Multimeter Shootout

[EEVblog]

Heads-up everyone.
Many people have requested that I do reviews of more affordable multimeters rather than just the top shelf stuff.
Rather than review one-by-one I'm thinking of having one big "Under $XX Multimeter Shootout" and am and trying to tee this up.
And it'll be "to destruction" of course!

I don't know what the $XX amount will be, taking suggestions on that too, but certainly under the $100 mark. The idea is to find the best value/performance meter under that amount.

Rather than just pick the meters myself, I'd thought I'd also let viewers suggest ones they are interested in.
So if you want to see a particular model reviewed, let me know, but it MUST be picked from here, and be at least under that $100 mark:
http://www.tequipment.net/

Thanks.
Dave.

[jimmc]

At the risk of incurring your wrath can I suggest one not from that source.

At the very bottom of the pile is the ubiquitous  DT830B, the cheapest I've found it is here £2.71 ($4.50) including postage!)
http://cgi.ebay.co.uk/LCD-Digital-Multimeter-Voltmeter-Ammeter-Meter-OHM-DVM_W0QQitemZ390171973976QQcmdZViewItemQQptZUK_BOI_Electrical_Test_Measurement_Equipment_ET?hash=item5ad80fd958
This would at least show what the very bottom of the range is like.

I confess I have a few in addition to my main meters, they do have their uses if their limitations are understood.


Jim

[desolatordan]

At the risk of incurring your wrath can I suggest one not from that source.

At the very bottom of the pile is the ubiquitous  DT830B, the cheapest I've found it is here £2.71 ($4.50) including postage!)
http://cgi.ebay.co.uk/LCD-Digital-Multimeter-Voltmeter-Ammeter-Meter-OHM-DVM_W0QQitemZ390171973976QQcmdZViewItemQQptZUK_BOI_Electrical_Test_Measurement_Equipment_ET?hash=item5ad80fd958
This would at least show what the very bottom of the range is like.

I confess I have a few in addition to my main meters, they do have their uses if their limitations are understood.


Jim

Was just going to suggest the cheap $3 ones from Harbor Freight, looks like they're the exact same meter.
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=98025

EDIT: Oops, didn't noticed the Tequipment note in the post.

Extech 430
http://www.tequipment.net/ExtechEX430.asp

[EEVblog]

At the risk of incurring your wrath can I suggest one not from that source.

Only problem with that is that Tequipment are providing the meters for nix.
So I can get other ones, but I'll have to scrounge them from somewhere else or buy them myself.

Dave.

[freddyk]

  A multimeter for only $4.50? I'd love to see how that one measures up to other multimeters.

It would be fun to have my preconception of cheap China Export blown to pieces if it (against all odds?) proved not to be as bad as the price suggests. 

Dave, I'm going to donate a small amount to you ($42 ought to be the optimal amount), hoping that you include one of those mega-cheap multimeters in the review...

[migsantiago]

This one is not sold at Tequipment... but maybe you could check it out. It seems to be a Fluke 17B "clone"...

VC99 3 6/7 Multimeter analog bar C F better FLUKE 17B
http://cgi.ebay.com/VC99-3-6-7-Multimeter-analog-bar-C-F-better-FLUKE-17B_W0QQitemZ120513720463QQcmdZViewItemQQptZBI_Electrical_Equipment_Tools?hash=item1c0f2d708f

$36.99USD

[MTron]

I have had some good experiences with other Amprobe meters, and this one just fits your bill for under $100

http://www.tequipment.net/Amprobe35XP-A.html

[EEVblog]

A multimeter for only $4.50? I'd love to see how that one measures up to other multimeters.

It would be fun to have my preconception of cheap China Export blown to pieces if it (against all odds?) proved not to be as bad as the price suggests. 

Dave, I'm going to donate a small amount to you ($42 ought to be the optimal amount), hoping that you include one of those mega-cheap multimeters in the review...

Thanks for the donation, I can get a few more now!
Somehow I don't think the $5 meter is going to compare with a $50 meter, at which price point you can actually get a decent quality meter.

Dave.

[csadzuki]

I would be very interested in your opinion/review of UNI-T multimeters.
http://www.uni-trend.com/software/DMM%20Catalog_2009.pdf
(I have a UT61C, but my feelings are mixed...)

The general opinion seems to be that they are great bang for the buck meters.
They are sold under many names (VoltCraft, etc.).
(Sorry, not sure if tequipment.net carries them. )

[EEVblog]

VC99 3 6/7 Multimeter analog bar C F better FLUKE 17B
http://cgi.ebay.com/VC99-3-6-7-Multimeter-analog-bar-C-F-better-FLUKE-17B_W0QQitemZ120513720463QQcmdZViewItemQQptZBI_Electrical_Equipment_Tools?hash=item1c0f2d708f

A few people have asked about that one, as it seem to be prolific on Ebay. So I've just bought one.

Dave.

[migsantiago]

It'll be interesting to watch some clone wars... Fluke vs. whoknowswhat... 

[Simon]

VC99 3 6/7 Multimeter analog bar C F better FLUKE 17B
http://cgi.ebay.com/VC99-3-6-7-Multimeter-analog-bar-C-F-better-FLUKE-17B_W0QQitemZ120513720463QQcmdZViewItemQQptZBI_Electrical_Equipment_Tools?hash=item1c0f2d708f

A few people have asked about that one, as it seem to be prolific on Ebay. So I've just bought one.

