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Basic Electronics » How do I read very low voltages with the Nerdkit please? (0 to 20.0 mV)

June 12, 2010
by Wobbler
Wobbler's Avatar

I'm looking at the temp sensor project and wondering what I would need to do to read from a sensor which outputs a range 0 to 20.0 mV?

Can anyone suggest anything please?

Thank you!

June 12, 2010
by mrobbins
(NerdKits Staff)

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Hi Wobbler,

My recommendation would be to amplify those voltages before reading them with an analog-to-digital converter. Our digital strain gauge tutorial showed us using an AD620 instrumentation amplifier to read a tiny (maybe 5 or 10mV full-scale) voltage.

With a small signal like that, you also need to be aware of "input offset error" in any amplifiers or other components in your signal chain. (FET-based op-amps tend to have higher input offset error, sometimes in the tens of millivolts.)

Does that help get you pointed in the right direction?

Mike

June 12, 2010
by Wobbler
Wobbler's Avatar

It does! Thank you. :o)

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