EEVblog #372 - Fluke 27 Multimeter Review & Teardown

[DarkPrince]

[george graves]

According to this:  http://reviews.ebay.com/Fluke-Meters-Models-and-Series-main?ugid=10000000007478323

The real military version of the Fluke 27 FM is a true RMS meter.

UPDATE!!!  To every rule, there are one or more exceptions.   There is at least one exception to this rule. One of E-bay's expert meter sellers has informed me that the Military version of the Fluke 27, the 27/FM is a true RMS meter.   (The "non military" 27 does not have the True RMS feature.)   This is such a rare case that the Fluke representative that answered my question did not know that the 27/FM was a true RMS meter!    So, the 27/FM is better, because it has the "true RMS" feature.  Please see my section "TRUE RMS" in my  main guide (linked)

FURTHER UPDATE!!! Recently, the US government has begun selling newer Fluke 27s as surplus.  These look like civilian Fluke 27s - The LCD bezel is printed "Fluke 27,"  but  they have a label on the back that states "Fluke 27/FM."  These are NOT true RMS meters.  As far as I know, only the meters with "Fluke 27/FM" printed on the front of the meter (LCD surround)  are true RMS.  (see my sub- section on Rugged Types of meters.  Also linked below)

[DarkPrince]

Sorry Dave if you wanted to post the thread but I had seen the video on YouTube already. Anyway nice video and it does make it very tempting to try to 'hunt' for one. Eventually, probably will do so. I remember those style resistors, always fun. Had a kit in highschool that had resistors in that form. Awesome.

[Rutger]

Love the new/old stock. It looks brand new. Like the review, went online to ebay and found the same ebayer selling I think the same series (serial number very close), but no buy now option. I did put in a bid for $ 40, but they wanted $ 85 now so I don't think they will accept my offer.

[EEVblog]

The guy I bought from had several in stock at $40 But It Now.
Should have bought them all!

Dave.

[Excavatoree]

Crap - now I've got to see if my newest one is Cat III rated, and, if not, I'll have to get one that is and compare.

Great review Dave!  I'm glad you changed your mind!!!  (remember that E-mail from a while ago?)

EDIT:  Mine's just like Dave's - cat III rated.  I checked the input circuitry from an older one, and it's almost identical.   

Also, I've been known to leave one of mine turned on for weeks at a time - I forget to turn it off.   I can verify the battery life.

As I've said before, I really like these meters, and they are a great buy.

[EEVblog]

Great review Dave!  I'm glad you changed your mind!!!  (remember that E-mail from a while ago?)

I don't recall?

EDIT:  Mine's just like Dave's - cat III rated.  I checked the input circuitry from an older one, and it's almost identical.   

Thanks for the confirmation.

Dave.

[iloveelectronics]

For 2 bucks more than this one I think Dave has done okay

http://www.ebay.com/itm/FLUKE-27-FM-MULTIMETER-27-/120663477839?pt=LH_DefaultDomain_0&hash=item1c181a8e4f

[Rick]

The guy I bought from had several in stock at $40 But It Now.
Should have bought them all!

Dave.

He may still have grey ones but they may not look brand new like this one. They need to check with him.

[EEVblog]

http://www.ebay.com/itm/FLUKE-27-FM-MULTIMETER-27-/120663477839?pt=LH_DefaultDomain_0&hash=item1c181a8e4f

"Slightly used"!

Dave.

[tom66]

http://www.ebay.com/itm/FLUKE-27-FM-MULTIMETER-27-/120663477839?pt=LH_DefaultDomain_0&hash=item1c181a8e4f

"Slightly used"!

Dave.

How does one do that to a meter?
Take it canyoning like you did?

[Bored@Work]

How does one do that to a meter?

Military.

I didn't have to look at the seller's name to know where it was coming from. That seller is regularly discussed her for the abominations they offer.

[Tooms]

Hi guys

I have the older Fluke 27 there is before the one Dave have.

Here is an link to page with images of my Fluke 27

http://www.tooms.dk/Download/eevblogforum2/fluke27image.html


Tooms

[Excavatoree]

Hi guys

I have the older Fluke 27 there is before the one Dave have.

Here is an link to page with images of my Fluke 27

http://www.tooms.dk/Download/eevblogforum2/fluke27image.html




Tooms

Now that's what I call a nice, complete set of pictures.

[Rick]

By the way there are full yellow Fluke 27's rated Cat III. One of mine is cat III actually. This is the relatively good one. The other has its LCD darkened. I am thinking how to sort it out (any suggestions?). Either by buying a "for parts/not working" item and extracting the LCD or cleaning the LCd but I doubt it will solve the problem however I am sure the contacts need cleaning anyway.
The right hand one on the second pic is obviously an older model... I have not received them yet. May be tomorrow.

[Excavatoree]

By the way there are full yellow Fluke 27's rated Cat III. One of mine is cat III actually. This is the relatively good one. The other has its LCD darkened. I am thinking how to sort it out (any suggestions?). Either by buying a "for parts/not working" item and extracting the LCD or cleaning the LCd but I doubt it will solve the problem however I am sure the contacts need cleaning anyway.
The right hand one in the second pic is obviously an older model... I have not received them yet. May be tomorrow.

Be sure to take them apart and check - I've seen the plastic lens go dark, but never an LCD itself.   Unfortunately, it's part of the front case and can't be easily replaced.  I've got one or two that are darkened a bit, maybe as much as that one, I can't remember.