Dave.

oh thanks Dave I have one of those and while its my top meter (while i recover from my investment in the rigol scope) I don't like to trust it, a lot of your comments on it when I posted about it whilst considering it were true: no SMD all standard parts and well just nothing like I hope a real fluke is, I also have good reason to beleive that the temp measurement reads an astounding 5 C over the actual temp !

[EEVblog]

So how do people think I should run this comparison?
I don't think it's fair to compare a $5 meter with a $70 meter for example, so I'm probably going to exclude those $5 meters.
An how do you fairly compare a better quality $50 meter with basic features, to a lesser quality $50 meter with all the bells and whistles?

Categories?
Any ideas?

Dave.

[dmlandrum]

My first thought is to compare across comparable feature lists and leave price for last. So, group all multimeters by feature range, do your comparison, rank them, and then factor the price into it. You can then let that alter your rankings if you desire, or you can take each "feature-equivalence" category and choose a "best performer" and then a "best bang for the buck." Who knows, they might be the same in some cases.

I hope that makes sense. I'm not saying it's a good idea, just that it's my first.

[armandas]

I think it is a good idea to throw in one or two $5 meters. Even if they can't compare with others, you can tell everyone how horrible they are, or better yet, "test" their input protection (if you know what I mean )

[migsantiago]

A comparison table would be enough I think. The columns should be the dmm models and every row should be a feature.

First, the electronic and electric features: voltage precission, battery endurance, capacitance measurements, transistor HFE, number of displayed digits, etc.

Another group of rows should be the number of standards that the dmm has (that CAT III thing labeled on the probes for example).

Then the "appeal" features: product looks, shape, shock resistance, beeper loudness, battery replacement, display readability and the most special one... the feel.

And the last group of rows... the tough tests... free falls, apply 220VAC while measuring ohms (yeah, it happens! hehe), water proof, etc.

The columns (dmm models) could be arranged from lower to higher price.

[Simon]

My first thought is to compare across comparable feature lists and leave price for last. So, group all multimeters by feature range, do your comparison, rank them, and then factor the price into it. You can then let that alter your rankings if you desire, or you can take each "feature-equivalence" category and choose a "best performer" and then a "best bang for the buck." Who knows, they might be the same in some cases.

I hope that makes sense. I'm not saying it's a good idea, just that it's my first.

sounds good, I have meters that are almost identical but i apid very different prices for them and have seen them for much less recently, with price on these cheap meters it is more down to channels you buy through than what they do or who branded them

[MTron]

So how do people think I should run this comparison?
I don't think it's fair to compare a $5 meter with a $70 meter for example, so I'm probably going to exclude those $5 meters.
An how do you fairly compare a better quality $50 meter with basic features, to a lesser quality $50 meter with all the bells and whistles?

Categories?
Any ideas?

Dave.

Well.....you could always do some kind of standardization of score... develop say, 4 categories out of 10 to be graded on, divide each category by the price, and sum the total from each of thr 4 categories....might come to some kind of best bang for the buck....LOL

i think ive been in the science papers to much.....

In all seriousness, how about 2 broad categories. an ultra cheap, bare bones, first multimeter you buy ever just to test wall voltage category, and then the decently accurate well equipped multimeter for someone starting out in the field

Personally i found your previous reviews on multimeters quite informative, and the one were you did a brief overview of the Meterman multimeter peaked my interest as the Meterman (Now Amprobe) multimeters seemed to be pretty decent in quality....i actually went out a bought an Amprobe 34XR-A to replace my 15 dollar import meter

[domm123]

A multimeter for only $4.50? I'd love to see how that one measures up to other multimeters.

It would be fun to have my preconception of cheap China Export blown to pieces if it (against all odds?) proved not to be as bad as the price suggests. 

Dave, I'm going to donate a small amount to you ($42 ought to be the optimal amount), hoping that you include one of those mega-cheap multimeters in the review...

I would also like to see a $4.50 multimeter taking measurement, and compare it side by side with a expensive one! 

[PetrosA]

In this price range I'd be interested in a backup/secondary DMM. My primary is now an Agilent u1211a clamp meter but I'd like to have a second one for measuring voltage and amperage together. Since I work on line voltages, anything I use has to be at least CAT III to 600V and that is the primary criterion I used gathering my list of meters. I stayed away from Amprobe only because I know you've already gotten a lot of requests for them.

Here's the list:

http://www.tequipment.net/ReedST-9918.asp
http://www.tequipment.net/Ideal61-320.asp
http://www.tequipment.net/BK2708B.html

Sure, I dream of a high end data logging DMM, but there are lots of other tools on my "to buy" list

Edit to add:

I didn't notice that the Reed 9918 was discontinued and the replacement is just over $100. The 9917 would also fit my requirements.

http://www.tequipment.net/ReedST-9917.asp

Mini rant - tequipment.net is a great source and has excellent live chat help (I've used it before) but they really need to do some work on organizing the products better, as well as making the search functions more useful (like by price and availability).

