Author Topic: Why do I need more than 1 multimeter?  (Read 7473 times)

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Offline Brumby

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Re: Why do I need more than 1 multimeter?
« Reply #25 on: July 23, 2019, 12:34:25 pm »
... And this is how volt nuttery starts.

Starts - and continues .... (and, no, it never ends.)
 
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Offline Rick Law

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Re: Why do I need more than 1 multimeter?
« Reply #26 on: July 23, 2019, 05:58:33 pm »
Well there is still a benefit to having only 1 multimeter. When you measure something being 10V you accept it as being 10V

If you have 2 multimeters and one shows 10V and other shows 9.998V... so which meter is accurate. Now you need a 3rd one to check, but then that meter shows 9.999V. And this is how volt nuttery starts.

With that logic, why not have none?  You just estimate and you can't be proven wrong.

Three.  That is my magic number.   Normally, I measure with my lone "good one" (UT61E).  The other two are cheap DT820's.  They are generally for when I work with power related.  In those cases, I like to know Vin-Vout, or V & I at the same time.  I also have a few ADS1115 boards (16 bit DAC) along with a few INA219 boards (12 bit DAC) that can be hooked up quickly to take on the V&I measurements.

As to volt-nuts...  I think I recovered from it.  I came to accept - well, until I get a 64 kilo-bit DAC with +-1% accuracy, I would not be truly happy with the results.  But some old German guy call Heisenberg or something like that - this fellow poured cold water on the idea of really really really accurate measurements...
« Last Edit: July 23, 2019, 06:00:46 pm by Rick Law »
 

Online mariush

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Re: Why do I need more than 1 multimeter?
« Reply #27 on: July 23, 2019, 06:14:34 pm »
It's good to have at least two multimeters, for example to measure input and output voltages , or to measure current while also measuring voltage.

You could also have two multimeters for various functionality you might need.

For example, my main multimeter is a Uni-T UT61E. However, I also bought a Uni-T clampmeter, to measure AC and DC currents without breaking the wires that power devices. As a side functionality, it's also a 2000 count multimeter capable of measuring voltage, resistance, continuity... and it's good enough for some basic measurements.
Then, I also bought a LCR meter, because I wanted to have something capable of measuring inductors... and this one can also measure voltages and resistors and so on...
 

Offline mindcrime

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Re: Why do I need more than 1 multimeter?
« Reply #28 on: July 24, 2019, 02:04:47 am »
The correct number of multi-meters to own is always n+1, where n is the number you currently own...

For more quality advice, visit the TEA thread...  :-+

Additionally, in the first sentence above, you can replace "multi-meters" with any of ( oscilloscopes | power supplies | LCR meters | spectrum analyzers | logic analyzers | signal generators | rubidium standards | network protocol analyzers | data acquisition mainframes | pulse generators | insulation testers | modulation domain analyzers | etc) and it remains equally true.  >:D
« Last Edit: July 24, 2019, 02:07:45 am by mindcrime »
 
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Offline Brumby

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Re: Why do I need more than 1 multimeter?
« Reply #29 on: July 24, 2019, 03:30:45 am »
The correct number of multi-meters to own is always n+1, where n is the number you currently own...

I would like to challenge that.  My current status is at n+2.

In addition to my current holding, I would like to add a bench meter with 4 wire measurement and something like the Uni-T 210E for a DC current clamp meter.  Why? ... Because I don't have them.   ;D
 

Offline vinlove

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Re: Why do I need more than 1 multimeter?
« Reply #30 on: July 24, 2019, 01:01:55 pm »
When measuring a component, if reading is out of expected value, then I wonder, if it s it the component or MM.  Then I want to try with as many MMs as possible to confirm which is at fault. More MMs, merrier the confirmation.
« Last Edit: July 24, 2019, 01:05:09 pm by vinlove »
 

Offline Cliff Matthews

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Re: Why do I need more than 1 multimeter?
« Reply #31 on: July 24, 2019, 03:46:00 pm »
Some situations could require 5 DMM's and perhaps a webcam to record simultaneous event data. More never hurts (unless your significant other knows how to drop-kick..)
 

Offline Berni

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Re: Why do I need more than 1 multimeter?
« Reply #32 on: July 25, 2019, 05:59:13 am »
While i do probably have too many multimeters i do agree that the actual useful benefit of having more does tend to fall off after the 3rd one.

Having 3 of them lets you notice if 1 of them is going out of calibration because you will see 2 meters agreeing and one disagreeing.

Also 3 meters is the minimum for reasonably measuring the efficiency of a power supply. You need 2 meters to be current meters on the input and output. Those can't be be easily disconnected and moved around because moving the probes away breaks the circuit, while shorting the circuit back together affects measurement because the meter was causing a voltage drop different to the short. But the voltage can be a single meter since you can just poke the input and then poke the output with the probes without affecting anything.

