very simple USB or Bluetooth connectivity and mobile application. Benchtop DMMs typically offer more options in wired connectivity, such as LAN, USB, or GPIB, as well as software drivers. This allows for a sophisticated level of automated testing and software control.
2. Digits, Accuracy, Resolution
Different brands specify accuracy differently, though, so it can get complicated. The bottom line is that it ultimately translates into a range of possible returned measured values. Accuracy and resolution together give the user a big picture of the quality of measurements one can expect from a DMM.
3. Visualization
ome DMMs will returned digitized values over the communication ports, such as a LAN, USB, or GPIB, enabling the user to do post analysis on a separate platform like Excel. On a crowded bench, it’s critical to have a DMM that stands out and displays its measurements in a clear and easy to read manner.
4. Secondary Measurements
Traditionally, DMMs have been used primarily to take a single measurement. In some cases, however, we want the ability to see more than one type of reading.
5. Simple DC Power Measurements
Power measurements are critical in many test applications. For those without a power meter, the DMM has traditionally been the instrument of choice to make such measurements. A true power measurement requires both voltage and current to be measured simultaneously, since power is voltage multiplied by current.
While most DMMs can measure both voltage and current, they typically can’t measure both simultaneously. However, by using a few clever techniques, we can get around this issue and get a power measurement from a DMM. One such technique uses the math function.
The Keysight Truevolt DMM has a special feature to obtain simultaneous voltage and current readings.
6. Low-Current and Dynamic-Current Measurements
You need to be aware of the level of current-measurement accuracy needed for your measurement applications.
7. Measuring Difficult AC Signals
Usually, ac voltage signals are depicted in textbooks as perfect sinusoidal waveforms. In the real world, though, ac voltage signals and currents are far from perfect. They come in widely varying shapes and values. Digitizing a small portion of an AC waveform allows you to see a few short cycles. If you’re interested in RMS amplitude or frequency measurement over a long period of cycles, you will need to make ac measurements.
8. Temperature Variations and Auto Calibration
If you look at a DMM datasheet, you will normally find accuracy specifications change from the time of calibration (Fig. 4). The accuracy worsens as more time elapses from the time of calibration.
9. Triggering
Triggers allow you to start measurements based on the detection of a trigger source. Trigger sources include continuous, external triggers such as BNC or BUS; level triggers, based on the signal crossing a certain threshold; or exhibiting triggers, which have a positive/negative slope. In most advanced DMMs, you can program a trigger delay and capture multiple sample periods surrounding a trigger event.
10. 4-Wire Measurement
Generally, there’s resistance in the input leads of a DMM. This resistance causes a voltage drop and yields inaccuracies in measurements. The solution to this voltage-drop problem is 4-wire sensing. Perform your measurements right at the device under test, hence bypassing the voltage drop introduced by the input leads.
Tomi Engdahl says:
https://hackaday.com/2019/10/18/the-true-cost-of-multimeters/
Tomi Engdahl says:
https://www.petervis.com/meters/dt830d/dt830d-repair-and-fuse.html
https://marek.tukes.fi/Tuote.aspx?nettijulkaisuId=4323
Tomi Engdahl says:
EEVBlog $100 multimeter shootout
https://www.google.com/search?q=EEVBlog+%24100+multimeter+shootout&oq=EEVBlog++%24100+multimeter+shootout
Tomi Engdahl says:
DT830D Digital Multimeter
https://www.petervis.com/meters/dt830d/dt830d.html
Tomi Engdahl says:
The DT830 multimeter, then. It may be a heap of junk, but it’s an astonishingly good heap of junk. I for one, salute it.
https://hackaday.com/2020/09/24/in-praise-of-the-dt830-the-phenomenal-instrument-you-probably-dont-recognise-for-what-it-is/
Tomi Engdahl says:
Ode To An AVO 8 Multimeter
https://hackaday.com/2020/10/27/ode-to-an-avo-8-multimeter/
It’s a treasure from my youth, that most venerable of British test equipment: the AVO 8. This was the ubiquitous multimeter to be found in all manner of electrical and electronic workshops across most of the 20th century, and remains to this day one of the highest quality examples of its type.
It’s a relatively huge Bakelite box about 190mm x 170mm x 100mm in size, and it is instantly recognisable by its dual rotary selector switches and the window for viewing the needle, which forms a characteristic circular arc kidney shape.
