Just got my "new" multimeter ... the family become larger ..

[NiHaoMike]

Those are some old batteries. 2200mAh C cells. Now 2200mAh and above AA cells are sold in supermarkets, even. (I assume those are for memory backup or an internal clock?)

A few oddball components (current shunts and precision resistors) look very similar to what's in my 8021B. (And despite it being about as old as Britney Spears, it is still very accurate and the frequency response is at least as good as my Mastech MS8226T.)

I think the Flukes using that chipset use a non-multiplexed LCD. It should be easy to build a converter board to allow the original display to be replaced with some LED displays. Red or green for the retro look, or blue for the futuristic look. (Use window tint or something on the display cover to improve contrast.)

[Kiriakos-GR]

The meter is an  2000 counts ..

So it goes at 1.900 V
Or  19.99 V
Or  199.9 V
Or  1000 V

So its three dashes .

By my understanding , The IC and the display , its an common volt meter .

But some how it knows where to set the dash .... in comparison with ready cheap LED panel volt meters,
that you have to set the scale manually with resistors .

My only fear are, that any additional circuitry it will possibly compromise the accuracy of the instrument.

I have to admit , that building converter IC's its not my strong point.    

[david77]

Well, if you replace the display with a off-the-shelf display you wouldn't need any special circuitry. You also wouldn't affect the accuracy of the meter as that is depending on the big Intersil IC.

Unless you get the original part that is probably the easiest solution. Just have to figure out wich pin goes on wich segment, shouldn't be to hard.

David

[Kiriakos-GR]

I will wait for the next 5 days , the responses , of the sellers and companies , that I had ask for help .
At the same time I will start to collect info about the alternative solution.

I all ready have three LED displays (digits)  next to me ..  I am missing the one with the minus sign and the digit.

The manual of the  8012A , has the full schematic in it , I will study it too .

[Kiriakos-GR]

Those are some old batteries. 2200mAh C cells. Now 2200mAh and above AA cells are sold in supermarkets, even. (I assume those are for memory backup or an internal clock?)

Nop,  those are secondary power source , the meter operates with them for few hours .
If I remember correct  .. about 16 hours .   

[Kiriakos-GR]

God loves me !!!        

And the forces of the universe are with me ..    


Yes another one ..  on the way to Greece ..  Spare parts for ever .  

[MrPlacid]

Wow, great deal you got there.

Do you know if Fluke still make bench top multimeter?

[ThunderSqueak]

why u interested in this bench type multimeter? the handheld DMM is not enuf?

Maybe there are times when size does count?   

[Kiriakos-GR]

the handheld DMM is not enuf?

Well, my wish are to make both active ,  for the second one , I will find one solution in time.

And the best part about bench top meters, are that you can have them at any positioning you like.
They have their own spot on the bench , they do not get scratched or damaged by surrounding objects.
And you do not care about batteries ..    

And if they have dual powering option like AC + Rechargeable batteries  , thats even better.  

[alm]

Do you know if Fluke still make bench top multimeter?

Sure.

[MrPlacid]

Thanks, Alm.

Wow, look at the number of digits on this guy...

[KTP]

Thanks, Alm.

Wow, look at the number of digits on this guy...

How in the world could a meter be accurate to that many digits???

Do the probes come with some sort of thermal monitoring system such that the copper resistance can be known if the room temperature changes by 0.1 degree?

[Kiriakos-GR]

i think the price will be the same digit number... USD1000604? maybe

Thats True , but even those oldies , at top shape ( verified ) , they sold for 150 USD !!

So it is an worthy solution , for using them for simple every day tasks .

About the Fluke oldies , there is an model called  8050A   4+1/2 digit .

But from the statistics on the ebay , this one looks to get easily damaged , in comparison with the 8010A & 8012A  brother models.
Many dead  8050A are available ..  
But I preferred the most " hard to die " series .  
With out to care about the one digit less.

[Kiriakos-GR]

By the way , does any one knows , how you can totally remove the black handle-stand ?

It pulls out up to a point , so to rotate it freely , but I do not see how I can remove it completely ,
so to clean the exterior case,  easier.

[Zad]

Thanks, Alm.

Wow, look at the number of digits on this guy...

How in the world could a meter be accurate to that many digits???

Do the probes come with some sort of thermal monitoring system such that the copper resistance can be known if the room temperature changes by 0.1 degree?

Voltage sensing to 6+ digits (20 bits) isn't a huge problem. Not sure about current though, even with a transimpedance amplifier. You could certainly get enough resolution to obtain good differential linearity, which is what matters. Precision resistance measurement is done with 4-wire (Kelvin) sensing, which effectively calibrates out the effect of the wires.

