EEVblog Electronics Community Forum

EEVblog => EEVblog Specific => Topic started by: PetrosA on February 28, 2010, 05:24:08 pm

Title: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: PetrosA on February 28, 2010, 05:24:08 pm
So far, not a bad review, Dave.

I have to say, the IP rating and drop rating on this meter seem almost gimmicky to me as an electrician (especially considering the crappy gasket), and a whole slew of "Who wants his meter?" jokes came to mind, like "Hey guys, Sparky got shocked, fell off his ladder and died, but his Fluke is still ticking, so who want his meter?" The only sense I can see in the IP rating is if the meter gets dropped into water by accident since no electrician worth their salt would take the risk of testing open mains voltage in the rain or with a hose pointed at them unless they work for a utility company.

The continuity tone is actually one step down in pitch from the 87V, but that's a minor detail :)

Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: rossmoffett on February 28, 2010, 05:47:43 pm
There's also the accidental side of things, people who do field work might accidentally leave it out in the bed of a truck and then it rains, or maybe they're on a ladder and can't find a secure place to put the meter, or it could fall out of the truck, etc. etc.

Generally though the people I've worked with treated their expensive equipment like their babies, because they'd paid for one before.   :D
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: PetrosA on February 28, 2010, 11:44:44 pm
There's also the accidental side of things, people who do field work might accidentally leave it out in the bed of a truck and then it rains, or maybe they're on a ladder and can't find a secure place to put the meter, or it could fall out of the truck, etc. etc.

Generally though the people I've worked with treated their expensive equipment like their babies, because they'd paid for one before.   :D

I agree. It would be rare to find someone who paid for a tester like that themselves and would be careless with it. We don't make that much money ;)

For all but torrential rain though, IP 67 is overkill in general use. I doubt a regular tester is going to get damaged beyond repair by water, even if it was submerged (except maybe salt water). Just dry it out before using again.
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: rossmoffett on February 28, 2010, 11:47:37 pm
For all but torrential rain though, IP 67 is overkill in general use. I doubt a regular tester is going to get damaged beyond repair by water, even if it was submerged (except maybe salt water). Just dry it out before using again.

I was thinking the same thing as I was watching it, I have a hard time imagining situations where an 87 wouldn't take pretty much the same abuse.  Granted, it doesn't have all of the O-rings but not much water would make it in.
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: EEVblog on March 01, 2010, 08:13:52 am
The most impressive (and useful) thing about the meter for me is the ruggedness, not so much the waterproofing.

Having just done most of my drop and abuse testing, I must say I'm very impressed at what this meter can survive!

The waterproofing and buoyancy might seem a gimmicky for most, but you have to remember Fluke sell zillions of these to the military, and in those fields you don't just measure stuff when the conditions are hunky-dory.

But even in factories and environments I've worked in, it was not uncommon to get oils and liquids spilled on a meter. So I can think of lots of places such a rugged waterproof meter would be handy. Fluke are on a real winner I think, it ain't no gimmick, you can bet your bottom dollar it meets a real market need.

Dave.
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: PetrosA on March 01, 2010, 02:52:34 pm
The most impressive (and useful) thing about the meter for me is the ruggedness, not so much the waterproofing.

Having just done most of my drop and abuse testing, I must say I'm very impressed at what this meter can survive!

The waterproofing and buoyancy might seem a gimmicky for most, but you have to remember Fluke sell zillions of these to the military, and in those fields you don't just measure stuff when the conditions are hunky-dory.

But even in factories and environments I've worked in, it was not uncommon to get oils and liquids spilled on a meter. So I can think of lots of places such a rugged waterproof meter would be handy. Fluke are on a real winner I think, it ain't no gimmick, you can bet your bottom dollar it meets a real market need.

Dave.