The earliest ancestors of my meter appeared in the 1920s, and the first model 8 in the early 1950s.
A Very Different Approach To A Meter
To fully appreciate the AVO 8, it’s time for a teardown, for a glimpse both at how a very high quality analogue multimeter is built as well as how such things were designed at the dawn of the Jet Age. Dismantling it is very easy, a couple of screws allow removal of the battery compartment cover on the side above the meter, and six screws in the sides of the meter undo to allow the Bakelite tub to be eased away from the front face.
It’s first worth a quick peek in the battery compartment, where there would be two batteries for the various resistance ranges. One is the familiar D cell while the other is a BLR121, a curious 15 V pile of cells of the type once used in devices such as hearing aids and camera flashes. This cell is still available from specialist suppliers for AVO owners, but another option has been to incorporate a little switching regulator to generate the required potential.
Turning attention to the meter itself, and immediately we are in a world of electronics from another era. The meter movement has a full-scale deflection of 50 μA and us a significantly substantial affair whose magnet alone is larger than many modern panel meters in their entirety. The parallax mirror is a substantial piece of glass mirror fixed to the back of the scale — a nice touch.
The rotaty switches don’t use the tag-and-wiper method you might expect, instead relying on a set of springy copper finger contacts of the type you might see in older relays, that are pushed down by cams on the rear of the knob mechanism.
It’s clear then that the AVO remains an extremely high quality instrument, and is still a useful and accurate multimeter well into its sixth decade. I feel guilty then that I’ve neglected it in favour of a digital meter that cost an order of magnitude less. So why has it remained on the shelf then? An obvious answer might be that as an analogue meter its 20 kΩ/V sensitivity can’t match the high impedance of its digital rival, but that’s probably not the real reason. It’s seductive to carry a feather-light handheld unit rather than one the size of a medium-sized building block. That’s the real benefit of modernity: miniaturisation. I’ll try to use the AVO more on the bench because it’s a fantastic instrument. But will it regain its place as my main meter? Probably not. After all sometimes it’s better to stay in 2020 rather than 1950.
Tomi Engdahl says:
https://www.eevblog.com/forum/testgear/dual-impedance-multimeter-recommendations/
I need a meter with LoZ impedance, I have the 289, but I need another, my options are the Fluke 117 or GreenLee DM-830A. I know the greenlee is a brymen. I have another amprobe and keysigth meters, but the performance is not sorprendent like the my Flukes. For example my U1282A, the bar graph when I work with Ohms is more slow than my Flukes, the bar graph performance in the u1282a only detects clicks on 40 Hz update mode. My Fluke 87V even on hi-res mode the bar graph is fast. Really brymen meters are fast? the money difference between Fluke 117 and DM-830A is not important, but DM-830A it has a interesting LoZ mode, for example, the LoZ for Fluke is 3 kOhms, for keysight is 2 kOhms up to 600 V for both, the brymen change the input impedance from 3 kOhms to 460 kOhms for 1000 V, sounds good but, is functional? the brymen responce is really more fast to Fluke 117? Regards.
Tomi Engdahl says:
https://electronics.stackexchange.com/questions/145829/do-digital-multimeters-require-calibration
https://www.apesoftware.com/help/calibration-procedures/digital-multimeter
Tomi Engdahl says:
EEVblog 1378 – NEW Uni-T UT61E+ Multimeter – Still bang-per-buck king?
https://www.youtube.com/watch?v=ZxzQZFRznp0
Is the new Uni-T UT61E+ Multimeter still the bang-per-buck king the existing UT61-E was? How does it compare? Is the increased cost worth it?
FI
Haku
ut61e & ut61e+ bargraph speed
https://www.youtube.com/watch?v=usRES_RGK0Y
Tomi Engdahl says:
EEVblog 1379 – What’s all this NPLC Stuff Anyhow?
https://www.youtube.com/watch?v=yKb7xIsPjVM
Why does a handheld multimeter read zero volts and a bench meter reads several volts?
It’s all about the NPLC’s man…
Comment:
I love demoing this trickery to people however I usually take it a bit further and put my feet on a power board or hold a mains cable which capacitively couple huge amounts (for 10 MΩ) of signal onto a bench DMM or oscilloscope (sometimes 50+ V and enough to dimly light an LED), this way you can also demo how grounding yourself almost completely removes the signal and that those capacitively coupled ‘ghost’ voltages (especially those from isolated switching supplies) aren’t something to be afraid of (but might give you a small tingle).
