Go Down

Topic: Making an Arduino multimeter (Read 1 time) previous topic - next topic

s_premkumar999

Hi All,

I want to make a multimeter with good precision in measuring resistance mainly, Actually it is not used as a multimeter, I want to measure the resistance of some components in both polarities, It must be capable of reading from 0 ohms to 60 M ohm. And also the main design thing is to inject very less current to the device we are testing since they are very sensitive device. Any Ideas to make it with an Arduino and a display. ??

Thanks

arduinoadrian

Quote
with good precision in measuring resistance mainly


-What resolution you want? 1 Ohm, 10 Ohm, 100Ohm, 1K Ohm....
-Up to how much error can you accept in the measurement and consider it reliable for your needs? +/-1 Ohm, +/-10 Ohm, +/-100Ohm, +/-1K Ohm.... That is, what accuracy do you need?
-Is 0-60M the actual range the resistance can take? Can it be reduced somehow?
Perseverance is 90% of the solution. The remaining 10% is more perseverance.

Peter_n

This is such a meter: http://www.hioki.com/products/lcr_resistance_signal/lcr_resistance_meters/684
Those cost between 500 and 4000 dollars.
Hello, I don't get notified of new posts after the forum update. When you need my help, try sending me a PM; yell very loud; knock on my door; whatever is needed.

s_premkumar999

An error of +/- 10 ohms is acceptable. and also the range can be reduced to 0-40M

Chagrin


avr_fred

40 Megohms and the OP wants to resolve to within 10 ohms? That's +/- 0.000025% or 0.25 ppm.

The best you can do with the 10 bit ADC of the Arduino with a 40Meg input would be to resolve to 40k ohms. That's an error 4000 times greater than the OP's looking for and that's assuming no error in the measurement!

You need to research a Wheatstone bridge and 4 wire measurement systems to have even half a chance of doing anything useful. http://en.wikipedia.org/wiki/Wheatstone_bridge Then you're going to need a good, chopper stabilized micro- or nano- voltmeter.

BTW, the accuracy of the commerical meter the one poster provided a link? They don't even list it! One the 1k ohm range it is +/-0.006%

Go Up