EEVblog #64 - Fluke 28 Series II Multimeter Review & Teardown

hi welcome to the EEV blog an electronics engineering video blog of interest to anyone involved in electronics design I'm your host Dave Jones hi it's equipment review time again and yes it's another multimeter and yes it's another fluke but I'm very excited about this one because thanks to fluke Australia I've got the brand spanking new fluke 28 series - hot off the production line let's check it out so what is the Fluke 28 series - well it's an upgrade to the original fluke r-27 if you remember the fluke 25 and flew 27 they've been around for yonks our decades I think really top meters super rugged if they're actually the most rugged meters that fluke make the Fluke 25 and flew 27 um this is the new model this is available in two models the fluke 27 series - but this is the fluke 22 the hi-spec fluke 28 series - so it's taken a long time for flute to upgrade those those famous 27 25 and 27 models and what they're chosen to do this time instead of had the same thing they've decided to copy the fluke 87 function and functionality wise this is basically check them out side by side this is identical functionality to the fluke 87 absolutely identical and every everything's exactly the same basically except it's bigger as you can see it's actually check out the thickness of it it's there's a big difference in the thickness and and the size and the weight is slightly more in this one and it's heftier but it's basically a copy of the 87 a super duper rugged version as if the 87 wasn't rugged enough already they've gone and made this one waterproof and are 3 meters drop resistant let's check it out and you know what we say here at the eevblog don't turn it on take it apart now to get it the fuses in the back you're going to take off this huge plate which goes the whole length of the meter there's six Phillips screws on there and let's do that and see what's inside okay I've taken the cover off and fluke have got it right they've got metal threaded screws in the metal threaded inserts and as you can see its power from three double A batteries beauty no more 9-volt rubbish yes there's an o-ring there's a sort of a rubber o-ring around the outside of the holder like this so when you compress it on they've actually used a curved surface here which is quite which which makes it harder to get a seal on a curved surface than it does on a flat one so I'm not quite sure why they've curved it but dump I'm sure they've made it work and they've done extensive testing that the sealing actually works on the battery compartment now the fuse compartment down here it's got this nice funky little rubber boot on it and you peel it off like that and that's not the end of it you can't see the fuses yet there's a rubber boot which once again is compressed by the back cover when you screw it on forming a seal and then they've got this little cover here which pops off and bingo there's the HRC fuses brilliant design absolutely brilliant thumbs up now you don't actually have to take the battery cover off to actually um get the case apart you just take out these six screws here which are actually um they're threaded just like the old-style a fluke one so flew Kevin change their style of joining the case in you know twenty years or something they still use metal thread into plastic insert but it's talks it's a tea talks tea 10-bit I think it is so it's not a Philips so it makes it hard and then you've got these little rubber o-ring things which are inside each one of these ah feel actual um waterproofing so let's take it apart shall we it pulls open just like this feels like it it opens up and bingo check it out haha lovely now the battery contacts let's let's check those out there actually these sort of they're not I much prefer the ones that are soldered directly onto the board but they've gone something different here they've gone these contact ones which just make contact with the gold pads on the board and well I guess that can work just as well but um it's just different to what I was expecting I guess but check out the input circuitry ah isn't that sex on a stick boys and girls ladies and gentlemen here's a textbook example of how to design high voltage isolation slots and high energy isolation slots on a multimeter isn't it just brilliant check out those slots and if you notice the case over here all these large are these large like blast shields are designed to mate and go into and go into these slots down here so it separates the UM the DISA it separates the voltage input from the fuses and everything else fantastic flu could put so much work into that it shows why they're the number one maker of multimeters my hats off to the guys and girls at fluke who have designed this thing it's brilliant now this plastic cover here comes off with a single screw down here like this and as you can see you can't really see much of the circuitry there's some sort of some sort of um input or current sense circuitry over there there's the thick film resistor hybrid Network and there's another thick film resistor down here you've got your classic input protection stuff which again is um isolated from that with the blast shield and the high-voltage isolation slot this circuitry here is obviously the DC to DC converter from the battery they've got a poly switch here which is excellent to actually protect the battery and and the speaker day while the piezo transducer down here has got these little Springs integrated it really is quite high quality which make contact