[Simon]

not sure if it has alreadbeen mentioned but I'm considering the amprobe AM220 after getting fed up with that fluke 17B mikitake from china off ebay. it looks like a good all round meter but for 30 quid I'd dubious as thats what I paid for the peice of crap I have from ebay

[flano]

Dave,

Really enjoy your reviews. I'm looking getting a new meter like.

http://www.tequipment.net/UEiDM397.html

So would be interested in a review of one of their lower priced units.

http://www.tequipment.net/UEiDM391.html

As for how to review them, I think you should rate them on their:-
- Construction - How relieable will they be?
- Safety - What standards do they conform to? Can they take 240V on the ohms range? ...
- Accuracy compared to your Fluke 87
- Feature set/Bang for buck.

Look forward to watching the shootout.

Thanks Mike

[Simon]

Clone war is a good idea the VC99 meter very comon on ebay and sold as a fluke 87 equivalent putting it against the real one would be good.

[domm123]

My cheap $5 meter have arrived!! Some picture.. It is very small and feels very light as compare to my fluke 87-v.
Btw, it does not look as bad as the cheap meter that dave have. The soldering on the pcb is pretty neat, and it uses smd component.

Model is DT-830B

[lebeno]

Dave, super idea, this multimeter shootout!

Because I was planning to buy a second, more accurate DMM, I did some "market research" and put  the specs of the products I liked in this document: Quality Autoranging TrueRMS multimeters compared.

The document is far from complete: a lot of multimeters could be added and in most cases for the accuracy of a given function (e.g. DCV) I took the best one I could find for the different DCV ranges. Also, I "calculated" the total accuracy for every function by taking the measuring accuracy and then adding the "counts" accuracy divided by the total number of counts. Dunno if this formula is any good, but I wanted something to compare the bare facts.

The Cineese Uni-T UT71C seems to be a very good multimeter (on paper anyhow). Compared to the Fluke 87 V and the Gossen Metrahit PRO, it almost beats them at every spec at a third of the price! But then again, my comparison is probably very inaccurte, incomplete, or Uni-T could be lying or incomplete? And the dial is doubtfully as sexy als the Gossen's

Anyhow, I did find a nice video that seems to suggest the Uni-T multimeters have an easy calibration feature:

Uni-T also has the UT71D and UT71E models. Apart from the number of data logging records or a power meter option, they have the same specs.

If you guys think this comparison table is any good or you have suggestions, I can give you write permission to add stuff.

[EEVblog]

For those interested, the meters on their way soon are (hopefully):

$50 price category:
Extech EX320
Amprobe AM220
Global Specialties PRO-50
Elenco M-2625
VC99 ebay cheapie

$100 price category (all TRMS):
BK Precision BK2709B
Amprobe 34XR
Extech EX505
Ideal 61-342
UEi DM391

Dave.

[Simon]

would be very interesting to see the comparison of the AM220 to the VC99,  have both as main meters and paid the same for them (both ebay), I think the VC99 is cheap garbage with as many counts and features thrown in as possible, the AM220 seems to have the same capabilites but slightly less for example 4000 count versus 6000 count and the max ranges that go with that but much better quality and maybe accuracy, there is a 20 mV difference between the 2 and I think I'd trust the AM220 over the VC999

[stevestk]

I guess the one problem is trying to reach all the audience tuning in. When your're new to a hobby you don't know what you don't know. For someone getting started like me, I'd like to know what the minimum expense is that I can get away with while having a usable instrument. If I buy a $30-$50 dollar instrument what won't I be able to accomplish as apposed to a $100 meter. Or is the issue safety or longevity? Or can you tell me why I'll regret my purchase and will have to spend more money in a few months for a replacement. These same questions apply to most test equipment purchases for novices.

[Simon]

anything around £30/$50 should make a decent meter to start with just don't go lower, my £10 meters actually failed to survive a flight in a hold (in my suitcase). Personally although I've hardly used it as of yet I'd recomend the amprobe AM220, it seems to be a reliable machine and costs the same as the micky taking meters on ebay (althoug you can get the AM220 on ebay too). a £50+ fluke seems to make a good baseline meter and over 100 pounds you should get a nice durable machine

[saturation]

You did a wonderful job on the comparison sheet, but there are 3 things in it that are difficult to test.  The UT71C DC performance on the U-Tube video was impressive, but so was this:



How durable is the unit ?  How long will it stay in spec, under what conditions such as varying environmental temperatures?

How protected is it really from transients, and is it truly rated for whatever CAT level its specified for?

If you use it purely for electronics design work at home it should be fine, and CAT ratings may not be important.  In that case, I'd be more concerned with how accurate it will continue to be within the 1st year you've owned it.  Also, with these no-name meters, its hard to say if their published specs are true compared to the reputable meters or with what an independent reviewer will find out  ... like Dave will do soon.

I'm still looking for a very accurate DC meter, and thanks to you, the Uni-T models is something I'll look into ... I'd previously reviewed its portable oscilloscope but decided against it.

Dave, super idea, this multimeter shootout!

Because I was planning to buy a second, more accurate DMM, I did some "market research" and put  the specs of the products I liked in this document: Quality Autoranging TrueRMS multimeters compared.

The document is far from complete: a lot of multimeters could be added and in most cases for the accuracy of a given function (e.g. DCV) I took the best one I could find for the different DCV ranges. Also, I "calculated" the total accuracy for every function by taking the measuring accuracy and then adding the "counts" accuracy divided by the total number of counts. Dunno if this formula is any good, but I wanted something to compare the bare facts.