Tomi Engdahl says:
EEVblog 1377 – The Amazing UNPREDICTABILITY of Fuses!
https://www.youtube.com/watch?v=WG11rVcMOnY
How long does it take for your 400mA multimeter fuse to blow at 600mA?
Grab a chair and watch!
The amazing unpredictability of fusing current ratings at low overloads.
Tomi Engdahl says:
EEVblog #1007 – Is a $25 Multimeter Any Good?
https://www.youtube.com/watch?v=xdGQEVdxmQQ
Dave looks at the $25 ANENG AN8008 Multimeter
It has some unusually low ranges making it ideal for electronics use. Or is it?
Tomi Engdahl says:
Top 10 Best Budget Multimeters 2021
https://multimetertools.com/best-budget-multimeters/
Tomi Engdahl says:
https://www.facebook.com/groups/electronichobycircuits/permalink/4645136918844314/
I recently received my order last week, as I got the Aneng9002 Bluetooth digital Multimeter. I have my reasons why I bought this model, as it feature Android interface. I reviewed the meter and you can check it out, if you wish to get one for yourself soon!
https://youtu.be/zc06Q_WR6ug
Tomi Engdahl says:
https://labprojectsbd.com/2021/07/29/5-coolest-multimeters-you-can-buy/
Tomi Engdahl says:
How to use your trashy meter without blowing it up (much)
https://www.youtube.com/watch?v=-QDW0LRQVrY
Your first multimeter can initially seem a bit daunting with all the modes, but the only way to learn is to get one and play with it. I damaged my first meter when I was young by using it on the incorrect range. You can damage these cheap meters, but at the cost you don’t have to worry about it too much.
I probably made this video too long and complicated, but it’s useful to know how things work as well as how to use them.
The very cheap meters sold for around 5 $/£/€ are usually pretty accurate for their cost and very usable. Once you’ve mastered using one you can move up to something with more features or more suitable for industrial work. These cheap meters are NOT suitable for poking around in distribution boards or industrial equipment with high fault current.
Meters have a category rating as follows:-
Cat I – electronic use (these cheap meters)
Cat II – electrical appliance, but not fixed wiring or distribution boards
Cat III – general electrical maintenance in panels and machines
Cat IV – utility level work with very high fault currents
For industrial work I recommend Fluke as it appeases the clipboard warriors. There are many other brands suited to industrial use too. Beware cheap meters with fake category ratings.
Tomi Engdahl says:
EEVblog 1424 – Fluke 23 Multimeter Repair
https://www.youtube.com/watch?v=-9kNSR4ozT4
Repair of an original Fluke 23 Multimeter.
Tomi Engdahl says:
The HP3458A: King Of Multimeters For Three Decades
https://hackaday.com/2021/10/18/the-hp3458a-king-of-multimeters-for-three-decades/
[Marco] looks at a lot of meters. However, he considers the HP3458A the best even though they were introduced more than 30 years earlier in 1989. Someone donated one to [Marco] but it presented some error messages on startup and exhibited erratic behavior, so he had some repairs to do.
The error codes hinted there were issues with the multislope analog to digital converter and that’s what sets the meter apart, according to [Marco]. The meter has 8.5 digits, so a normal conversion stage won’t cut it.
HP 3458A – Why is this 31 year old Multimeter UNRIVALLED?
https://www.youtube.com/watch?v=upTgM_S5rAQ
Tomi Engdahl says:
https://hackaday.com/2021/12/07/multimeters-go-big-screen/
Tomi Engdahl says:
eevBLAB 91 – Why Are Fluke Meters So EXPENSIVE?
https://www.youtube.com/watch?v=ay9wFQAW19Y
8 industry reasons why Fluke meters are so expensive, and why people still buy them.
You might be surprised by some of the reasons and have not encountered this thinking before in the industry.
Tomi Engdahl says:
EEVblog 1378 – NEW Uni-T UT61E+ Multimeter – Still bang-per-buck king?
https://www.youtube.com/watch?v=ZxzQZFRznp0
Is the new Uni-T UT61E+ Multimeter still the bang-per-buck king the existing UT61-E was? How does it compare? Is the increased cost worth it?
