Fluke 101 selloff?

[joeqsmith]

Thanks for taking the time to post those.   It appears to be the same as what I have.   

While I have seen many of the 5mm PTC's come apart during my testing, I have yet to see one of these larger parts break down.   The 121GW for example uses a couple of PTCs in series for a load.  Even with my small generator, we saw that section of the switch breakdown. If the PTCs breakdown, there's not much that will limit the current.   

I've had the smaller resistors fail as well during my testing but not these larger parts. 

I like how things are spread out.  All in all, it looks good and makes sense that it has held up so well with my testing.   There's really no excuse that a meter designed today wouldn't consider the basics and handle some basic transients like the 101.   

[rsjsouza]

Thanks for sharing the photos! It really looks a quite well built meter.

Is it just me or the PCB looks like a smiley face?

(Same thing can be said about the back of the front panel).


P.S. Sorry about the psychedelic image; I am on my cell phone and the only drawing SW I have is my kids' doodle app.

[Fungus]

I like how things are spread out.  All in all, it looks good and makes sense that it has held up so well with my testing.   

Looking at this pic, you can see exactly why it stands up to your transients. Big chunky components, good spacing, PCB slots and separator walls.

There's really no excuse that a meter designed today wouldn't consider the basics and handle some basic transients like the 101.

Yep. There's no secrets there, it's just input protection done by the book. There's no reason anything but the cheapest of meters shouldn't be made that way.

[floobydust]

The 61010 spacings needed are absolutely huge which is difficult to meet in something small and handheld.
The 1k surge resistor also needs to be huge, reinforced (double) spacing between its terminals and 2X power rating during DMM misuse.

Fluke had the patent for their multimeter protection scheme, it expired today. Might explain why Keysight is using sluggish GDT's.

[BravoV]

The 101 with minimal features and without current measurement alone, has huge advantages in the design as to spare no expense in practicing good & proper input protection mechanism, as we can see there are still plenty of spare unused space, cmiiw.

[joeqsmith]

The 101 with minimal features and without current measurement alone, has huge advantages in the design as to spare no expense in practicing good & proper input protection mechanism, as we can see there are still plenty of spare unused space, cmiiw.

While the Brymen BM869s is very robust when compared with other meters I have looked at,  I've had one of mine all the way up to 14KV without breaking down or damaging the meter with nothing more than a transistor swap.   That's a packed meter.   That low end HIOKI would have made it up this high had they added just extended the plastic a bit further.    There's certainly a few companies that know how to design very robust meters regardless of the cost and size.

[Fungus]

The 61010 spacings needed are absolutely huge which is difficult to meet in something small and handheld.

Distances can be 3D and/or airgapped, see photo four posts up where you see the slots in the F101 board and raised dividing walls to separate components.