Parts meters are difficult to find - mainly because they keep working!  I thought I had a parts meter, but after I changed all 5 MOVs, it works fine and is still in spec.   I've seen LCDs on E-bay, but they are rare.  I've never had to replace an LCD or the zebra strips on any of my many 8025/25/27s.

[Rick]

Be sure to take them apart and check - I've seen the plastic lens go dark, but never an LCD itself.   Unfortunately, it's part of the front case and can't be easily replaced.  I've got one or two that are darkened a bit, maybe as much as that one, I can't remember.

Parts meters are difficult to find - mainly because they keep working!  I thought I had a parts meter, but after I changed all 5 MOVs, it works fine and is still in spec.   I've seen LCDs on E-bay, but they are rare.  I've never had to replace an LCD or the zebra strips on any of my many 8025/25/27s.

There are currently LCD's sold for other more recent Fluke models. That guy also sells spare parts according to what he told me.
But anyway if it s not the LCD it is good news. May be I can try to cut out carefully the plastic lens and replace it with something else, a similar thin transparent piece of plastic ? Or simply carve the visible part of the plastic lens to improve the visibility...

Another thing I would like to ask is: may I use thinner (just a drop) to remove the labels? Does it harm the outer plastic cover of the multimeter?

[EEVblog]

I have the older Fluke 27 there is before the one Dave have.
Here is an link to page with images of my Fluke 27
http://www.tooms.dk/Download/eevblogforum2/fluke27image.html

Hmm, noet the extra M205 glass fuse. I wonder what that is for?

Dave.

[tom66]

I have the older Fluke 27 there is before the one Dave have.
Here is an link to page with images of my Fluke 27
http://www.tooms.dk/Download/eevblogforum2/fluke27image.html

Hmm, noet the extra M205 glass fuse. I wonder what that is for?

Dave.

Very odd. It looks to be in series with the with the larger fuse. Perhaps some kind of dual-characteristic desired? Seems like a bodge to me, but too much of a safety thing to be a last-minute thing.

[retiredcaps]

The right hand one in the second pic is obviously an older model.

The one on the right looks like it has 0L "slanted" whereas the one of the left is "upright".  I have a Fluke 27 (grey/charcoal) and it has the "slanted" 0L.

I also notice that when it is set to resistance, the 0L looks like it is flickering as described in this thread

http://www.flukecommunity.com/forums/showthread.php?t=3458

I tried to respond, but I have been in the moderator's approval queue for 4 months now.

[retiredcaps]

Hmm, noet the extra M205 glass fuse. I wonder what that is for?

My Fluke 27 grey/charcoal has that extra fuse as well.

[Excavatoree]

I'm no fuse expert, I can only guess why they would put a  630 ma glass fuse (rated at 250v) in series with the 3 A 600V fuse.   Were the larger fuses not available in that small a range?   Did they want 630 ma protection for the ma range, but want the larger fuse for situations where the glass fuse may not work?  Or was it supposed to be the ceramic 630 ma fuse?  I'd like to get the answer.

Rick:
I'm not sure about what to use to remove the label without damaging the meter.  My worst label was OK considering the rest of the meter, I've never replaced one.   Do you mind telling me the seller's name?  I always need parts.

There are two different LCDs,  as there are three for the 70 series.   The two 27 types are interchangeable.  (The early two 70 series types are interchangeable.)  I'm guessing they were trying for a "more modern appearance." 

If the LCD only flickers in the ohms range, check the MOVs and the protection resistor.   It's been awhile since I've seen this on a 27.

On one or two occasions, I've had to change the board with the micro on it - I guess I could have just changed the chip, but I'd have had to take one off another board, so why not change the whole board?

[Rick]

The right hand one in the second pic is obviously an older model.

The one on the right looks like it has 0L "slanted" whereas the one of the left is "upright".  I have a Fluke 27 (grey/charcoal) and it has the "slanted" 0L.

I also notice that when it is set to resistance, the 0L looks like it is flickering as described in this thread

http://www.flukecommunity.com/forums/showthread.php?t=3458

I tried to respond, but I have been in the moderator's approval queue for 4 months now.

Is it flickering or just the segments which are faded ?

Excavatoree: it is this guy : http://www.ebay.com/usr/rickthompson602t ,  the same who sold a fluke 27 to Dave.
Thank you for the advice.

[Monkeh]

I'm no fuse expert, I can only guess why they would put a  630 ma glass fuse (rated at 250v) in series with the 3 A 600V fuse.   Were the larger fuses not available in that small a range?   Did they want 630 ma protection for the ma range, but want the larger fuse for situations where the glass fuse may not work?  Or was it supposed to be the ceramic 630 ma fuse?  I'd like to get the answer.

Sacrificial fuse. Anything it can't cope with, the big one will handle. Anything it can cope with, saves you a very expensive fuse.

[baljemmett]

Hmm, noet the extra M205 glass fuse. I wonder what that is for?

My Fluke 27 grey/charcoal has that extra fuse as well.

As does my charcoal Fluke 25.  Which I just dismantled to take some photographs of the display/digital board to compare to Dave's (it's too late to pull it any further apart before bedtime!), before I noticed Tooms had already posted a much more comprehensive set.  The digital board is identical between the 27 and the 25, but I don't plan on drilling any holes in the front of mine to get the two extra buttons!