00:00 – Old UT61E
09:18 – NCV test
10:33 – Probes and Continuity
15:57 – Teardown
25:26 – Specs
26:15 – Conclusion
Tomi Engdahl says:
Useful looking probe hack that uses magnet to stick to the circuit metal ground parts:
How to Make a useful tool To make the multimeter easy to use
https://www.youtube.com/watch?v=Ti2fH0wwvdY
Hello Geniuses in this video i’m gonna show you How to Make a useful tool , You Can Make At Home its very Simple
Tomi Engdahl says:
Adam Savage’s Favorite Tools: Best Budget Multimeter!
https://www.youtube.com/watch?v=K9fQn1bQVsQ
An essential tool for a modern propmaker is a multimeter for any kind of electronics work, whether for testing lighting circuits or troubleshooting wiring work. And while Adam has relied on his trusty Fluke 77 multimeter for years, getting an electronics multimeter to start your toolkit can be affordable too. That’s why he’s a fan of Fluke’s compact entry-level multimeter, which costs less than $45 and gets the job done!
Tomi Engdahl says:
Why is There a Frequency / Wave Symbol on Multimeter?
Link of Video : https://youtu.be/C3EKI83NaPo
We have seen a Frequency/Square Wave Symbol in the Yellow multimeters. But many of us do not know what it actually does. In dotays video I have explained it with practical demo.
Tomi Engdahl says:
Adam Savage’s Favorite Tools: Best Budget Multimeter!
https://www.youtube.com/watch?v=K9fQn1bQVsQ
$44 Fluke 101 Multimeter
Fluke 77 Multimeter
Tomi Engdahl says:
Review: Mid Range / Priced Multimeter Shootout / Buyers Guide
https://www.youtube.com/watch?v=wRd2fX_1318
Multimeter buyers guide / review / shootout: UNI-T UT61E vs Brymen TBM251 / BM251 vs Fluke 17B vs Agilent U1232A vs Fluke115
EEVblog #432 – Brymen Multimeters
https://www.youtube.com/watch?v=tXu0lsOjvDs
Dave takes a quick look at three Brymen Multimeters.
Tomi Engdahl says:
EEVblog 1447 – EXPENSIVE Fluke vs CHEAPER Brymen – Teardown
https://www.youtube.com/watch?v=3Hlmq57FQQk
Why are Fluke multimeters so expensive? PART 2
A teardown of the Fluke 70/170 series vs the Brymen BM786. Is there any design and construction difference that justifies 2-3 times the price?
00:00 – Fluke vs Brymen
01:07 – The Yellow Peer Pressure
01:57 – Fluke 77/177 vs Brymen BM786
04:01 – Ruggedness
05:05 – Plastics
06:11 – Teardown & A Tip to screw your meter
11:09 – Input protection
14:36 – LCD Connection
16:45 – Input Protection
19:20 – Hybrid resistor divider
20:47 – Processor and Chipset
22:27 – Arguably a tighter and more expensive BOM
23:39 – Range Switch
26:53 – Buzzer & Shielding
27:46 – Conclusion
eevBLAB 91 – Why Are Fluke Meters So EXPENSIVE?
https://www.youtube.com/watch?v=ay9wFQAW19Y&t=0s
Tomi Engdahl says:
EEVblog #376 – Multimeter Fuse Diode Followup
https://www.youtube.com/watch?v=ne_Prn0eGQE
How diode bridge protection across a shunt resistor in a multimeter works, and why the fuse blows before the diode does on a well designed multimeter like the Fluke.
A followup to the previous video on Multimeter input protection:
https://www.youtube.com/watch?v=zUhnGp5vh60&t=0s
Tomi Engdahl says:
EEVblog 1448 – Convert a Fluke 77 IV to True RMS for 10 CENTS!
https://www.youtube.com/watch?v=X_1M3xgl4zo
How to convert a Fluke 77 IV average responding multimeter into a True RMS model 177 for 10 cents.
Should also work for converting a Fluke 83V to 87V
True RMS measurement vs Average Responding
And calibration of a Fluke meter.
00:00 – Hacking a Fluke 77 IV Multimeter
00:35 – Is the Fluke 70 series discontinued?
01:15 – Fluke History
03:10 – I noticed something…
04:49 – The AD737 True RMS converter chip
06:04 – Theory of Operation
07:21 – What is Crest factor
08:58 – How do they do it?
09:25 – Fluke 87V Schematic and the custom ASIC
10:53 – Let’s modify it!