The Cineese Uni-T UT71C seems to be a very good multimeter (on paper anyhow). Compared to the Fluke 87 V and the Gossen Metrahit PRO, it almost beats them at every spec at a third of the price! But then again, my comparison is probably very inaccurte, incomplete, or Uni-T could be lying or incomplete? And the dial is doubtfully as sexy als the Gossen's

Anyhow, I did find a nice video that seems to suggest the Uni-T multimeters have an easy calibration feature:

Uni-T also has the UT71D and UT71E models. Apart from the number of data logging records or a power meter option, they have the same specs.

If you guys think this comparison table is any good or you have suggestions, I can give you write permission to add stuff.

[EEVblog]

The meters will be on their way on Monday, here they are at tequipment.net who are providing them!

Dave.

[PetrosA]

The meters will be on their way on Monday, here they are at tequipment.net who are providing them!

Dave.

Bravo!

[Kiriakos-GR]

I am a bit skeptic , because the 50$ limit , excludes many models , that some people all ready own.

But the positive part is , that the upcome would be an comparison of apples with apples.
And it will be quite educational ..     

For something like that , that needs time , its worth the waiting, and there is no need anyone to stress Dave about  acting faster ...

Detail and speed , does not coexist .. We have always to choose our priority s.
So I vote for detail = patience .     

[EEVblog]

I am a bit skeptic , because the 50$ limit , excludes many models , that some people all ready own.

But the positive part is , that the upcome would be an comparison of apples with apples.
And it will be quite educational ..     

For something like that , that needs time , its worth the waiting, and there is no need anyone to stress Dave about  acting faster ...

Detail and speed , does not coexist .. We have always to choose our priority s.
So I vote for detail = patience .     

Yes, the hard part was picking suitably comparable models. And no matter what gets picked, someone will complain I didn't include XXXXX
But I was essentially limited to what tequipment.net offered, as they have generously donated the gear.
I hope the $50 mark and $100 was a reasonable compromise, and it seemed to work out quite, as for example all the $100 units have TRMS, but the $50 units don't. And one of them is waterproof and shock proof! 

It'll sure take some time to review and do a tear-down of them all, so I'll have to deliberately keep it very brief with comparison tables etc.

I'll also have to do it in two separate blogs, the $50 ones and then the $100 ones.

Dave.

[saturation]

You could take your time, and do a detailed comprehensive eval in stages.

The accuracy in DMM functions versus printed specs is something we all want to know which you can give us quickly in a rundown.  But long term stability will need time, and accelerated testing will be hard to validate i.e., operation in higher ambient temps and humidity.

Then there's drop tests, waterproof etc.,

Then there's the ergonomics of actual use.

Then safety, CAT I-IV level testing.

Lots of fun for you and us!

I am a bit skeptic , because the 50$ limit , excludes many models , that some people all ready own.

But the positive part is , that the upcome would be an comparison of apples with apples.
And it will be quite educational ..     

For something like that , that needs time , its worth the waiting, and there is no need anyone to stress Dave about  acting faster ...

Detail and speed , does not coexist .. We have always to choose our priority s.
So I vote for detail = patience .     

Yes, the hard part was picking suitably comparable models. And no matter what gets picked, someone will complain I didn't include XXXXX
But I was essentially limited to what tequipment.net offered, as they have generously donated the gear.
I hope the $50 mark and $100 was a reasonable compromise, and it seemed to work out quite, as for example all the $100 units have TRMS, but the $50 units don't. And one of them is waterproof and shock proof! 

It'll sure take some time to review and do a tear-down of them all, so I'll have to deliberately keep it very brief with comparison tables etc.

I'll also have to do it in two separate blogs, the $50 ones and then the $100 ones.

Dave.

[Kiriakos-GR]

The accuracy in DMM functions versus printed specs is something we all want to know which you can give us quickly in a rundown.  But long term stability will need time, and accelerated testing will be hard to validate i.e., operation in higher ambient temps and humidity.

Then there's drop tests, waterproof etc.,

Then there's the ergonomics of actual use.

Then safety, CAT I-IV level testing.

Lots of fun for you and us!

   As independent " observer " ,

I would describe this message as a "Hit under the belt"  

Or like an side way movement,  to influence the judgment of the reviewer ..  

Everything are understandable    
This upcoming review  had throw sky high , the expectations of this community ..
soon we will need the help, of the Australian Firefighters .  

[EEVblog]

Does anyone have an Amprobe 34XR?
Just took it out of the pack and tried it and it gives a very sickly sounding beep every time the range switch is moved. Not only is it incredibly annoying, it actually sounds like the unit is faulty in some way. Almost like the battery is out of juice and it's trying to beep a last gasp (Yes, I checked that battery)
Can anyone confirm that their unit does this?

Thanks
Dave.

[Simon]

You could take your time, and do a detailed comprehensive eval in stages.

The accuracy in DMM functions versus printed specs is something we all want to know which you can give us quickly in a rundown.  But long term stability will need time, and accelerated testing will be hard to validate i.e., operation in higher ambient temps and humidity.

Then there's drop tests, waterproof etc.,

Then there's the ergonomics of actual use.

Then safety, CAT I-IV level testing.

Lots of fun for you and us!

