[pinkfloyd4ever]

ok so I have an old low-end Fluke 18 I got on ebay that was made in '96 and I have 2 cheapos that I've bought in the last couple months, one Centech and one Tenma (mcm house brand) that has pretty much the same features and seems to be of similar quality to the Centech. The Centech and Tenma give voltage readings pretty close to each other, but both read significantly higher than the Fluke. I've always gone by the readings the Fluke gives me, but I recently saw someone on here compare the readings of a Centech and some nice bench meter, and they found that they were pretty darn close, so I've been having second thoughts. So which would you trust more?

 

[amphead]

A new or nearly new Fluke would provide the most accurate reading. No telling what the Fluke you purchased from E-bay has been through. One way to find out is to go to your local electronics dealer and find/tryout a new model, with your old model A/B at the store.

 

[kipman725]

build an ultra stable voltage referance using one of the voltage referance IC's and calibrate the meters to it. Then Build another voltage referance at a different voltage and see how close the meters are to that. Repeat every few weeks.

 

[error401]

Yea, just tack an LM4040 or two (available in 2.5, 5, 10V) onto your next order. $2.50 for a 0.1% voltage reference ain't bad. Should let you know if any of them are grossly out.

I'd be inclined to trust the two that agree. How much difference are we talking?

 

[tangent]

If you get the Fluke calibrated, then I'd trust it more than the others. Calibration isn't even an option for the cheapies.

 

[Blind Tree Frog]

What's that saying about an engineer who had one ruler and was happy because he knew how long everything was, and then he got a second ruler and was sad because he no longer was sure?

I'd probably err on the side of the two that agreed with a bias towards the third (if the two agreed at 9 volts, and the third was 8, I might assume just unger 9 volts type of thing). I don't have a PE though.

 

[pinkfloyd4ever]

Quote:

Originally Posted by tangent /img/forum/go_quote.gif If you get the Fluke calibrated, then I'd trust it more than the others. Calibration isn't even an option for the cheapies.

about how much would that cost?