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Testing a Multimeter

Hello all,

I am looking at buying a used Fluke multimeter (either an 8060A or a

77-III) from a local guy and I'm looking for simple tests I can do on each meter. Neither meter has a current calibration so I certainly don't expect the either to be perfect. I may send it off for a proper calibration after buying it, but at this point I'd just like to test that the meters are fully functional. I have a regulated dc supply, a new carbon-zinc battery and some 0.02% resistors (1,100,10K) that I could bring for basic circuit tests. If the dc voltage, dc current and resistance all checkout ok, can I assume the AC functions are ok? Beyond obvious signs of damage, Is there anything in particular I should look out for?

Thanks, Jamie

Reply to
jamiesmyth_uni
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Reply to
John Fields

Hello all,

I am looking at buying a used Fluke multimeter (either an 8060A or a

77-III) from a local guy and I'm looking for simple tests I can do on each meter. Neither meter has a current calibration so I certainly don't expect the either to be perfect. I may send it off for a proper calibration after buying it, but at this point I'd just like to test that the meters are fully functional. I have a regulated dc supply, a new carbon-zinc battery and some 0.02% resistors (1,100,10K) that I could bring for basic circuit tests. If the dc voltage, dc current and resistance all checkout ok, can I assume the AC functions are ok? Beyond obvious signs of damage, Is there anything in particular I should look out for?

Thanks, Jamie

Reply to
jamiesmyth_uni

jamiesmyth snipped-for-privacy@yahoo.ca wrote: Is there anything in particular I

4 connectors while checking for< 1 ohm reading.

Will explain many weird readings !

Yukio YANO

Reply to
Yukio YANO

Just check that all ohms and volts ranges appear to work OK. That may be more than enough.

Reply to
Homer J Simpson

In addition to the other advice (check AC, too -- use a transformer on one of the lower ranges, and also test line voltage), have the seller open the case (one screw on the 77-III, 4 on the 8060 AFAIR) and look at the circuit board. See if there's any damage or blown traces(not a killer in itself -- some of mine have been offered for Baptism of Fire and been repaired by me without problem) and make sure it looks to have been repaired competently. I believe there's a 1K fusible link on the

77-III (there is one on the 77 and 77-II). It blows when you try to measure the resistance of the AC line. Make sure that hasn't been replaced with a 1K 2 watt resistor. That's a nasty thing to do -- replace the safety component with a commonly available non-safety one, then sell it before she blows), but it's been done. Without a fusible resistor, the IC and your meter will be dead for sure on the next fault.

If there is visual evidence of a repair, have the seller take out the assembly and look on the underside of the circuit board -- check for workmanship there, too. Caveat Emptor, and all that. Retest after putting it back together.

If the seller won't cooperate, chances are there's something to hide.

Good luck Chris

Reply to
Chris

If both meters are functional you can cross calibrate to see if one of them is damaged. As long as the readings are withing the meter's specification you should be o.k. You can use your power supply and resistor assortment to check out the resistance, D.C. voltage and current ranges.

You can do a crude check of the A.C. by checking the mains. If your bold enough (balls enough) you can use your resistors to exercise the A.C. ranges on the meter. CAUTION: IF YOU DON'T KNOW WHAT YOUR DOING, I WOULD WARN AGAINST DOING THIS. IT COULD BE FATAL.

Chris wrote:

Reply to
Mr. Wizard 

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JF
Reply to
John Fields

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