Looking at the specs, current accuracy is around 5 digits. 4-wire resistance accuracy around 6 digits. Niiiice.

[alm]

That's just a 6.5 digit meter, these have been available for like thirty years (eg. HP 3455A/3456A). Their 8508A is closer to the top end. Voltage measurement isn't that a big deal, although thermal EMF (Seebeck effect) can be an issue (that's why they make those low-thermal EMF leads). For resistance measurements, you can use four-wire Kelvin connections to eliminate contact resistance.

[slburris]

I've got a Fluke 8505a (top) and Fluke 8502A (bottom) bench multimeter.
Both are 6.5 digits, and they aren't very expensive on Ebay if you persist.
Mine seem to be in excellent calibration (at least they agree with
each other).  This is a good thing because their specs far exceed anything
I have to calibrate them.

They are big and heavy compared to current bench meters, but they were
a bargain.

Scott

[Mechatrommer]

By the way , does any one knows , how you can totally remove the black handle-stand ?
It pulls out up to a point , so to rotate it freely , but I do not see how I can remove it completely ,
so to clean the exterior case,  easier.

try to see if any plastic covering on the handle, usually on the rotation point, see if can poke it out, maybe a screw lying underneath.
or there maybe a specific angle to unlock it, or maybe you can see from inside how the thing got connected to the body/casing... to get an idea.

[alm]

Current measurement is usually just a shunt ammeter, so in theory it isn't any harder than voltage measurement. The only issue is the stability of the shunt resistor, especially at high(ish) currents.

You can often get old bench/system DMM's from that vintage fairly cheaply. Apart from the size, the main disadvantage is the bare-bones feature set. Often just DC voltage is standard, and ohms/ACV/current are options (or not available at all). Pay attention to those options if you buy it. But it's hard to beat them for stability/accuracy/precision without spending $1k+. They can also have neat features like lots of readings per second, storage and math.

You can often tilt the handle to a certain position and pull it completely out. Should be in the service manual.

[Excavatoree]

God loves me !!!        

And the forces of the universe are with me ..    


Yes another one ..  on the way to Greece ..  Spare parts for ever .  

I warned you.   

[Kiriakos-GR]

By the way , does any one knows , how you can totally remove the black handle-stand ?
It pulls out up to a point , so to rotate it freely , but I do not see how I can remove it completely ,
so to clean the exterior case,  easier.

try to see if any plastic covering on the handle, usually on the rotation point, see if can poke it out, maybe a screw lying underneath.
or there maybe a specific angle to unlock it, or maybe you can see from inside how the thing got connected to the body/casing... to get an idea.

Thanks  shafri , I moved one step further , taking the risk , to remove the aluminum label with a blade.

And ... ended victorious ..    

Undocumented  finding , for all the old Fluke bench top meters !!  
8010A  
8012A
8050A

[MrPlacid]

Kiriakos-GR , I like the photos. I love taking stuff apart but hate it when I don't know how. Sometimes I end up ruining a unit because of it.

[Kiriakos-GR]

I did not took pictures of the next step ...
called as  " removing any contamination "  (main cabinet) and  "removing scratches "  from the stand it self ..

I had wash out everything , three times ( hard brash - soft sponge )  ..   

And now its drying , for first inspection.

I always do that, if an item that I buy on ebay , was at an unknown environment . 
I am a smoker , so I care less about contamination from nicotine ,
but I worry most for all the rest factors.

At industrial environment , even the lubrication oil that is used for some tasks ,
its totally toxic ..   oil spots  travels  from hands to the exterior of some devices ,
the devices  travel for repairs ,  and the oil travels from the device at the hands of the technician,
and he transfers the contamination , at everything he touches =  tools like multimeters .. 

The Tip of preferring to  get on Ebay , shinny clean  and in good condition instruments,
its a sign of less or none contamination , from industrial chemicals .


My baby drys out 


 

[Mechatrommer]

Kiriakos-GR , I like the photos. I love taking stuff apart but hate it when I don't know how. Sometimes I end up ruining a unit because of it.

thats how we/i usually learn. but just as Kiriakos said... u'll move one step further... by destroying it

[Kiriakos-GR]

I have one link to share   about LED display on the 8050A    

http://www.xs4all.nl/~lous/fluke/Fluke8050Asite.html

And I must had lost my mind , because I am now talking with some one ,
so to get also and one  8050A .   4 1/2   digits    

Only the 8050A -01 ( with battery option ) can be easily converted to operate 110v or 220V .
So I am waiting to find out this detail.


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