12:58 – A sine wave is NOT a crest factor of 1
14:01 – Soldering
15:15 – Will it work?
16:46 – Calibration procedure
20:09 – Winner Winner Chicken Dinner
Fluke 87V service manual with schematic:
https://xdevs.com/doc/Fluke/87V/Fluke_87V_Full_service_manual_with_schematic_and_electrical_parts_list_Service_Manual-87VANFullService.pdf
Tomi Engdahl says:
How to turn any Old multimeter to multimeter supports NCV ( Non-Contact Voltage )
https://www.youtube.com/watch?v=9u1aKVqRDGg
Hello Geniuses in this video i’m gonna show you How to turn any Old multimeter to multimeter supports NCV , You Can Make At Home its very Simple
Great – just hold your DMM’s negative lead close to some power wire, it will do the same thing.
Therefore, this comes included with every DMM free of charge – no wire dingus necessary!
Tomi Engdahl says:
What’s the Difference Between Analog and Digital Multimeters?
Jan. 26, 2022
Digital meters are generally more widely used, but there are times when analog is the way to go, and hybrids can provide a “best of both worlds” option.
https://www.electronicdesign.com/technologies/test-measurement/article/21215098/simpson-electric-company-whats-the-difference-between-analog-and-digital-multimeters?utm_source=EG%20ED%20Analog%20%26%20Power%20Source&utm_medium=email&utm_campaign=CPS220124016&o_eid=7211D2691390C9R&rdx.ident%5Bpull%5D=omeda%7C7211D2691390C9R&oly_enc_id=7211D2691390C9R
Tomi Engdahl says:
Tiny $2 Multimeter with 1000V Range! Test with Smoke
https://www.youtube.com/watch?v=AK02JakVVPY
Testing a tiny Chinese $2.20 analog multimeter with 1000V AC / DC range. This little thing has very small probes, thin cables and loose plugs. There are tiny SMD resistors in it, about 0.6mm spacing between PCB tracks and no fuse! And this has to handle 1000V AC / DC. The scale and the screws are rusty and the battery doesn’t fit into it properly. I also have an older version of it (about 15 years old). The only difference is that the old version had THT resistors, the new one has SMD ones (and this makes it even worse). If you really want to use such multimeter, use it only for safe voltages and low currents.
Awesome smoke test. Dangerous small SMD resistor for the 1 kV range. and very close CCT board tracks. Keep up the good work.
Tomi Engdahl says:
Dangerous Multimeters (+ Explosion, Smoke & Fire)
https://www.youtube.com/watch?v=AjtoIRclid8
Sharing my explosive experiences with dangerous multimeters and recreating the explosion of the probe that originally exploded inside my hand. Some multimeters can’t handle mains voltage on some ranges, despite the manual claims they should. They often claim maximal voltage to be 500 to 1000V, despite the fuse is rated only 250V. The cables have very thin copper core, despite being rated 10 or even 20A. In use, they get very hot. As the cables of the multimeter are frequently used and are exposed to bending, the copper core slowly breaks, until just few hairs remain. This mostly happens where the cable leaves the probe. Then you measure a high current (like 10A) and the cable just EXPLODES!!! This is exactly what happened to me while measuring the current of a 230V 10A load. The multimeter probe exploded in my hand and miraculously only burned me but it didn’t electrocute me.
Viewer comments:
Yes, test probes are something that’s often overlooked.
As an electrician in the UK, i’m often measuring the Ze value (what most sensible people would call the earth fault impedance). Basically it involves sticking probes on the main intake cables which in the UK are fused at between 60 and 100 amps, and connected to a very low impedance supply (short circuit values up to 16,000 amps, altho that’s quite rare. But I routinely see 2-3000 amps as a value).
Imagine your scenario there, combined with a short in the meter… doesn’t bear thinking about.
My colleague thinks I am mad for constantly checking the probe wiring, and wearing full protective gear (insulating gloves with protectors, face shield, ear defenders etc).
I’d rather look stupid and be alive than look cool at my funeral
After high voltage involved fatal accident you must likely will be buried in closed casket. Without opening in funeral to not disturb people.
Huh, that’s pretty cool. A multi meter that tracks power, and has a built in fire starter!
