A look inside / mini review: Fluke 28 II EX (Pre-production model)

[@aptsys]

Ah. Finally a multimeter that's safe to use in the W.C.

[@antraciet]

Indeed. They exists for a long time, but the last few years they are getting more popular, for the DIY also.

[@mjlorton]

Yes, correct...thanks for the input.

[@willywgb]

Martin The screws that fasten the back cover on this Meter are called Torx (pronounced torks) Willy

[@AintBigAintClever]

Nice teardown. Not many people will get their hands on one of these, let alone whip the cover off!

[@mjlorton]

Thanks for the input.

[@deathventure]

The front daughter board is for further input protection, they are an array of DF series full wave bridge rectifiers. If I saw right, on the back daughter board, there were two small relays, so I believe those are also contributing to input protection. Something to do is to look up the actual part numbers to get more insight on what they do.

[@Monkeh616]

Yes, that's an SMT inductor. Dave Jones had to replace the same part several times on his 28II after drop testing.

[@peterxhudo5177]

are you sure the production 28ii ex came with a bar graph? I just purchased one and it doesnt have a bar graph and fluke was no help the production date is 09/11

[@bouipozz]

Also looking for info on this

[@filipsz6728]

I just made some small research and looks like the one without bargraph has bigger digits.

[@Die-Spezialisten]

I got 2 new ones. Both without bargraph. The newest one is from 2021

[@matlesterdivinagracia6528]

I think that green one that connecting the big redistor that you called MOV is a PTC

[@mjlorton]

Thanks...correction made with an annotation.

[@mjlorton]

All account are generally approved within 24 hours. What probably happened is that you did not receive the confirmation email. Try login, if there's a problem email me. Cheers, Martin.

[@SteveRobReviews]

Fantastic, well done Martin,thanks !!

[@deathventure]

A likely event is that high voltage creates arcing over that particular fuse more so than the second fuse so they pot it to avoid the possible arcing to other components. Given that it's a prototype, they've probably done something different with the release to market version.

[@chrispychickin]

I'll bet Dave watched this and thought, "damn, why didn't I get one of these!"

[@mjlorton]

Torx / torks...thanks, Willy!

[@bambam144]

great video thx a lot martin and a big thumbs up for this beautiful mulitmeter

[@mjlorton]

bambam144 My pleasure.

[@DanFrederiksen]

The Ex doesn't stand for explosive, it stands for expensive :) 1150$ retail. I think you could have used the expression 'for the price' a couple of times here : )

[@ComplexPole]

The 4-pin SMD devices on the top daughter board look to be bridge rectifiers.

[@movax20h]

These are probably clamping diodes.

[@Monkeh616]

XAF1 and XAF2 are the 2mm banana sockets for the 440mA fuse.

[@nuntana2]

Great, thanks. Fantastic bit of kit.

[@SolidStateWorkshop]

MOVs are usually shiny. PTCs are usually a matte finish

[@NaveedAhmad-cd8op]

I have Fluke 28 ii ex multimeter after replacing the MOV's now it's showing 600-ohm resistance instead of unlimited resistance. Please share your experiences?

[@designdemos8021]

The 'gunk' you refer to that encapsulates the 440ma fuse and used on the board is a potting gel - Arnocanali Isol Gel. This fuse assembly (part no. 4016494) is hard to get hold of and relatively expensive at 40EUR compared to the regular Bussmann DMM440/100 (440mA, 1000V, 10.3 (Dia.) x 35mm) fuse it contains. You can quite easily dig the fuse out of the gel compound and reinstall with the potting compound, cost 12GBP via fleabay plus the cost of the fuse, a round 5GBP. The trick to re-potting is to correctly align the pins while setting in the gel. I created a 3D print to locate the pins precisely. Contact me and I'll make them available.

[@mjlorton]

Remember this is based on the original Fluke 28 II so that board might be from then.

[@mjlorton]

If you watch T4D #31 I explain why it's gone...hope to have something back soon.

[@mjlorton]

Yes...didn't think of that! ;-)

[@filipsz6728]

Can someone tell me where I can buy holster for this meter?

[@drpsht]

you mixed up the MOVs and PTC again, Martin. :) That next to the power resistor is the PTC, the other 3 are MOVs. BTW, I'm waiting for a forum account approval for a month now, what's going on?!

[@matlesterdivinagracia6528]

yeah men that green one that he call MOV is a PTC 100% sure

[@bkupiec]

I wonder why only one fuse (440mA) was potted?

[@spagamoto]

28:00 Copyright 2008? This thing was made in 2012... perhaps they didn't update the board text?

[@NicuIrimia]

c'mon Martin, can't you just see the LED (D56) at 27:36 ? it sit's in the middle and top and bottom "bits" are receivers :)

[@Die-Spezialisten]

IMPORTANT!!!!! Watch out for the batteries. If you use normal Alkali batteries, check them regularly or change them. When they leak, the gases can not get out and the dirt gets on the PCB. The gases can destroy the pcb. Also the housing plastic will be destroyed. My 28-2ex is dead because of that. The new one has got Lithium AAA batteries.

[@chrispychickin]

Look closely at the screen as martin pulls off the screen protector, digits get illuminated by static charge. Kind of ironic considering the overall design of the meter ;)

[@DLTX1007]

Be careful about the high res range, it's x10 the counts accuracy range

[@rolandtutorial3377]

Ilike that 😊

[@movax20h]

How it can be intrinsically safe when it has high current amps measurements. In theory you could have leads accidentally in current sockets, and then connect to measure mains voltage for example, and create a spark on leads contact. I do not like it.

[@Die-Spezialisten]

The housing is completely water and dustproof. Also the fuses. So a spark can´t get out. The manual says: in ex zones you may measure with max. 5A and 65V

[@mikeadler434]

👍👍

[@walterramjet]

not 1000 amps @ 1000 volts LOL, 1000 amps "or" 1000 volts.

[@blakebuchanan1420]

a lot of use of "obviously" when reviewing something not obvious

[@thomasleerriem6872]

I'd never put duracell batteries in my gear. They're notorious for leakages. Apart from their overrated price, they'll cost you even more by damaging your stuff.

[@bouipozz]

I just ordered one of these meters... and a pack of Procell batteries to go with it haha. Do you have a preferred brand?

[@Die-Spezialisten]

I experienced it. My meter is dead. The gases get into the electronic section and destroy it.

[@keramzytowymocarz7104]

what a dush strip sticker