I absolutely agree that ruggedness is a "deciding factor" kind of feature. Let me qualify my "gimmicky" comment to give you a better understanding of where I'm coming from. Here in the US, Fluke has traditionally been sold exclusively through supply houses, industrial supplies, specialty test equipment suppliers etc. It was not the kind of thing you could go to your local hardware store and buy and because of that, their "marketing" style was geared towards professional users like us. In recent years they've started selling their products through Sears (a large consumer-grade tool store), and a number of hardware and big garden center/residential hardware stores like Home Depot and Lowes. Unfortunately, many professional grade brands that have gone that route have suffered visible and measurable drops in quality in an attempt to sell volume. I hope that this won't happen to Fluke, but when I see something like that waterproofing o-ring it just makes it look like their intent is to sell a gimmick, rather than a real advancement.
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: Veramacor on March 01, 2010, 04:06:24 pm
Dave also had a useful subliminal message for fanboys in the video at 15:53...





Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: EEVblog on March 01, 2010, 08:43:17 pm
Dave also had a useful subliminal message for fanboys in the video at 15:53...

LOL!
oops!

Dave.
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: EEVblog on March 01, 2010, 08:56:33 pm
I hope that this won't happen to Fluke, but when I see something like that waterproofing o-ring it just makes it look like their intent is to sell a gimmick, rather than a real advancement.

Well, I can assure you it works and it good enough for the intended job.
Maybe the trade-off was a full size traditional o-ring would have made the product even bigger than it already is.
I think they have done an acceptable job with the waterproofing.
In some ways I kind of see their method as an "advancement", in that they are able to achieve such good waterproofing using non-traditional techniques.

Of course it's not fully waterproof and water will eventually get in if you leave it under long enough. To do true waterproofing requires not only a quality o-ring and surfaces, but full grease application as well.
This is why I didn't bother doing traditional testing of the waterproofing by sticking it in static depths of water for long periods of time until it failed, I saw that as boring and kinda pointless. Instead I just had fun with it in a known tough environment and it survived without an issue, even with the pinched o-ring seal I found.

Dave.
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: PetrosA on March 01, 2010, 11:36:10 pm
I hope that this won't happen to Fluke, but when I see something like that waterproofing o-ring it just makes it look like their intent is to sell a gimmick, rather than a real advancement.

Well, I can assure you it works and it good enough for the intended job.
Maybe the trade-off was a full size traditional o-ring would have made the product even bigger than it already is.
I think they have done an acceptable job with the waterproofing.
In some ways I kind of see their method as an "advancement", in that they are able to achieve such good waterproofing using non-traditional techniques.

Of course it's not fully waterproof and water will eventually get in if you leave it under long enough. To do true waterproofing requires not only a quality o-ring and surfaces, but full grease application as well.
This is why I didn't bother doing traditional testing of the waterproofing by sticking it in static depths of water for long periods of time until it failed, I saw that as boring and kinda pointless. Instead I just had fun with it in a known tough environment and it survived without an issue, even with the pinched o-ring seal I found.

Dave.

You have a point there, Dave. I'm probably oversensitive to changes in marketing for the reasons I mentioned, but I should give Fluke the benefit of the doubt for now. I'll be awaiting part II of your review impatiently!

Thanks!
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: walterdelbono on March 02, 2010, 01:33:49 am


what an ugly component it seem like it's been written by hand...

jajaj...

Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: walterdelbono on March 02, 2010, 01:38:34 am

it's amazing when you start to think about all the things that could fail in the production process of a product like this...

:)
Title: SAFETY NOTE
Post by: PetrosA on March 02, 2010, 02:41:03 am
I saw in the comments to the video that someone (Johannes) suggested testing the meter under water. I'm sure Dave won't do anything that dangerous, but for any of you who are maybe less well versed in the dangers of electricity, hooking up a multimeter to any kinds of voltage above approx. 30VAC or 45VDC with the meter submerged or even floating would be a very dangerous thing to do. Even this multimeter with it's IP67 rating would be a hazard if the test leads were energized in water, since the rating doesn't apply to the test lead jack, only to the INTERIOR of the meter itself. Dangerous current could leak into whatever water container you "tested" this in. All kinds of nasty consequences could ensue depending on the mineral levels of the water you placed the meter into. Just DON'T DO IT.
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: EEVblog on March 02, 2010, 08:26:53 am
In practice the water actually confuses the optical input alert function, so it actually thinks you have the probe plugged into the AMPS jack and it beeps and flashes at you (but still reads).

I've been told Fluke disable the optical sense circuit when displaying the meter at trade shows where they show it working underwater.

