Reply To: Inexpensive DIY conductivity sensor

Hi neilh

Thanks a lot for your response.

Good idea with the titanium rod. How would you cut that?
Right now, I plan to use PVC to anchor the array to streambeds. I haven’t put the first one together yet, but I intend to use a coupler and end cap that will accommodate a cable gland big enough for my 5-conductor, 18awg cable. The housing for the sensors has been the most challenging part of the build so far. Ultimately I hope to make it as small as possible, but right now, it’s quite hefty.

I intend to validate its precision with gradient testing, where the salt concentration is increased in each sample, the value measured, and recorded.
I want to produce an inexpensive probe that is sensitive enough to consistently detect varying conductance ranges, both in the lab and field.

If I cant make something that is robust and consistent between measurements, Ill probably use one of these:
https://www.adafruit.com/product/3397
It does add some cost to the unit, but its small size and sensitivity make it an attractive avenue for me.

I’ve also thought about throwing a handful of DS18B20s onto a bus together and using the measured delta in temperature to determine water depth.
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