I'm particularly interested in accuracy (I am after all a QC inspector by day) as i have two meters, the amprobe AM220 and the VC99 off ebay and they gave a slightly different voltage reading for the same voltage, naturally i trust the amprobe more

[alm]

I'm particularly interested in accuracy (I am after all a QC inspector by day) as i have two meters, the amprobe AM220 and the VC99 off ebay and they gave a slightly different voltage reading for the same voltage, naturally i trust the amprobe more

The problem with testing accuracy is that it's a statistical quantity measured over a period of time. To get a good idea of accuracy, you need to track multiple samples over a few years, not something we can expect Dave to do. The initial accuracy does say something about QC, but since I don't expect a <$100 DMM to ever be calibrated, the long term specs are the important ones.

[Simon]

as far as i know you can't "callibrate" a multimeter ? I know you can send them away for "calibration" but they do not get callibrated as such they are merely checked for accuracy.

On the contrary you can take a measurement and work out if it is withing ther tollerance stated, of course 1 year down the line you should recheck the unit to verify it is still accurate. I'd not be surprised though if many cheap multimeters are sold with poor accuracy to start with.

[Kiriakos-GR]

as far as i know you can't "callibrate" a multimeter ? I know you can send them away for "calibration" but they do not get callibrated as such they are merely checked for accuracy.

Well this Damn Fluke 87V , made me to believe that they do get calibrated ... by software.
I have read 4 times the manual , and check the service manual of the old 87 III .
Even every message in the LCD are programed, with the proper tools, you can calibrate it , or even make it to speak Russian ..  

Instead of  the { LEAD } warning , it will say {??}  

Text taken from the service manual:

After pressing {Auto Hold}, wait until the step number advances before changing
the calibrator source or turning the Meter rotary knob.
If the Meter rotary knob is not in the correct position, or if the measured
value is not within the anticipated range of the input value, the Meter emits
a double beep and will not continue to the next step.
Some adjustment steps take longer to execute than others (10 to 15
seconds). For these steps, the Meter will beep when the step is complete.
Not all steps have this feature.
8.  After the final step, the display shows "End" to indicate that the calibration
adjustment is complete. Press {Auto Hold} to go to meter mode.

[EEVblog]

I'm particularly interested in accuracy (I am after all a QC inspector by day) as i have two meters, the amprobe AM220 and the VC99 off ebay and they gave a slightly different voltage reading for the same voltage, naturally i trust the amprobe more

The problem with testing accuracy is that it's a statistical quantity measured over a period of time. To get a good idea of accuracy, you need to track multiple samples over a few years, not something we can expect Dave to do. The initial accuracy does say something about QC, but since I don't expect a <$100 DMM to ever be calibrated, the long term specs are the important ones.

Correct, absolute accuracy is not something I can do with any sense of authority with only one sample, limited time, and no thermal chamber.
Remember, most meters are only "accurate" to the 2nd LSD, so being up to 10 counts out between meters can be expected. But in practice it's usually better than that, even on the cheapies.
I'd be surprised if any of these cheapies are more than say 5 counts out from my reference Fluke out of the box.

Sadly, a lot of beginners think that if it reads the same as the Fluke then it's obviously "just as good". The truth of course is nothing like that.

Dave.

[EEVblog]

as far as i know you can't "callibrate" a multimeter ? I know you can send them away for "calibration" but they do not get callibrated as such they are merely checked for accuracy.

Essentially correct.
I've talked about this in my meter counts blog.

"adjustment" is usually a separate process that is only done if required or requested.

Modern good quality meters will have software calibration adjustment instead of old style trimpots.

Dave.

[alm]

Technically, calibration is just checking if it's within specs, although in the test & measurement industry, this is often called 'performance verification', and calibration as performance verification + adjustments. Any multimeter can be checked, and most can be adjusted. Even my father's cheap Voltcraft DMM has two internal trimmers. The more recent and expensive multimeters usually allow closed-case calibration (from the front panel or an external interface). In many cases, a cal lab will adjust anything outside specs (or something outside 50% of specs), although you can request them not to if you want to track the aging yourself.

Accuracy specs are usually valid for at most a year (assuming they have any grounding in reality to begin with), so if you care about accuracy, you should send it out for calibration/adjustment at least once a year. If you don't, you're essentially in unknown territory, accuracy-wise. Although most high-quality meters rarely go out of spec and are likely to be close to factory specs, even after more than ten years. I wouldn't expect cheap meters to have the same stability, but you never know.

[Simon]

there probably is a method of actully calibrating a meter but you must assertain first what the trst company mean by callibration, you must make sure they mean that they will recallibrate the meter, this sounds obvious but with the thousands of models around they will have to know how to work on each model and possibly have the equipment neccesary. Although I know it is not impossible I think most companies by "callibration" will mean check to see if it is in tollerance

[Rhythmtech]

i think manual re-calibration will be too tedious as the device named "multi" meter. i guess you have to calibrate everything, V,A,mA,Ohm etc. And even my cheapo one, for years still not far off enough to alert me for a re-calibration (i dont even noticed it!). Thats why they simply left that out and do it properly in the software. Just my 2cents. 

