Meter screw up a fluke?

[Tha fios agaibh]

I always trusted my fluke meters but i noticed my 87iii screwing up reading lower resistances.

I comparitively checked a resistance of 467Ω and got 467Ω on my fluke 115 and fluke 87v but my fluke 87iii said O.L.

I checked it again and it was right but read .467k

Suspecting the autoranging feature wasn't working correctly, I manually toggled through the ranges and all read good except it read O.L in the Ω range.

I was wondering if there are known problems with the 87iii model. I know all other features work fine and I always verify 0Ω by touching leads together before taking a measurement to eliminate a lead problem.

 

[Bluejets]

Some only go to 200 on low ohm.

 

[Tha fios agaibh]

I can dial back a 5k pot and autorange feature switches ohm scale below .4k into 400Ω and below.

Sometimes it reads ohms, Sometimes it doesn't.
I should be able to read ohms in the ohm range regardless.

I've had this meter about 25 years and it was always reliable until now.

When I get a chance,, I'll cack the case open to see if battery acid might have messed up something.

 

[Tha fios agaibh]

I think I found it, it's seems to be working correctly after I reassembled it.

 

[davenn]

I think I found it, it's seems to be working correctly after I reassembled it.
View attachment 52345

Those are trimmer capacitors, NOT trimpots.
If you have played with them, you may find frequency or capacitance readings are now screwball

 

[Tha fios agaibh]

Those are trimmer capacitors, NOT trimpots.
If you have played with them, you may find frequency or capacitance readings are now screwball

You missed it Dave, the upper cathode leads of those diodes were touching.
I don't know how it happened because they were under a protective cover. Perhaps it got dropped?

Anyway, I separated them and all seems well.

 

[davenn]

You missed it Dave, the upper cathode leads of those diodes were touching.

ahh, you didnt comment about that ... you were commenting about trimpot(s)

 

[Tha fios agaibh]

Ah, No I was using a 5k pot as a reference to check resistance range on meter.

I didn't elaborate in part, to see if someone would comment on the yellow component in the back that looks cracked. (...It's not)

 

[73's de Edd]

I didn't elaborate in part, to see if someone would comment on the yellow component in the back that looks cracked. (...It's not)
Spark gap cap . . . . avec . . . .PRECISIONLY sawed in gap.