EEVblog #252 - Multimeter Ohms Overload

Is the Agilent meter alone in slow recovery from mains overloading on the ohms range? Let's find out...

[ricardomenzer]

When I got my first multimeter (back when I was about 9 yo), the first thing I did was to measure the mains voltage. Happy to see the nominal 127V, I decided to measure the mains current.

Yep, had to buy new tips the next day.

Never thought to measure the mains resistance though! ;)

[johncunningham]

Incredible, how the fluke meter recovered. It would be interesting to see the differences in each meter teardown the applications used for input protection.

[SigEpBlue]

Excellent job here. You're awesome for following up on previous videos where there might be questions about certain things. Thanks for all the hard work & dedication you put into these vids!

I was really hoping for some magic smoke from the Vichy. I ought to send you one of the miniature analog Wal-Mart meters they sell for about $9; I'm almost certain it wouldn't survive.

[TheNicholasBrothers]

If this video taught me anything, it's that you can never, ever, ever have "too many" multimeters.

[MistahHeffo]

I can see Agilent now, working on a meter that not only maintains accuracy after taking mains in the ohms range, but also gives you a valid ohms reading of the parallel resistance of all the mains transformers connected to that circuit

[superdau]

Thanks for testing the VC99, too, so I don't have to. I actually bought it after I saw your shootout, because I thought it performed very well in that. Didn't perform bad this time either IMHO (resistance measurement was spot on). It may be cheap chinese but it's not bad for the price. Had no problems with it at all in almost a year. And due to the US dollar being worth shit at the time I bought it in Euro, I'd say it was a bargain.

[eurokid]

@SampsonGizmo Because it's very likely that someone will accidentally apply voltage to the meter on the ohms or diode check function. This is a "test" of how well / if the meter will recover.

[agmadsag]

Thanks for your videos Dave, I'm very happy for my BK precision!

[magicphysicsdude]

So THAT'S why some multimeters cost several hundred dollars (and are not a rip off). I guess they really are super awesome quality.

I wonder what would happen if you used an even cheaper multimeter than the ebay one you used. One of those multimeters you can get for $5.

[CampKohler]

I'm used to the old meters that would smoke instantly on 120VAC, much less 240VAC.. Barbecue's your uncle!

[nickhubble]

I would really enjoy a Fluke series test much like this one. as to see the engineering differance ' s. I have a Fluke 179 and I'm wondering if it has the same failsafe as the mighty 87v.

cheers.

[Monkeh]

@hitachi088 Because blowing up fuses and possibly meters is a really worthwhile use of his time.

[monchiabbad]

Is any one of those meters good enough that while being overloaded it actually measures the resistance of the circuit they are being overloaded on ?



:-P

[Monkeh]

@hitachi088 I know that's what fuses are for. Showing how easily a fuse blows when you put several kiloamps of fault current through it is not overly exciting. It would be interesting to see how many of the cheaper meters continue to function afterwards, but not worth the possible destruction of them.

[pikuorguk]

I've got one of the Extech meters. I also now have a supply of 10a fuses after probing a car battery while in continuity mode ;-)

[SaderStel]

Dave I really like your multimeter reviews, but I never saw Mastech brand reviews, they are main go in my country, would be great if you could take a look at them, myself using MY68 :]

[ncrdisabled]

What is that gsm fix you talked about for a Fluke meter . Which meters did it affect and what did it fix in the fluke meters . I have several flukes from over the years from when I was in the NAVY on Submarines to when I worked as a electronic tech for ASI company working on Delorean radios .

[ElectroElvisBlog]

Dont know if this has an impact to the accurate measuring but when you sticked mains to the second Gossen meter battery signt went from 1 bar to 0 bar and when conecting to precise box again it returned you 1 bar back.

[envisionelec]

I would have put the meter behind a sheet of lexan (perspex). You're braver than I.

[gorillaau]

@SampsonGizmo I belive that the purpose of the test is to see if the meter allows for human meter. Decent meters should be tolerant of the occasional whoops like that.

But don't try it with a $10 bargain bin special as I'd expect them to go bang in some fashion. I wouldn't want to try it. :-)