If you do 5 points for each range, you could do the calibration check in under and hour. On many modern digital meters some of the functions are in software and may not require calibration as the same hardware that has already been checked is used, although I personally would consider it bad practice to not check every range of every function. Usually when meters are "out" of calibration it is not out in every range so you only have to make one adjustment for that range.  If the meter is out across all ranges, I would suspect more than just adjustment is necessary. More like the meter is broke and needs to be replaced.

[alm]

Usually when meters are "out" of calibration it is not out in every range so you only have to make one adjustment for that range.  If the meter is out across all ranges, I would suspect more than just adjustment is necessary. More like the meter is broke and needs to be replaced.

Or it's an offset error which is equal on every range. I have an HP DMM that was off on all resistance ranges (even four wire) by something like -0.4 ohm. A dead short read -0.4 (4-wire), a 100 ohm resistor read something like 99.6 ohm (and 99.9 something on other meters), a 1k resistor was 999.6ohm, and so on. After re-calibrating the zero ohm measurement on all resistance ranges, they were all within spec again.

[Rhythmtech]

Usually when meters are "out" of calibration it is not out in every range so you only have to make one adjustment for that range.  If the meter is out across all ranges, I would suspect more than just adjustment is necessary. More like the meter is broke and needs to be replaced.

Or it's an offset error which is equal on every range. I have an HP DMM that was off on all resistance ranges (even four wire) by something like -0.4 ohm. A dead short read -0.4 (4-wire), a 100 ohm resistor read something like 99.6 ohm (and 99.9 something on other meters), a 1k resistor was 999.6ohm, and so on. After re-calibrating the zero ohm measurement on all resistance ranges, they were all within spec again.

Yeah, I agree that makes sense. I should have been more explicit.  For example, if volts, amps, and resistance all required adjustment then I would suspect something happened to the meter. In which case, you could shorten the cal interval and verify that the adjustment took or the meter needs to be replaced.

[RayJones]

there probably is a method of actully calibrating a meter but you must assertain first what the trst company mean by callibration, you must make sure they mean that they will recallibrate the meter, this sounds obvious but with the thousands of models around they will have to know how to work on each model and possibly have the equipment neccesary. Although I know it is not impossible I think most companies by "callibration" will mean check to see if it is in tollerance

This very true, especially for expensive signal generators.

For example, a calibrated unit usually means the power / frequency was within the published specs for the unit. ie 0dBm may actually really be 0.5dBm

Adjustment requires an even greater financial outlay, and you will be contacted if you desire this if your unit is found to be out of spec.

[saturation]

An alternative to calibration for DIY without access to a lab with calibrated gear is to buy a voltage reference or DMM calibrator.  It should calibrate the most critical ranges.  alm on this thread summarizes the limitations.

https://www.eevblog.com/forum/index.php?topic=601.0

Essentially you buy a lab's voltage, current and resistance reference board.  This is calibrated by the seller.  Every 6-12 mo you can return the reference board to them for recalibration, and they mail it back to you, ~ cost $5 US after 1 year, free prior.  I estimate total cost would run $10-15, mostly from the postage.

I think Dave said once you are aware of the drift of a particular DMM, calibration may show that its rock stable year after year, and annual checkups become 'less' or unnecessary, unless you are in a professional setting.  If you own several DMM, you can calibrate them at different times of the year, so as they drift, you can cross reference them against each other to check accuracy.

On the side, Fluke DMM owners know them be quite stable, something not immediately viewable by its appearance or mentioned in its manual or sales literature; a measurement of some voltage references show my 85 still reads true to spec 20 years since its last recalibration.

Here's a fellow describing his uncalibrated 10 year old Flukes:

http://www.cappels.org/dproj/1.024voltreference/portvoltref.html

[alm]

Indeed, the stability of high-quality multimeters can be much better than specced in the datasheet, the value in the datasheet is probably something like the three-sigma value under worst-case conditions, most meters are not worse-case. Especially the long-term drift is often quite low. It's not unusual for a meter to still meets it specs after many years without calibration. The trick is how to know if this is the case. This obviously won't cut it in a commercial environment where it's used for production testing, you want impressive official documents to impress your managers and customers, and to claim that your process that produces equipment that dies after two years has a constant quality, and will always die between two years and two and a half years.

Calibration is all about 'probably accurate' anyway, the minute the meter is put in a box and tossed in the UPS van, it might have drifted (although modern meters without trimmers are much less susceptible to shocks). The manufacturer has designed it so it probably won't drift more than X within a year, and you can use your own historical data to back it up. Sometimes they perform worse than manufacturers specs, I've heard about a metrologist that had some meters on a three month cal cycle, and they still barely met their 1-year specs.

Even with real calibration, all you have is a certificate that it was within factory specs at some time in the past, a datasheet from the manufacturer that claims that it won't drift more than X in the calibration interval, and if you're lucky some historical stats. None of this guarantees that the measurement you take today is accurate. I think Dave touched on this in a past blog.

[saturation]

Holding calibration over many years is a feature worth advertising, calibration costs over time quickly add up; you can buy a new top DMM every 4-5 years and as you'd estimate, a single calibration cost more than many DMM.

Although the Fluke is rugged, I don't mistreat it and a homebuild DMM either, nor is it exposed to the extremes of its operating range, its been a 'house' meter all its life living in relative controlled conditions. I do take a Radio Shack DMM to the field often: hot, humid, bumpy, high humidity, so this thread has given me the incentive to calibrate it against the Fluke and see what continued environmental exposure will do to its drift.