Yes, all safety ratings are gone out the window once it is immersed.

Dave.
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: Veramacor on March 02, 2010, 01:55:46 pm

I have to agree that multimeters and water don't mix!  Any sailors here?

Apparently this story is true.

http://www.darwinawards.com/darwin/darwin1999-50.html

The lethal 9 Volt!

Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: Pradipta on March 03, 2010, 07:09:59 pm
IP67 translates to IP6x: Totally protected against dust and IPx7: Protected against the effect of immersion between 15cm and 1m
If you have not already noticed, the Fluke official demonstration video shows 'the water actually confuses the optical input alert function, so it actually thinks you have the probe plugged into the AMPS jack and it beeps and flashes at you'.
I much prefer the sealing strategy of the GM Metrahit, though it does not boast IP rated protections.
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: jimmc on March 03, 2010, 09:12:53 pm
Warning off topic rant...

What a load of rubbish that Darwin award is.
Looking at the circuit of a Simpson 260 here http://www.simpson260.com/downloads/simpson_260-6p_theory_of_operation.pdf
The 9 volt battery is only used on the Ohms x 10,000 range and then there is at least 114k in series with it.
So the maximum current is limited to 9/114,000 = 79uA !!! Not the 90mA they claim.

Jim
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: Ferroto on March 04, 2010, 04:44:19 pm

I have to agree that multimeters and water don't mix!  Any sailors here?

Apparently this story is true.

http://www.darwinawards.com/darwin/darwin1999-50.html

The lethal 9 Volt!



I just emailed Jamie Heinemann (http://en.wikipedia.org/wiki/Jamie_Hyneman)
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: Simon on March 06, 2010, 08:32:33 am

I have to agree that multimeters and water don't mix!  Any sailors here?

Apparently this story is true.

http://www.darwinawards.com/darwin/darwin1999-50.html

The lethal 9 Volt!



Yikes never thought my multimeter could kill someone
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: jahonen on March 06, 2010, 09:52:09 am

I have to agree that multimeters and water don't mix!  Any sailors here?

Apparently this story is true.

http://www.darwinawards.com/darwin/darwin1999-50.html

The lethal 9 Volt!



Yikes never thought my multimeter could kill someone

If you have a multimeter with a 9 volt battery and another one, can you measure the current it puts out in ohms range? I'm just curious.

Regards,
Janne
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: EEVblog on March 06, 2010, 01:06:33 pm
The torture test of the 28-II is complete and the edited video is in the can, shot over two weekends. Should be up tomorrow. Boy it was certainly FUN!
And I got out of the lab for a change!

Dave.
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: mzacharias on March 13, 2010, 01:05:22 pm

I have to agree that multimeters and water don't mix!  Any sailors here?

Apparently this story is true.

http://www.darwinawards.com/darwin/darwin1999-50.html

The lethal 9 Volt!




Doesn't look right to me. A Simpson Series 6 and above using a 9 volt battery only uses it for the Rx10K range, resulting in a short-circuit current in the low microamps. Even a 5P military version only uses it's 15 volt battery for the Rx10K range.
Now the 1.5 volt battery could maybe provide up to 15 or 20 milliamps through 100 ohms internal body resistance depending on the position of the ohms zero potentiometer.
That could conceivably cause fibrillation in a sensitive individual...


Mark Z.
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: Kiriakos-GR on April 06, 2011, 01:58:37 pm
Quote
waterproofing o-ring


Is there any info about the time frame that those o-ring should be replaced , or serviced ?

Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: tekfan on April 17, 2011, 08:55:00 pm

I have to agree that multimeters and water don't mix!  Any sailors here?

Apparently this story is true.

http://www.darwinawards.com/darwin/darwin1999-50.html (http://www.darwinawards.com/darwin/darwin1999-50.html)

The lethal 9 Volt!


Doesn't look right to me. A Simpson Series 6 and above using a 9 volt battery only uses it for the Rx10K range, resulting in a short-circuit current in the low microamps. Even a 5P military version only uses it's 15 volt battery for the Rx10K range.
Now the 1.5 volt battery could maybe provide up to 15 or 20 milliamps through 100 ohms internal body resistance depending on the position of the ohms zero potentiometer.
That could conceivably cause fibrillation in a sensitive individual...