But there still are reasons to go to >3 multimeters. Like measuring power supply efficiency without having to move a multimeter around, or having multimeters with extra special features for a given task. Like able to measure very small voltages or currents, having lots of digits (like 6.5 or more), having high impedance inputs, having a really nice continuity beeper in it, being small and rugged for field use... etc. You can't get all of these features in one meter
 
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Offline SparkyFX

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Re: Why do I need more than 1 multimeter?
« Reply #33 on: July 25, 2019, 08:03:04 pm »
Only one meter ???????

Are you sure you belong on this site ?     :)
I thought two are minimum for signup on the forum....
Support your local planet.
 
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Offline windsmurf

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Re: Why do I need more than 1 multimeter?
« Reply #34 on: July 25, 2019, 08:31:56 pm »
I agree multiple meters are useful to measure voltage and current simultaneously. 

So why can't they build a meter that can do both at the same time?   

And why would anyone need more than 1 scope?  >:D

 
 
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Offline vinlove

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Re: Why do I need more than 1 multimeter?
« Reply #35 on: July 25, 2019, 09:13:39 pm »
I agree multiple meters are useful to measure voltage and current simultaneously. 

So why can't they build a meter that can do both at the same time?   

And why would anyone need more than 1 scope?  >:D

Because using several MMs are good fun, and feel great. You can also compare readings of different MMs for the same component. :D

And not all MMs have all the capabilities in one. Some MM do not have capacitance, some dont have NCV, some dont have hFE ... some MMs have Capacitance reading limitation to 1000 nF ..... blah blah.

Having more than 1 scope gives more flexibility. I have 1 base scope, and 3x portable ones. I carry the portable ones to the shed, car and out in other locations in my pocket or bag.  Cannot do that with 1 desktop scope powered by mains.
 

Offline Electro Detective

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Re: Why do I need more than 1 multimeter?
« Reply #36 on: July 26, 2019, 12:02:31 am »

All the above reasons, and MORE* coming     (*meter/s in your 'posession')
and do you really need another phone or the latest shiny adware magnet one? Meters are more fun, survive drops better and no Facebook BS

My two probes worth: different meters sport different features, Min Max and Low-Z and Auto Low-Z I find very useful in many iffy situations,
basic logging is nice too, to keep unattended tabs on a tedious or intermittent head banger,  |O

I find owning a 'few' meters (nose growing..  :o) with ALL the various functions scattered amongst them,
is a cheaper and better bet, than having one or two expensive 'all in ones', sometimes with too much smarts on board   ::)
and not really the 'jack of all trades' you think you have   


and here's an important FYI for the pocket > some cheaper decent meters excel at being sacrificial,
i.e. they just won't spark out or die like expensive ones tend to sometimes do

I think three multimeters plus a clamp meter is a good minimum to have, and cut off point (good luck with that..)
Upon getting there, the meters photographed with the owner in a mug shot holding up today's newspaper,
then emailed to EEVblog Admin as a requirement to join the forum  ;D


 
 

The correct number of multi-meters to own is always n+1, where n is the number you currently own...

I would like to challenge that.  My current status is at n+2.

In addition to my current holding, I would like to add a bench meter with 4 wire measurement and something like the Uni-T 210E for a DC current clamp meter.  Why? ... Because I don't have them.   ;D


I keep meaning to get one every few months when I remember or see posts here about it, for those iffy AC and DC mA measurements
(and because I don't have one, therefore I plead guilty Your Honour, and throw myself at the mercy of the EEVblog Court.. :scared:)   

and always the local oz sellers are either out of stock
or want $700 for one  :o  so when queeried about that, they reply it's currently out of stock but keeps the Ebay listing going =  :wtf:  +  :palm:

----------------------------

I'm off to check out the other post too  > Re: Why do I need more than 1 oscilloscope?

 

Offline joseph nicholas

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Re: Why do I need more than 1 multimeter?
« Reply #37 on: July 26, 2019, 12:43:48 am »
I just got a used Unit-e meter from a pawn shop for 7.50 usd.  The milliamp fuse was blown but other than that it works good. 

Miles ahead of the cheap Chinese 830 type meters.

 

Offline rstofer

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Re: Why do I need more than 1 multimeter?
« Reply #38 on: July 26, 2019, 01:47:33 am »
When you take a small boat to sea, you take one compass or three but never two.
 
