Author Topic: Why do I need more than 1 multimeter?  (Read 7468 times)

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Offline sleemanj

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Re: Why do I need more than 1 multimeter?
« Reply #50 on: July 27, 2019, 10:04:47 am »
Cheap multimeters are so capable these days with 6000 or even higher count meters for less than $20 USD that you're crazy not to have at least 2, preferably at least 4 so you can do input and output measurement of both voltage and current simultaneously.

Get "a good one" if you want, but for the majority of people "4 cheap ones" is better than "1 good one" if you ask me.

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Offline TheAmmoniacal

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Re: Why do I need more than 1 multimeter?
« Reply #51 on: July 27, 2019, 10:06:37 am »
Problem is, you can only know what the real voltage is if you only have one meter. If you have many meters you can never be sure!
 

Offline bd139

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Re: Why do I need more than 1 multimeter?
« Reply #52 on: July 27, 2019, 10:12:44 am »
If you have lots of good Flukes you can be sure. These two are 20 years apart. Left one cal 2018. Right one cal never!



Sometimes they all agree!



 >:D
 

Offline Rick Law

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Re: Why do I need more than 1 multimeter?
« Reply #53 on: July 27, 2019, 05:49:06 pm »
Problem is, you can only know what the real voltage is if you only have one meter. If you have many meters you can never be sure!

You can never know the "real" voltage.  You can only know it to within a range.  With only one meter, you know only the assumed value and the assumed nominal range.  The assumption is that your meter is working and in spec.  I am sure all of us at one time or an other damaged our tools before.  So that assumption is an iffy one.

With two meters, you can test that assumption, make the error range shorter, as well as increase that confidence.  With many meters, you can do statistical analysis to get to an even narrower range of probable error.  But, you can never get to zero error.

When I was college age, I would probably say DMM's are like girl friends, the more the better.  But that view would of course be very politically incorrect today...
 

Offline Electro Detective

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Re: Why do I need more than 1 multimeter?
« Reply #54 on: July 27, 2019, 11:00:29 pm »
This thread is amusing. For me:

Multiple multimeters: measuring so many things at once. I had 5 on a test rig the other day. One measuring input current. Two measuring output voltage. Two measuring output current. Then I needed to test a bias point on the circuit  >:( ... plus they look nice all lined up like an army.

Multiple oscilloscopes: Bar the exceptional case with BravoV above with a lot of very nice newish scopes, this happens for most people when they have old analogue scopes. It starts of as an "oh I need a scope and that one is cheap". However the things are so bloody unreliable even if there are romantic aspirations about how excellent they are. So you buy one scope, fix it. Works! Woohoo. Then you find out there's a dodgy switch or the HT gives out right in the middle of something. Then you find out you can't get parts for it any more apart from some guy half way across Europe who has a stash of rare parts which cost you a kidney. So you're at a hamfest and you see another one for a reasonable price which you hope will live up to your expectations. "Yeah of course it works mate" says the guy taking your cash. Get home and it does work. Apart from one minor function you are going to need. So you then have two scopes and cannibalise one to fix the other. Then an attenuator packs in or you find it won't cal and the process starts again. After a few months you turn into me who has had 44 oscilloscopes in the last 20 years, 35 of them in the last three years. Then there's a sudden click in your mind, you sell all the damn things vowing never to touch an analogue again so you buy a Rigol because it at least mostly works. Plus you made a ton of cash selling all those scopes off to people after that hell you just went through. Life is good. For a while. Then you realise you need X-Y mode and the Rigol one sucks balls. So you look on gumtree and find a cheap analogue crate just for X-Y. Then you remember how fond you were of a user interface that isn't buried in menus. Then the analogue fear of failure kicks in and you start stuffing them on the watch list on ebay.  :scared:

I haven't worked out if this is a mental illness or not yet.

Now multiple power supplies ... that's another one. I've got 4 supplies with 7 outputs and several little meanwell switchers and it's never enough.



OCD affected serial naggers may call it 'hoarding'    :blah:  :blah:

but whatever it is, rest assured YOU ARE NOT ALONE !   :scared:


fwiw: I reckon it's the easy access of finding wish/want gear on the internet and getting it shipped asap

and yeah, having to fix gear that one needs to use to fix gear can be a pain, and easier to just get another in the meantime,

and then finding time to fix all the broken ones in one hit, source parts etc (wishful thinking on sourcing 'finding time' parts)


Then there's the trap of casual surfing on Ebay and other sites to 'see what's around' and 'what ones gear is worth to sell off'  :-//

and then you spot something with low bids or no bids, local pickup..mint condition  :o

and well, need I continue.. ?     :-[  :palm:




 
 

Online Nominal Animal

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Re: Why do I need more than 1 multimeter?
« Reply #55 on: July 28, 2019, 12:27:48 am »
It aint hoarding if you use them tools. :-DMM
 

Offline Berni

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Re: Why do I need more than 1 multimeter?
« Reply #56 on: July 29, 2019, 07:09:20 am »
Well id say collecting test equipment is still a better hobby than collecting most other things like stamps or baseball cards.

The resulting pile of equipment does come useful every so often even if the piece of specialty gear in question was not powered on for the last year or two. Also the process of it is pretty exiting as you celebrate a little inside every time you score a piece of gear for a great bargain price, then comes the tense wait for it to get here as you have second thoughts about how hard it might be to fix. Then the thing finally arrives, taking it apart and looking at whats in there and how it works, sometimes getting everything apart and back together is a bit of a mini puzzle. Sometimes it just needs a new fuse, other times its an adventure of tracking for the spare parts. And then it finally WORKS again and its a great sense of accomplishment. You proudly clean it to make it look as new as possible, give it any missing feet and put it up on a shelf.

There is also plenty of progression since quite a lot of times you need other gear to fix or calibrate whatever you bought so you have to gradually bootstrap yourself up the chain, giving you a nice sense of progress trough it all. And it doesn't stop once you have every major category of instrument, there is always an instrument out there with more performance than what you got, so it also becomes a matter of upgrading your gear collection to reach new heights of GHz,TOhms, nV, pA etc....

Tho if you are going for a collection of gear similar that of the TheSignalPath youtube channel then you will need some pretty deep pockets.
 
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