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What are - for you - the 3 biggest disadvantages of your benchtop DMM(s)?

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AVGresponding:

--- Quote from: bd139 on September 01, 2020, 01:33:53 pm ---3478A:

1. Horridly bad LCD display
2. No continuity / feeper
3. Terrible front panel legend meaning I always stick my probes in the wrong holes.

That’s about it.

--- End quote ---

Ooer missus!   :-DD



For me, it's size (just can't get away from those double entendres),   ::)

The ones that aren't exactly full or half rack width,   :wtf:

The LCD display ones with no/poor backlighting.   :palm:

joeqsmith:

--- Quote from: wizard69 on September 02, 2020, 02:13:39 pm ---It is pretty easy to come up with 3:

* No Cat rating or CAT ratings that don't reflect needs on a repair bench.   The reality is that even rather small servo drives run at 500 VDC sometimes 650 VDC bus voltages.   There is enough happening on repair benches that having the higher safety ratings would be of real value.
--- End quote ---

I would imagine most bench repair work is CATI/II.   If the safety standards are only there to keep the operator safe and not prevent damage to the meter, then the CAT ratings would seem to have little value.  If the intent of the safety standard is only to keep the operator safe, which is what many here suggest (I don't know personally)  there is little need for MOVs, GDTs, PTCs, surge rated resistors, high speed clamps and such. 

Even some of the larger supplies I have worked on don't have enough storage to pose much of a risk if a meter were to breakdown.  I'm not suggesting there are no safety risks, but that the meter would have little to do with it.  If we understand the risks and how to mitigate them (remove rings, one hand rule...) then to me what becomes a real value is meters that are robust enough to survive some low energy transients that you may see on the bench (repair, experimenting....).    This is where the EMC standards come in to play and there should be little doubt the need for added protection circuits to allow the meter to survive.   

How do you quantify how robust a meter is?  Who knows.  I've presented my test methods and the data I have collected.  I would say the actual data carries less weight than opinions.   If your goal is to sell meters and the products you sell perform well against my tests, you may praise the results.   If they do poorly, you may talk about how the tests don't represent real world conditions.   It becomes more about the culture we have today where everyone's an expert after a quick browse of wiki.   

I'm currently reading a pretty good book on this topic titled "The Death of Expertise: The Campaign against Established Knowledge and Why it Matters"
https://www.amazon.com/Death-Expertise-Campaign-Established-Knowledge/dp/0190469412

Sorry for the long post.  If you were trying to make a different point with your comment, if you would'nt mind explaining further, I would like to understand it.

****
first post of the day.  cleaned up some of the wording.

Fungus:

--- Quote from: wizard69 on September 02, 2020, 02:13:39 pm ---It is pretty easy to come up with 3:

* No Cat rating or CAT ratings that don't reflect needs on a repair bench.   The reality is that even rather small servo drives run at 500 VDC sometimes 650 VDC bus voltages.   There is enough happening on repair benches that having the higher safety ratings would be of real value.
--- End quote ---

CAT ratings have very little to do with voltage, they're to do with energy. I doubt your repair bench can supply enough energy to create/sustain a decent arc flash.

(and you should probably be upgrading your fuse box if it can)

bdunham7:

--- Quote from: joeqsmith on September 02, 2020, 03:24:55 pm ---
I would imagine most bench repair work is CATI/II.   If the safety standards are only there to keep the operator safe and not prevent damage to the meter, then the CAT ratings would seem to have little value.  If the intent of the safety standard is only to keep the operator safe, which is what many here suggest (I don't know personally)  there is little need for MOVs, GDTs, PTCs, surge rated resistors, high speed clamps and such. 

--- End quote ---

I'd speculate that some people may have lost sight of exactly what those CAT ratings are actually intended to protect us from.  I work on some fairly high voltage and moderately high energy systems, on the bench, but the typical bench meter that is rated CAT 1/1000V and CAT II/300V (or more in some cases) is more than adequate, IMO.  Unless  you have a service panel in the middle of your bench, those are the actual levels of exposure you have.
   

--- Quote ---How you quantify how robust a meter is, who knows.

--- End quote ---

I just took apart an old 8842A that apparently was connected to excessive voltage--at least 1500V---with some power to back it up.  The entire front end protection--4 MOVs and 2 fusible resistors--were incinerated.  I removed the burnt parts and subbed in 2 regular 1K resistors (to be repaired properly later, of course) and the meter works properly and is in cal.  No evidence of any external damage, the circuit board is unharmed (but sooty)  and I'm sure nobody died.  I'd say that is 'robust' although I can't quantify that. 

ferdieCX:
My dream would be a Fluke 8050 with LED Display and:

1) Service documentation
2) No unobtanium parts
3) 4-wire resistance measurement would be a plus.

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