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Offline Berni

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Re: Why do I need more than 1 multimeter?
« Reply #39 on: July 26, 2019, 05:22:00 am »
Why would one need more than 1 scope? Well you need a 2nd scope to fix the 1st scope when it breaks of course. ;D

Yeah its a bit harder to justify, but i do have a good reason for having two scopes. One of them is a high performance 4GHz scope running windows. While the performance is certainly nice there are down sides such as the inputs being more sensitive to damage, slow waveform update rates, slow boot times, clunky to set up, big, noisy, power hungry... etc So next to it i also have a old Agilent MSO6000. It might not sound as impressive at 300MHz and 2GS/s, but its a fast booting quiet scope with very good waveform update rates and is quick to set up. And because of that most of the time i end up using the smaller scope for convenience.

With how good digital scopes are getting its harder to justify keeping around old analog scopes around, but one wouldn't throw out a perfectly working scope right?
 

Offline BravoV

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Re: Why do I need more than 1 multimeter?
« Reply #40 on: July 26, 2019, 05:38:27 am »
Some of you need to visit this old popular thread -> Show your Multimeters

Quote from an example post from that thread.

Courtesy of ModemHead, all used & repaired.  :o
 
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Offline garethw

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Re: Why do I need more than 1 multimeter?
« Reply #41 on: July 26, 2019, 07:05:56 am »
The correct answer is you do not need them if you asked that question.
This is great!
I was a car mechanic and you couldn’t have enough tools. Now my mechanic days are behind me but my love of tools and equipment is still strong.


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Offline Nusa

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Re: Why do I need more than 1 multimeter?
« Reply #42 on: July 26, 2019, 08:05:30 am »
Until you learn to use the one you have, you don't really need another one. Unless the one you have is unusable, of course.
 

Offline tszaboo

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Re: Why do I need more than 1 multimeter?
« Reply #43 on: July 26, 2019, 09:37:28 am »
I was making test documentation for a ontified body, doing temperature test of a component, logging data. You can use specialised equipment for it, but DMM is just more versatile, and you only need the setup every once in a while. So I was measuring voltage, current, temperature with a soldered in thermocouple, ambient temperature with a PT1000. All with 4 calibrated multimeter, 34465A, every x second sample taken. Few pages describing the test setup, complete with pictures, architecture etc.
 

Offline TheNewLab

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Re: Why do I need more than 1 multimeter?
« Reply #44 on: July 26, 2019, 09:38:54 am »

All the above reasons, and MORE* coming     (*meter/s in your 'posession')
and do you really need another phone or the latest shiny adware magnet one? Meters are more fun, survive drops better and no Facebook BS

----------------------------

I'm off to check out the other post too  > Re: Why do I need more than 1 oscilloscope?
What!??
Where's "Why do I need more than 1 oscilloscope?"   :-BROKE  >:D
 

Offline BravoV

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Re: Why do I need more than 1 multimeter?
« Reply #45 on: July 26, 2019, 10:03:20 am »

All the above reasons, and MORE* coming     (*meter/s in your 'posession')
and do you really need another phone or the latest shiny adware magnet one? Meters are more fun, survive drops better and no Facebook BS

----------------------------

I'm off to check out the other post too  > Re: Why do I need more than 1 oscilloscope?
What!??
Where's "Why do I need more than 1 oscilloscope?"   :-BROKE  >:D

Well, since you asked for it ...  >:D



-> Why does everyone have twenty oscilliscopes?

-> Do you collect oscilloscopes?

Words of warning, cause you may ended up joining the TEA cult ...   :-DD
« Last Edit: July 26, 2019, 10:16:46 am by BravoV »
 

Offline Electro Detective

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Re: Why do I need more than 1 multimeter?
« Reply #46 on: July 26, 2019, 10:49:01 am »
Anyone with that many oscilloscopes above, is past having to justify having them to jealous people 
and time to get a few more multimeters to fill those bench cavities 


I do have a simple query: what's the deal with the vertical positioned DSO in the top left corner?

A measurement trick I'm not aware of, the unit has horizontal trace issues, 'space, the final frontier..'

or the owner had one too many beers ?   ;D

 
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Offline rsjsouza

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Re: Why do I need more than 1 multimeter?
« Reply #47 on: July 26, 2019, 11:33:33 am »
To me the coolest looking scope there is the red one in the middle! I didn't know that lab T&M gear came in such nice colors! :-DD

(automotive and portable certainly are part of the rainbow)
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Offline Electro Detective

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Re: Why do I need more than 1 multimeter?
« Reply #48 on: July 27, 2019, 09:26:16 am »

The orange multimeter is thinking...  \$\Omega\$

"just what do they hope to achieve parking my butt here amongst the big boys

...with no leads?"
    :-//

 
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Offline bd139

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Re: Why do I need more than 1 multimeter?
« Reply #49 on: July 27, 2019, 09:54:01 am »
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.
 
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