Mark Z.

When I was about 5, I once stuck two probes in the wall outlet (Europe so 230 VAC) trying to get a model train to go. Then I touched the probes. One in each hand. I received a very nasty shock but immediately let go and everything was OK.

More recently I cut my finger somehow and the alligator clips going from the 30V, 3A power supply touched the wound. It hurt like someone was rubbing salt into my finger but no smoke or grilled sausage finger.
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: Kiriakos-GR on April 18, 2011, 02:37:41 pm
Well I have to admit publicly  :)  that I have start to love my Fluke 28 Series II .
I have it for few months, and it is an worthy asset.

But as single unit , its not perfect with out the extra Fluke probe set,
known as "Pin & Socket Adapter Set" TP88
(http://www.tequipment.net/ProductImages/Fluke/TP88_mid.jpg)

With out it , troubleshooting heavily populated PCB's with mixed in height components ,
or measurements on tiny metal contacts , are very difficult to do.  

The only thing that bothered me in action, was the "auto backlight off timer",
but at the end, if you educate your self with the information of how to disable it,
this problem ends . :)

And I will totally agree with Dave, about the use of the free space on the tilt bail,
that it must be used as location for writing on it , one quick reference about the Power-up options.
Or else you have to remember all of them by hart.
Or you must always carrying with you, an copy of the page 14 of the Users Manual .

Also the Fluke 28II , damaged my internal enthusiasm about multimeter's ,
like seeking all the time the market, for the ideal DMM.
Simply because it is the ideal DMM for me.

And if there is a point that I will agree with Dave 101%,
is that the magnetic hanger, it must become an standard supplied for "free" accessory.  

It did prove the value of it as idea, when I had to troubleshot one small electrical problem on my motorcycle.
And I did use the hanger system TPAK, not the one with the magnetic end, but the second belt "the loop hanger" ,
so to mount the 28II at the handle bar, and by this positioning I had it next to me , with out interfering with the limited space for tools around one motorcycle.

And so if the magnetic hanger works for metallic panels ,
and the loop hanger for pipes. ( add to this list and the handle bar of an motorcycle)

Well as synopsis , the 28II can :
Fly  -  ( ToolPak  ( TPAK) Magnetic Hanger &  loop hanger)
Swim - float   ( IP67) + Fluke design
Fall - drops    ( IP67)
Shine- glow at dark   ( buttons emitting light with no electricity)  
Better beeper than the 87V ( my opinion - my ears like it more)
Micro electronics   ( always with the use of TP88 )


Another thing that I like it on the 28II over the 87V ,
was that tilt bail , looks identical with the 87V but the 28II has more weight,
and more square bottom base, and are lot more stable about standing in the bench.

And so this base that I did for the 87V, has less importance for the 28II  https://www.eevblog.com/forum/index.php?topic=455.0 (https://www.eevblog.com/forum/index.php?topic=455.0)

And the bottom line is that only my imagination can stop me,
from other possible ways of using this meter.

After six months + few days of ownership,
I admit it, yes the 28II it is an object that deserves love .  ;D
( as everything worthy )


(http://img9.imageshack.us/img9/7302/28ii.jpg)
(http://img816.imageshack.us/img816/1479/28iithereturnboxed.jpg)


EEVblog #64 - Fluke 28 Series II Multimeter Review & Teardown (https://www.youtube.com/watch?v=vkYm021p5qk#ws)
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: saturation on April 18, 2011, 03:46:29 pm
If Fluke gives no recommendation, the ASTM estimated shelf life [ i.e., just left in storage conditions] can be used assuming they are not subject to wear such as abrasive forces [ i.e., like used as seals in pistons] or harsh environments like sunlight, ozone, or other chemicals.

http://www.oringsusa.com/html/shelf_life.html (http://www.oringsusa.com/html/shelf_life.html)

If you're not sure of the material, most low cost general purpose o rings are buna-n types.

For the Fluke 28II it looks like its in near ideal conditions for o-ring lifespan, ~ 15 years.


Quote
waterproofing o-ring


Is there any info about the time frame that those o-ring should be replaced , or serviced ?


Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: Kiriakos-GR on April 19, 2011, 12:28:45 pm
Thanks S. for the tip .

It looks that there is no reason to puzzle my self about it. ( o ring )

But I found a new puzzle ...  ;D

It looks that the continuity response from the latest version of the 28II that I got,
to not be that fast, as is in the video of Dave.

I cleaned the leads, but no improvement, my other though are to check the batteries condition.
If the not topped batteries , has an negative effect in the speed of the continuity response ,
is something that i need to find out, so to stop thinking about it.  :)

 
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: saturation on April 19, 2011, 01:30:37 pm
You're welcome K.  A problem with failing O rings is that when the O ring finally fails, you'll notice it when the internals of the device it protects also gets wet, and it could ruin the gear.

Since most DMM aren't as waterproof as the 28II, this issue doesn't concern most of us.  But it would pay to find a source for the o rings and change them every 7 years,  that's hard to remember!  What I do with my marine grade gear is write the expire date on thin scotch tape placed on inside of the battery case to protect it from water and the environment.  Then change the tape and put a new date when you get a new o ring.  Since the batteries will last a long time but unlikely more than a typical battery shelf life of 5 years, you'll see the date every battery change, to remind you, and still give you a large margin of safety.

Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: Kiriakos-GR on May 07, 2011, 03:16:53 pm
Additional info about continuity response :

Well the truth is that I got fooled , because I did my continuity test on the diode mode,
and not at the ohms range !!
At the ohms range the continuity response are lightning  fast as shown on Daves video.

What it was not shown on the video, was how the display back light works out in total darkness,
and this info is useful to the electricians who works at dark cabinets ,
or they work with auxiliary lighting , so to repair the main lighting system !!

The amazing part , are that the buttons on it,  has their own back light,
and so in total darkness are both visible and usable  (display + buttons).  :)

Picture

   
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: Mechatrommer on May 07, 2011, 03:56:01 pm
Well the truth is that I got fooled , because I did my continuity test on the diode mode,
and not at the ohms range !!
luckily you didnt get fooled (or killed?) by measuring V on A range ;D just a joke
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: Kiriakos-GR on May 07, 2011, 04:59:18 pm
Well the truth is that I got fooled , because I did my continuity test on the diode mode,
and not at the ohms range !!
luckily you didnt get fooled (or killed?) by measuring V on A range ;D just a joke


Well its harder to get killed in Europe , we do not have high voltage sources of 600V or 1000V in our industry . :P
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: turkey1987 on May 07, 2011, 11:43:16 pm
Hello,

Has anyone tried with their Fluke 28 II to do a continuity test (with continuity beeper) and the backlight on max (second brightness)?

When I do this with mine, it seems to get a low battery alarm (small battery icon in the top corner)

I am using standard akaline batteries, which measure 1.588vdc.

I have tried using a brand new set which measure 1.613vdc


I was just wondering if anyone else has experienced this problem?

Also to note, I returned my meter cause of this problem and the new meter reproduces the same problem.

Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: cuban8 on May 08, 2011, 08:58:57 am
Yup, same here with a new set of batteries.
Doesn't affect the function of the meter, so I don't really care.
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: turkey1987 on May 08, 2011, 09:11:38 am
Yup, my meter seems to function properly and have not had any problems with it.

I was just curious to see if this is a common issue, or possibly a bad batch on my part.


My next test is to use the energizer lithiums, which naturally have a higher voltage then the akalines

Have no idea yet, will have a look.

Thanks
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: Kiriakos-GR on May 08, 2011, 11:09:16 am
Hello,

Has anyone tried with their Fluke 28 II to do a continuity test (with continuity beeper) and the backlight on max (second brightness)?

When I do this with mine, it seems to get a low battery alarm (small battery icon in the top corner)

I tested my 28II, in both ohms and Diode mode.
With the back light on ,
and I have to say that there is not present, this minor software glitch.
And so it behaves as expected.

I have still inside the batteries that came with it from the factory .

The truth is, that the meter that I own , came to me directly from the Fluke factory (USA),
about seven months back.
And so it is an very fresh batch.  

