Need help in building resistivity/conductivity sensor circui

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Hi guys,

I’m very excited in building circuit and need advice/help from you guys. I can’t find many circuits on this.

I have done some research on timer circuits (555, c4060, etc) and few tiny Arduino boards and little bit confused.

I want the circuit to work as follows,

First, pair of probes will be connected to this circuit. And the enclosed circuit will be placed inside the alcohol fluid tank with probes injected into the fluid. From there the circuit should check the resistivity for every 4hrs and if found any then the LED should lit up. Also the checking should only done for about 1000-1500ms and not more than this because there might be chance of electrolysis. And a reset button should be there for case where resistivity is found and needs to be cured and start the timer again.

I got two Arduino based boards, one is Nano pro and other is attiny85. Will be great help if you guys can help based on the info provided.

Need more info please ask.

Thank you,

i0s0sx

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What is the fluid and what values do you expect for conductivity measurements?

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jremington:
What is the fluid and what values do you expect for conductivity measurements?

5v minus resistance. Could be anything from no conductivity to very close to 5V or whatever the power supply is.