with the pads but they clear because apparently I've been told that these have though isolation and sorry not opto isolation but Auto opto detection of when you plug the probe into the jack so let's check it out and also there's the 10m current shunt as well that's quite well done actually a comment I'll make is that I'm quite surprised by these um these actual standoff standoff resistant networks in such a rugged high-end meter I kind of expected they to come up with like a surface mount version of these because if you impact this bang like that um this could potentially shear off but you know I've got to say that fluke know what they're doing so I'm sure they've tested it rigorously and you know vibrations not an issue and there's no resonant modes and things like that so um yeah you know we'll test that later but we'll take sort of a fluke so design opinion on that one now another thing I noticed when I took it apart is that the o-ring around the edge here let's see if we can focus on that looks this one's has got some damage there I'm not quite sure how or why that happened that wasn't me was sort of a bit the o-rings been a bit pinched but as you can see it's got a ring around right around the outside I actually expected a better I ring them that one but um I'm sure that fluke make it well and they've didn't make it designed it quite well and they've done their homework and as I've mentioned before in a previous review of flukes they've got these nice deep things that provides quite a hydraulic feel when you actually put it together as well as as well as actually containing any internal blasts if you overload it so it really is quite nice and these blast shields in the battery compartment it's just superbly designed I'm I really this is the best mode designed fluke I've ever seen okay let's take the board off I've taken out the six screws here plus the four screws on the on the input jacks and the board should just lift out like that too ah and there it is you can see the zebra strips for the LCD and this is the this is the board here isn't it lovely I'm not sure if you can read that but there's no surprise that's an msp430 processor with a whole bunch of once again 7/4 sorry our 4000 series logic a CD four oh six nine there's a linear technology part there and it all looks it all looks very lovely there's a fluke branded part right there so it and it looks excellent it really does and here is the here is the opto sensing for the input jacks there it is right there so that goes through the clear housing on the input terminal jacks as you can see there's one big plastic thing and it seems it seems really embedded in there so it's entirely waterproof the whole thing and you can't even get through the jacks so that's how they've waterproofed the input jacks it's very very nice I've taken the rain switch off here it was just the plastic clips on the back and as you can see there's the internal contacts and I'm sure that is that looks like excellent gold plating I'm sure it's very thick and first-class quality as you'd expect from a fluke one thing I noticed is that it's copyright 2008 fluke so they started on this design sometime in 2008 and interestingly its revision 9 PCB there it is their revision 9 which indicates that fluke have really um you know put a lot of effort and actually refine this before they entered production and the whole LCD assembly just lifts out as one integral thing like that very nice and yes everything really is the same between these two meters functionality specs and even the LCD check it out if you can see that it's hard to get it but they're actually identical LCDs and yes a display update speed is the same and the display as well four and a half digits 20,000 count is the same between the meters they haven't upgraded that at all there really and the only major differences as you can see are they instead of having the jacks for inline they've got them separated like that now and the buttons although the button layout is identical the type of button is actually changed but these ones actually a neat feature these ones I didn't like them at first um they're actually quite quite they're got a different look to them and over the funks not as easy to read on them ah but they actually glow in the dark I'm just taking this outside for a couple of seconds just to just to get some light into it and I'll turn the lights off and we'll see if we can see it yep you can you can see that they actually they actually glow it's really it's and that's just you know and that's not a LED thing there I actually got some florescent type material in there and that's really neat so not only is it identical to the 87 r-spec wise and functionality wise well if the price isn't too much different ever it's about a street price of about four hundred and thirty US dollars in eighty seven is about go you can get it for about three hundred and eighty or something like that so it's not that much more expensive really but you're getting a much more rugged meter for your money so if if you don't mind the extra size of it and slightly extra weight and the extra bulk and thickness well you know I mean it's probably not a bad choice to go for the 28 over the 87 so I won't really repeat all the stuff I love about the 87 and why it's my but my favorite meter and it's one of the best on the market and it's probably the most popular on the market this you know saw might go through the great features yes it's got point oh five percent plus one count basic DC volts accuracy point two percent on