If it bothers you that much, send it to Fluke,
they will do their best, so to help you.  :)

( But it will take 2-3 weeks until to get it back)  ( Europe )

Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: turkey1987 on May 08, 2011, 10:39:19 pm

Hello,

Just as a comparison,

My meter works fine in ohms and diode test. Each work fine on their own. Backlight max by itself and continuity beeper test by itself.

But the problem only arises when I activate both beeper (ohms then press continuity beeper mode) and max backlight.
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: Kiriakos-GR on May 09, 2011, 01:37:13 am
Yes , I did follow your instructions about the sequence :

1) Range switch to Ohms
2) Activating beeper
3) Back light display to level 2.
4) testing continuity ( random contacts of the leads )

And there is no problem , works as it should.
The battery indicator does not show up.   (  There is no low battery alarm )

And my advice to you are to use your warranty plan.
So to send the 28II back to Fluke, for inspection.

Regards ..  



  
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: turkey1987 on May 09, 2011, 01:45:24 am
Hello,

I have spoken to fluke and my supplier,

They have tested, their fluke 28 stock and they seem to have the same problem and are investigating at the moment.

Also to note, this is my second fluke 28.

But thank-you for the comparison, I don't mean any disrespect.
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: turkey1987 on May 09, 2011, 05:54:39 am

Hello Kiriakos-GR ,

Out of curiosity, what brand of AA batteries are you using?

And are they standard akaline?

Possibly fluke put lithium batteries in yours ?

Its okay if you have never opened your meter and you dont know, dont open it on my regard

Thankyou
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: Kiriakos-GR on May 09, 2011, 12:29:39 pm
There was no way to help you , or any one else,  with out opening the DMM.  :)

Even so they are common AA Alkaline's .
Brand : Energizer
Type :  LR6 - AM3 1.5V

They are made in USA ( St. Louis )

Expiration date : 03-2017

That's it .. nothing magic or special on them.

Enjoy the view ..  :)

Just tested the batteries with my professional battery tester ( with load) .
Cell 1 = 90% = 1.45 v
Cell 2 = 90% = 1.45 v
Cell 3 = 80% = 1.44 v

Active since 7/10/10   d/m/y
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: turkey1987 on May 09, 2011, 08:57:21 pm

Thank-you for your help,

Well I have reached a point where I must wait for fluke to decide.

I have been asked where does it say energizer lithium batteries for mining approval.

I just looked it up, but I think iam wrong. It says energizer e91, on the rear of the 28. Which I thought was the code for lithium, but possibly could just be the standard alkaline battery. So a correction on my behalf.

Thank-you

Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: gobblegobble on May 09, 2011, 10:19:19 pm
I just looked it up, but I think iam wrong. It says energizer e91, on the rear of the 28. Which I thought was the code for lithium, but possibly could just be the standard alkaline battery.

E91 is DIN term for AA alkaline cell unless I'm mistaken. Energizer's Lithium cells are L91, close but still as far as A3 is from M3 (for those who like car references). :D
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: turkey1987 on May 10, 2011, 12:01:29 am
I would much prefer an M3 :)

But Yup thanks for the correction.

Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: Kiriakos-GR on May 10, 2011, 08:40:12 am
Hey  @turkey1987 ,
I have for you one last question ,
do you have handy the first 5 digits of your serial code ? ( in total 8 )

I need that, just of curiosity .. 

Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: turkey1987 on May 10, 2011, 11:17:29 pm
Hey Kiriakos-GR,

I have sent you a pm.

Regards

Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: Kiriakos-GR on May 11, 2011, 12:40:03 am
Today I discovered one true inconvenience or issue ,
That it must be noted to FLUKE.


At the Ohms range  0-600 Ohm  ( manual range )
If you activate the High Resolution ( 20.000 counts ),
If you try to measure any resistor that is more than 199 Ohm ,
The DMM shows in the screen  OL  and the bar graph goes to full .
Exactly the same indication, as it does when you do not perform any measurement at all in Ohms range .

This could easily fool you, and make you to believe, that you have at hand one bad resistor !!!

Maybe is just only me, who believes that this is an inconvenience or issue,
But what I would call as logical , would be, that at the end of the road of the 20.000 counts in the manual modes,
It should described with any other symbols than the OL .