Indeed, the stability of high-quality multimeters can be much better than specced in the datasheet, the value in the datasheet is probably something like the three-sigma value under worst-case conditions, most meters are not worse-case. Especially the long-term drift is often quite low. It's not unusual for a meter to still meets it specs after many years without calibration. The trick is how to know if this is the case. This obviously won't cut it in a commercial environment where it's used for production testing, you want impressive official documents to impress your managers and customers, and to claim that your process that produces equipment that dies after two years has a constant quality, and will always die between two years and two and a half years.

Calibration is all about 'probably accurate' anyway, the minute the meter is put in a box and tossed in the UPS van, it might have drifted (although modern meters without trimmers are much less susceptible to shocks). The manufacturer has designed it so it probably won't drift more than X within a year, and you can use your own historical data to back it up. Sometimes they perform worse than manufacturers specs, I've heard about a metrologist that had some meters on a three month cal cycle, and they still barely met their 1-year specs.

Even with real calibration, all you have is a certificate that it was within factory specs at some time in the past, a datasheet from the manufacturer that claims that it won't drift more than X in the calibration interval, and if you're lucky some historical stats. None of this guarantees that the measurement you take today is accurate. I think Dave touched on this in a past blog.

[EEVblog]

I just edited the basic footage I have for the $50 meter shootout and it's already 47minutes. That does not include intro, drop tests or conclusion which I haven't filmed yet!
It's just crazy! I'm sure no one wants to watch a >1 hour shootout.
What does everything think I should do?
I could maybe shoot a quick 10 minute monologue overview with no detail, and if you want the details you watch the full 1 hour+ version? So I'd upload two separate versions.
The only other alternative is to look at what I'm rambling on about and re-shoot quicker, but that would takes ages.
I can't really edit the existing footage much more, I'd have to leave tons of stuff out to get it down.

What do people think?

Dave.

[switcher]

 

Go with it Dave, but maybe split it into two 30-min segments.
cheers,

[csadzuki]

It's just crazy! I'm sure no one wants to watch a >1 hour shootout.

I, for one, would like to watch the 1+ hour version. 

[Simon]

yea I'd watch the lot, its like buying a DSLR and then throwing 99% of the info away on a JPEG output, give us all the nitty gritty dave, don't gather information only to toss it

[dengorius]

I agree, give us the director's cut
Maybe you could attach a little timetable that describes the content. In this way anybody who doesn't want to watch the whole thing can just skip ahead

@csadzuki
Great avatar

[redek]

I've been jonesing too long for a multimeter review, I'll be happy to watch the long version.

[MrPlacid]

Dave, go for the hour+ long review. Don't waste your time editing. I've seen bloggers who got lost in the habit of trying to produce, quality edited versions and what do they have to show? Maybe 4-5 episodes a year.

You can add another episode right afterward as a summary of the 1hr+ episode. It doesn't need any editing other than as a quick summary of the 1hr show without any multimeter footage other than you talking. That should make the other crowd happy too.

[saturation]

Go for the long one, its not just a review its entertainment.

You can preface the show with an executive summary, so start conclusions first, in case viewers wish for the short version.

I just edited the basic footage I have for the $50 meter shootout and it's already 47minutes. That does not include intro, drop tests or conclusion which I haven't filmed yet!
It's just crazy! I'm sure no one wants to watch a >1 hour shootout.
What does everything think I should do?
I could maybe shoot a quick 10 minute monologue overview with no detail, and if you want the details you watch the full 1 hour+ version? So I'd upload two separate versions.
The only other alternative is to look at what I'm rambling on about and re-shoot quicker, but that would takes ages.
I can't really edit the existing footage much more, I'd have to leave tons of stuff out to get it down.

What do people think?

Dave.

[KTP]

I was all excited about this review but yesterday my wife was out shopping at Frys and brought me home a Fluke 289 with FlukeView software (what a surprise! but she is a bit of a techy herself).

I have a nice wife.

I will still watch with interest while I learn this new meter, which has more controls than my oscilloscope.

[Simon]

I was all excited about this review but yesterday my wife was out shopping at Frys and brought me home a Fluke 289 with FlukeView software (what a surprise! but she is a bit of a techy herself).

I have a nice wife.

I will still watch with interest while I learn this new meter, which has more controls than my oscilloscope.

you lucky devil 

[MightyTwin]

I was all excited about this review but yesterday my wife was out shopping at Frys and brought me home a Fluke 289 with FlukeView software (what a surprise! but she is a bit of a techy herself).

Don't ever let go of her. Her kind of species is rare to get by these days.

 

-MightyTwin.

[PetrosA]

make it as long as you need to

[EEVblog]

I was all excited about this review but yesterday my wife was out shopping at Frys and brought me home a Fluke 289 with FlukeView software (what a surprise! but she is a bit of a techy herself).

That's an expensive impulse buy!
Nice score on both the wife and meter!

Dave.

[flano]

Dave,

Give us the 1+ hour, I like the details.

Thanks Mike

[link]

Dave,

I've got a chance to nab a new Extech EX505 for about $70. I wanna wait for your review but am afraid it might sell out. Would you recommend it for that price? Thanks. And I'm with everybody else. Make the review 1hr+ long. It's only the bad movies that need cutting.

