EC Sensor Design - Newbie

Thread Starter

gapansi

Joined Nov 23, 2020
5
Hello!

I was trying to gather some resources on designing an EC sensor that for instance, I could connect to an Arduino board.

I saw many people on YouTube just using two electrodes and some wires and simply connect them to analog pins of the Arduino board. I do not have much knowledge in electronics but it seems to me that this way of building such a sensor is very unreliable and probably requires that you calibrate the sensor quite often.

I understand the principle behind measuring EC: basically measuring the resistance between the two electrodes.

However, I was wondering if there's a "better" way to design such a sensor. I could not find many sources online myself, perhaps anyone who could help me out here?

A schematic would already help.

Thanks a lot!
 

Sensacell

Joined Jun 19, 2012
2,821
EC means Existential Crisis?

There are so many acronyms floating around, better that you explicitly describe what you are trying to do.
 

Sensacell

Joined Jun 19, 2012
2,821
After skimming the video, i have a better idea now.
The conductivity is dependant on many variables, so calibration is going to be necessary. You need to first determine the range of resistance the device must accomodate before you can design a good circuit to measure it.

I would focus on designing a probe that will minimize the variations due to mechanical changes, pourus materials or unwanted ionic contamination.

Then use an ohm meter to determine the resistance range required, to make best use of the AD conveter reading range.

At the simplest, the circuit could be one resistor to ground to set the range, with the probes connected to input and Vcc.

One issue that may pop up over the long term is corrosion of the electrodes from the small current flowing, this can be mitigated using a more complex AC resistance bridge that eliminates any DC on the electrodes.
 
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