owns point two percent on current and it's got the famous type fluke touch hold min max radians got a temperature sensor it comes with a probe we'll check that out you know it's it's superfast it's super accurate it's super reliable so it's got all the great features you love about the traditional 87 it's just more rugged beauty so it's actually much easier for me to nitpick about thee well not bad things but just little annoying things about this meter because there's so many damn good things don't get me wrong okay don't fly off the handle cuz I'm gonna point out all the bad stuff it's a top meter I'm just I've already done the 87 so I'm just going to point out the annoying features and they're all just the same on the 87 as well and I think this is the best media can get really so let's check them out one annoying they don't have a push button on/off switch you've got to rotate it to switch it on and well that just adds extra wear to the switch I think aa second annoying thing is that when you go to current it defaults to I see it defaults to AC current and that was annoying on the 87 because that's advertisers as an electronics design meter and really I think you should for electronics you should default to DC but this one maybe because it's more designed for more industrial um use really if you can say such a thing that AC is probably not bad but they're stuck with the default I see I don't like it it's a bit annoying one of the other majorly annoying things is that on the back it doesn't have the default are power on options you know when I reviewed the Fluke 117 they're the flukes lowest cost electricians meter it had all the power on options engraved into the tilting bail but this doesn't have it at all if I take that then if I take the case off on the back here if you've read it where is it ah okay refer to manual for additional capabilities what what are you gonna be kidding me flood fire clue really because if you can do it on your low-cost meetup don't go to the trouble with engraving that on there put the damn things on there look at all this free space you got up here oh really and yes it's got all the same power on options as the Fluke 87 like our high if you hold down Hertz and switch it on it's got the high impedance our DC millivolt mode and that's really handy and it's got you know a whole bunch of other things you can turn off the beep you can turn off the auto power off and all that sort of stuff so you know it's got exactly the same functionality one thing that's always bugged me is to switch into four and a half digit mode you've got to press the backlight button and well that's like your hot press it and hold it down well that's fine but the fact is is that when you do that the back light comes on and that's taking a little pulse of current so you know why if you're pressing and hold it down the backlight shouldn't turn on it's just ah just annoying one thing they have changed from the 87 which I don't like that much is the buzzer listen to it this is the 87 right it's quite low and so it's quite low pitch and it's quite high volume this is the new 28 series - it's higher pitched and well you know it it's different I I think this one's led the old 87 is louder so you know I don't know what they've done there but and they've changed the pitch of it so oh well it's just different I guess and yes the continuity response time is very quick to check it out yeah it catches like the 500 microsecond pulse response same as the 87 beauty and you'll notice yes they have changed the case design - it's different the button once again the 87 has this recessed range switch and the 28 - has has this sort of raised range switch which gives easier access perhaps but it just sticks out more I guess which you're going to have argue is probably not as as well designed as the 80s even perhaps but that's a stretch anyway and as you can see it's the thickness is quite different and it doesn't the 28 doesn't have the rubber surround around the outside and it's just it's just thicker in and it's a curve too it's got the curved sides on it so it's sort of when you're holding the meter without the holster it feels it feels a bit better than the 87 but because the 87 has got the rubber grip it you know but it doesn't matter who the hell holds it without the holster anyway and the holster if you you probably can't see it on here but it's actually slightly thinner I think then the 87 are ways a bit less - I haven't put it on the scale but I think it actually weighs less and it's got the rib things inside there just like the old one and and yes the tilting bail is the same pretty much similar to the old one and it's it's not as plastic and I don't like it but you know yeah what the hell it's just a tool named Bale and the other thing fluke claim with this meter is that you can stick it in backwards like this to actually even store it in the holster backwards so yeah so you protect the rein switching everything else and well I don't think that's all it's cracked up to be because check it out it actually um it actually protrudes from the rubber holster so if you sit it down on the table it actually hits the plastic instead of the holster self and lands flat bang on the plastic I don't like it and you could do the same thing with the 87 anyway now in case you're wondering why they make the 27 series - as well and the differences the only thing lacking in 27 series - over this one they're almost the same price I believe is the temperature a functionality and the fact that it's not true RMS this