[EEVblog]

I've got a chance to nab a new Extech EX505 for about $70. I wanna wait for your review but am afraid it might sell out. Would you recommend it for that price? Thanks. And I'm with everybody else. Make the review 1hr+ long. It's only the bad movies that need cutting.

Yeah, a bargain for $70 for a CAT-IV water/drop proof meter
If it's new in the box then it comes with a nice carry case with shoulder strap, and a magnetic hanger if you are into that sort of stuff.

They all seem pretty good, no real "pieces of shit" in the group (Yet to get the Uni-T). This will be a much closer shootout than the $50 one I suspect.

But as usual, they all have some bad points.

Dave.

[link]

Thanks Dave! I'll jump on it. Looking forward to your review. Liam

[cybergibbons]

Just saw this video on youtube:
https://www.youtube.com/user/extechvideos#p/u/8/F6nGjhAO67c

You see a bit inside the EX530... what is that white wire leading from one of the terminals across the PCB?

[dengorius]

Lol i like the basin drop and the car run over. Dave you should add them in your usual reviews

[link]

Lol i like the basin drop and the car run over. Dave you should add them in your usual reviews

Dave will probably take it to the next level - butane torch, liquid nitrogen, fat lady, etc.

[EEVblog]

Just saw this video on youtube:
https://www.youtube.com/user/extechvideos#p/u/8/F6nGjhAO67c

You see a bit inside the EX530... what is that white wire leading from one of the terminals across the PCB?

The wire is a kludge because they didn't lay out the board efficiently, which also results in a few cramped end-on components. Extech have admitted this and will endeavor to improve it in their next models.

That video was inspired by my Fluke 28-II video. I'll include the car test in future testing, along with other tests. I was going to do it for the Fluke 28, but plain forget in the end.

Dave.

[cybergibbons]

The wire is a kludge because they didn't lay out the board efficiently, which also results in a few cramped end-on components. Extech have admitted this and will endeavor to improve it in their next models.

Interesting - mainly because in the Fluke 28 test, it was one of the larger discretes (can't remember what it was, a small inductor?) that sheered off the board.

These do look like very robust meters though.

[EEVblog]

The wire is a kludge because they didn't lay out the board efficiently, which also results in a few cramped end-on components. Extech have admitted this and will endeavor to improve it in their next models.

Interesting - mainly because in the Fluke 28 test, it was one of the larger discretes (can't remember what it was, a small inductor?) that sheered off the board.

Yes, the main DC-DC SMD inductor sheared off not once but twice. Not from the actual solder joints, but the upper bobbin part. Not surprising I guess given that the ferrite material would be quite brittle.

From initial inspection, the Extech is clearly not in the same class as the Fluke 28, but it is 1/4 the price or something. Will be interesting to see how much abuse it can take.

Dave.

[saturation]

That video perked my interest, until I read the Amazon reviews for the EX530.  These reviews were made before eevblog but it does bring up some of Dave's points:

http://www.amazon.com/Extech-EX530-Heavy-Industrial-MultiMeter/product-reviews/B000EWW2T6/ref=dp_db_cm_cr_acr_txt?ie=UTF8&showViewpoints=1

For $200, you pay for the robustness, but it has a number of electronic flaws that aren't in cheaper but less robust DMM.  Its basically something you need to do general electrical rather than electronic work, but in a harsh environment.

In harsh environments, besides protection from mechanical failure, you still need a reliable electronic measuring tool.  You won't be in position to get your reading double checked because you may be carrying only one device to save weight, and I'd rather have a meter not read than read incorrectly.  Also, in wet environments, you want to be sure it reads true and doesn't harm you.

The wire is a kludge because they didn't lay out the board efficiently, which also results in a few cramped end-on components. Extech have admitted this and will endeavor to improve it in their next models.

Interesting - mainly because in the Fluke 28 test, it was one of the larger discretes (can't remember what it was, a small inductor?) that sheered off the board.

Yes, the main DC-DC SMD inductor sheared off not once but twice. Not from the actual solder joints, but the upper bobbin part. Not surprising I guess given that the ferrite material would be quite brittle.

From initial inspection, the Extech is clearly not in the same class as the Fluke 28, but it is 1/4 the price or something. Will be interesting to see how much abuse it can take.

Dave.

[cybergibbons]

I find it curious that multimeters can't get the continuity tester aspect right - it's a really simple feature. I've got a 15 year old Precision Gold meter from Maplin, and it's excellent - instant, slight latch on it, and the resistance it calls a short is at a good level.

Loads of other meters have scratchy, delayed buzzers, or pass far too high a resistance.

Re: the floating. Most meters that claim to float only do so without probes and strap attached.

[saturation]

Yes, or like this Extech 530, a tiny bit of engineering could fix these issues easily. 

I find more concerning when published specs are not the tested specs; it doesn't generate confidence in the company.  In the end, consumer trust is the best salesman, much over low price and exaggerated spec sheets.

I find it curious that multimeters can't get the continuity tester aspect right - it's a really simple feature. I've got a 15 year old Precision Gold meter from Maplin, and it's excellent - instant, slight latch on it, and the resistance it calls a short is at a good level.

Loads of other meters have scratchy, delayed buzzers, or pass far too high a resistance.

Re: the floating. Most meters that claim to float only do so without probes and strap attached.