I got some 5€ multimeter from gearbest some time ago and it has worked fine. One issue is that the probes have no strain relief so I broke one of the probes because the copper wire came out of the tip. Once I fixed that and added a form of strain relief on the probes it has been okay, but I would never stick it into mains and I doubt I will work with that kind of stuff any time soon so I don’t really need a better meter for higher voltages because I don’t use high voltage
Most multiple meters with transistor tester on front are dodgy for mains and higher voltage/current testing!
I tried measuring my power outlet but my multimeter setting was 600v DC 10A. So it exploded twice before my eyes. It was a near death experience
The frequency measurement thing is basically the same on all chinese multimeters but mine (aneng 8008) has mentioned in the manual that Hz is for low voltages, thankfully i didnt plug it in the mains or i would have burnt it..
Never trust any rating you can’t check yourself either via careful testing or a UL report or similar; your life is worth too much to trust random ebay sellers when they make safety claims with their $10 meters. Good info on making sure you understand how your own equipment works and how important good probes are. I myself had a couple of cheap meters when I started in electronics that were actually quite good… but I threw away the crap probes that came with them and got some really thick and well made ones instead. Lasted me for years…
“You never know how well [your equipment] is made” — errrr… this is precisely the reason people pay a substantial premium for Fluke meters and other quality probes, bought from reliable vendors so you know they’re not fake. You aren’t paying for features, you’re paying for trust.
I don’t cheap out on anything attached to mains Voltage. Cheap Meters are fine if you stick to low Voltage+Current applications, but don’t bet your life on the fake CAT rating or protection Circuits of cheap Meters.
If its potentially dangerous, get a proper, certified Meter.
the cat rating and how much you can trust the brand are what tells you how badly it detonates if you stick it across 400V in the wrong setting
The meters explode, because people don’t know what socket to put the test leads in for the different functions. I am guilty of this as well and had sparks. So I purchased a smart DVOM that lights the socket for the range chosen. It is a great idea, but only expensive ones seem to have this function.
Rule #1: don’t trust cheap chinese MM for mains… Only use a known brand from a known local seller. How much is your life worth?
Tomi Engdahl says:
4 Basic Electrical Testers & HOW TO USE THEM
https://www.youtube.com/watch?v=ZfWDESUEfmA
There are 4 basic types of electrical testers that every electrician needs to know how to use, in this video we’re going to cover what they are, and how to use them.
Tomi Engdahl says:
https://hackaday.com/2022/02/07/fluke-dmm-hack-adds-one-digit-to-model-number/
Tomi Engdahl says:
EEVblog #1067 – Analog vs Digital Multimeters!
https://www.youtube.com/watch?v=HHALK0sv1Y0
Are analog multimeters still of any practical value compared to digital?
Only Dave can ponder that question for a half hour video…
https://www.eevblog.com/forum/blog/eevblog-1067-analog-vs-digital-multimeters/
Tomi Engdahl says:
Turvallisuusilmoitus: Fluke 8X V -sarjan digitaalinen yleismittari
Arvoisa Fluken asiakas
https://www.fluke.com/fi-fi/tuotetuki/turvallisuusilmoitukset/8x-v-turvallisuusilmoitus
Fluke Corporation on havainnut mahdollisen turvallisuusongelman, joka koskee tiettyjä digitaalisia Fluke 83V-, 87V- ja 88V -yleismittareita (Fluke 8x V -sarjan digitaaliset yleismittarit).
Tomi Engdahl says:
Classic Multimeter Tells You If Your WiFi’s Working
https://hackaday.com/2022/02/22/classic-multimeter-tells-you-if-your-wifis-working/
Simpson Meter Provides Internet Status
https://www.youtube.com/watch?v=Wpw3AmSZErc&t=1s
Tomi Engdahl says:
EEVblog 1465 – Your Multimeter Can Measure Inductors
https://www.youtube.com/watch?v=UrS5ezesA9s
Handy tip on how you can use your multimeters capacitance range to measure inductors, using the reciprocal method.
Tomi Engdahl says:
Detailed Big Screen Multimeter Review
https://hackaday.com/2022/04/04/detailed-big-screen-multimeter-review/
It seems like large-screen cheap meters are really catching on. [TheHWcave] does a very detailed review of a KAIWEETS KM601, which is exactly the same as a few dozen other Chinese brands you can get from the usual sources.
#109 How good is the KAIWEETS KM601 Smart Digital Multimeter?
https://www.youtube.com/watch?v=2XAa2By9Xg8
Tomi Engdahl says:
EEVblog 1392 – No temp probe? No problem!
https://www.youtube.com/watch?v=57VuCgb6Udw
Think your multimeter doesn’t have inbuilt temperature measurement? Think again!