one's true RMS now the reason why you know some people might like you well why would you not have a true RMS meter these days well the answers are actually really obvious because fluke the old 28 and sorry the old 27 fluke 27 was not a true RMS meet up and they sold Zil yNN's of them to add to the US military and the US military have written thousands and tens of thousands of procedures and manuals based around that meter so based around an average responding meter instead a true RMS so they have to make this one available as a replacement in the non RMS average responding version it just makes sense wouldn't should the average person buy it no the same price by the 28th series - they're the 27 series - is only to satisfy um certain niche markets who want an average responded better well let's check out what you get in the box shall we and the first thing you notice is what's missing and that's the magnetic tool hanger again just like the 87 they sell that separately Fluker being tied Isis again god be $407 some meter give us the damn magnetic hang up please anyway ah you get the alligator / crocodile clips you get the standard fluke test leads and the only other thing you get is the thermocouple temperature probe which is one percent accurate I think and you plug it in and you hit and you put on the DC millivolt mode and that shows the temperature what is it twenty six point nine degrees here in the lab it's you know it's summertime here in Sydney and you know it's a nice little thermocouple probe and well you know it doesn't cost much so they give you that okay let's do the switch on test just to make sure everything's hunky-dory like the 87 and yep no problem at all there's no overshoot there and it works really quite well so no problem and let's just try that again for those who haven't seen it the smoothing mode when you hold down the range button when you turn it on you get the little smoothing icon in the top corner there and if you switch it on it'll go boom and it'll average its way up like that so that's the smoothing mode there is one major change with this meter over the 87 which I really love and that's the fact that it uses double A's double-a batteries instead of the old 9-volt one when I'm winning idea and the battery life it's now 800 hours fantastic that's what you need in a multimeter so that alone might be enough reason to go for the 28 - over the 87 now I wasn't actually 100% correct when I said the functionality is identical between these two units because I did find one difference that's actually worse on the 28 - now on the 87 on the diode test mode it goes greater than 2 volts so let's measure one of these Kree experiment 477 volts okay but I do the same thing with the fluke 28 here it is the lead kind of barely comes on and it doesn't read anything that's because it's maximum mode maximum read range on the diode test range is only 2 volts and this is 2.47 you can't read it so I don't know why they've changed that it's crazy okay let's check out the battery current shower I'm using my microcurrent adapter let's switch it on I'm paranoid from 4 and a half volts and on DC volts is taking 1.7 million switch is well under likely three and a half millions expected for the 800 hour battery life so it's easily going to meet its battery life if you turned on ohms two milliamps five milliamps on diode there you go so let's try the backlight backlight 12 milliamps on low and 30 milliamps on high okay I've let it power off and as you can see it's about drawing about 50 micro amps and if I switch it right off you will find that it drops down to zero I know what you're thinking Dave this is the world's most rugged moly meter drop the bastard alright tada it bounces whoo-hoo check it out and of course it's deal works but there's more to come and I know what else you're thinking this is supposed to be waterproof and it's supposed to float well is it and does it well let's check it out push it right to the bottom and woohoo it floats it's pretty buoyant it's I like it it really is quite a toy it meet up and of course it still works a treat fantastic once again fluke of proving why they're the best multi mean and manufacturer in the business cuz they just don't get it wrong it's a superbly designed so much thought has gone into it I love it it's brilliant so my verdict on the fluke 28 series - well you guessed it a big thumbs up no problems at all I have no hesitation in recommending this meter for for almost anyone really as a general purpose rugged meter it just I don't think it can be beat look ever real winner on their hands here they really do and so who's at fault well as it just as a general bench meter I'd go for the fluke 87 instead because well it's smaller it's a bit lighter and it's a bit more manageable but if you're into any sort of industrial or field use for a few dollars more than the 87 I'd be getting yourself one of these I know what you're thinking that was a pretty lame test I only dropped it from a meter and I only put it in the water for 10 seconds what sort of lame test is that this is supposed to survive a 3 meter drop and it's supposed to survive immersion in water for an up to 1 meter for Oh 30 minutes and well I haven't tested that at all so I will in the next episode where I abused the hell out of this thing ah

Channel: EEVblog

Views: 76,660

Keywords: fluke, multimeter, 28, 27, 87, series, ii, 28ii, review, teardown, pcb, internal, rugged, float, waterproof, water

Id: vkYm021p5qk

Length: 26min 25sec (1585 seconds)

Published: Sat Feb 27 2010