I can hardly call as Bonus, that at the named  0- 600  Ohm range the DMM can read as max  650 Ohm at the normal resolution.


Another one called as inconvenience or issue,
Could be one detail that I found today ,
By reading one Application Note ( PDF) of Fluke named as : Low ohms measurements you can trust
It describes how to make one quick test to ohms range , so to verify that your meter reads accurate Ohms.

The Fluke 87 has an internal 1K precision resistor.
Test your meter against this by connecting a test lead from the V-ohms jack to the
microA/A jack while the meter is in Ohms mode.
Don’t forget to zero out that test lead, first —simply put the lead between the
v-ohms and COM jacks and press the Relative button .

http://www.myflukestore.com/crm_uploads/low_ohms_measurements_you_can_trust.pdf (http://www.myflukestore.com/crm_uploads/low_ohms_measurements_you_can_trust.pdf)

Ok , so far so good , but if I zero out the leads , the relative mode will stop the auto ranging .
If I zero out with auto ranging at  0-600 Ohms, there is no way to measure 1K , I will get OL !!
The same OL that I get with disconnected leads !!

As long the 87V and 28II, are totally identical, they share the same issues in Ohms range.

And so, yes FLUKE you have to do something about that,
And update – rewrite  your documents too.
  
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: saturation on May 12, 2011, 03:03:03 pm
I see that that's unfortunately what to expect though.  At normal resolution its 6000 count, at high resolution its 20000 count, so when switched to this mode its maximum reading is 199.99 in the 600 ohm scale.

The Fluke 87V does this stuff too in any range besides ohms, such as volts, and it switches immediately to manual mode, although you can force it to auto at hi resolution.

Note, the 87V spec sheet states the accuracy is unchanged since the uncertainty of the last floating digit increases 10X when using 20,000 count, so that last digit is no better than the low resolution mode.  However, in practice, it is accurate when its stable when I compare it against the HP 3456a.  So use the extra resolution with a grain of salt.


Today I discovered one true inconvenience or issue ,
That it must be noted to FLUKE.

..

As long the 87V and 28II, are totally identical, they share the same issues in Ohms range.
..
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: Kiriakos-GR on May 13, 2011, 06:45:59 pm
Well I could live happily by knowing from the start the limitations of the 20.000 counts on both 87V & 28II .
( If they was on paper ,  as NOTE about the 20.000 counts resolution )

But I do get partially upset , when I find out about them, by my self !!

Examples :
1) The 199 ohms at the 600 scale  ( OL indication with out measuring ... OL again at the end of the 20.000 counts  (200 ohms? ) = confusion
2) On DC after the 20V, the High resolution goes normally off , but in order to get active again , the voltage must drop to 16V  and not to 19V !!
3) The display refresh rate at the 20.000 counts, are limited to one time per second !!  ( Normal resolution = four times )

Is those findings critical ? so to upset an new buyer ?

Yes and No.

Yes .. if you are an electronics engineer.
No .. If you are an Industrial Electrician , who will consider the amount of counts ,
as one less important function.

I stand in the middle of the two world's , like touchy electronics and industrial motors ,
and probably this is why it bothers me.   ;D

About the 28 II , even after those nags of my , I still consider it as top meter .
An true honest companion, accurate and hard to be killed.  ;)

But the throne of 87V , it is not that secure.

Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: saturation on May 13, 2011, 07:05:46 pm
Yes, K, this is the point were Agilent DMM can move in !

Well I could live happily by knowing from the start the limitations of the 20.000 counts on both 87V & 28II .
Title: Re: EEVblog #64 – Fluke 28 Series II Multimeter Review & Teardown
Post by: Kiriakos-GR on May 13, 2011, 07:57:55 pm
Hi S.

Personally I do not care, who does plans to move in.  
Trust and confidence , needs years to be build ed.
( and I count about 14 months, since the time that I touched something branded as Fluke)

And now I will say something, that helps my psychology as professional ,
when ever I feel irritated about the above issues, on those Fluke DMM's,
I just watch the 100$ shootout video ..
And I am saying to my self ... Thanks God that I do not have any of them. !!   :D