Dave shows you a trick to measure ambient temperature with your multimeter without a temperature probe.
Tomi Engdahl says:
ABCs of multimeter safety: Multimeter safety and you
https://electricalapprentice.co.uk/abcs-of-multimeter-safety-multimeter-safety-and-you/
Where safety is a concern, choosing a multimeter is like choosing a motorcycle helmet—if you value your head, get a safe helmet. The hazards of motorcycle riding are obvious, but what about multimeters? As long as you choose a multimeter with a high enough voltage rating, aren’t you safe? Voltage is voltage, isn’t it? Not exactly.
Tomi Engdahl says:
Multimeter probe safe use and safety features
https://www.youtube.com/watch?v=CXibZ0HEwWk
A little chat about Multimeter probe safe use
Excellent safety tutorial.
It is great to see the industry becoming more safety conscious about their equipment and test leads.
Many cheap knock off meters that are highly dangerous and are potential killers.
Tomi Engdahl says:
Can you hurt yourself with a multimeter?
Shock hazards can occur if the meter and test leads are not properly maintained. Arc flash can occur if the meter is not properly rated for the voltage, the meter is exposed to transient voltages outside of its operating conditions, or because of defective parts or components.
The Dangers of Digital Multimeters (2021)
https://leafelectricalsafety.com/blog/digital-multimeter-danger
Voltage transients are just a fancy term for voltage spikes.
Occasionally the voltage on a 480-volt system can find itself all the way up to 8000-10,000 volts!
Often, within a plant, these overvoltages can be generated by motors, capacitors, and variable speed drives.
Lighting strikes on outdoor transmission lines is also a highly probable cause for a voltage transient.
This is why it’s so important to make sure you have purchased a digital multimeter with the proper category rating for the work you are performing.
SOLUTION: CHOOSING THE CORRECT METER AND PROBES
There are two major factors in choosing the correct meter for the job, voltage level and category rating. This goes for the test probes being used as well.
The voltage level is straightforward.
Do not use a meter/probes rated less than the voltage of the equipment being tested.
The meter/probes can explode and cause an arc flash.
Category rating refers to the magnitude of transient overvoltages (described above) that the meter/probes can withstand.
Proper category rating is based primarily on the location of the equipment in proximity to the source (as transients will be minimized as system impedance increases).
Typically, the closer to outside the higher the category rating required.
CAT II Single phase receptacle connected loads;
CAT III Three-phase distribution, including single-phase commercial lighting;
CAT IV Three-phase at utility connection, any outdoor conductors.
Tomi Engdahl says:
https://leafelectricalsafety.com/blog/digital-multimeter-danger
Comment from Greg at ABB: “This is a very good post, but I must disagree with your promotion of using a multi-meter to verify the absence of operating voltage. This is due to the very reasons you have outlined in the post. We require the use of a voltage detection device that is properly rated, inspected by the qualified user pre-use, and functionally testing the device prior to and after verifying the absence of voltage via a proving unit. We use these devices when verifying the absence of voltage when placing LV (≤1kV) electrical installations and apparatuses in an electrically safe working condition.
In a very large multinational company, this has been challenging to implement, but I believe that we are heading in the right direction. Once again, this is an excellent post regarding risks of the use of digital multi-meter as we still rely on them to measure voltage levels in many applications and resistance in electrical circuits. Thank you.”
I must admit I was then really caught by surprise that you conclude with «they must be used to determine the absence of voltage». This comment alone is incredibly dangerous. There are far more effective and safer devices which should be used over a multi-meter to prove the absence of voltage. We call them «test lamps» in Australia, though Google Fluke T110 to understand the device I am referring to
Many years ago in ABB we prohibited multi-meters being used as a verification of absence of voltage. In place we provided the alternative of using properly rated test lamps along with a voltage proving unit to further reduce the risk to the operator.
Tomi Engdahl says:
What is the safety precaution in using multimeter?
What are multimeter safety precautions? Before you take a measurement with your multimeter, you should visually inspect it first. Check the meter, test probes and accessories over for signs of physical damage. Make sure all plugs fit securely and keep an eye out for exposed metal or any cracks in the casing.
https://www.fluke.com/en/learn/blog/safety/multimeter-guide