Because my original goal is not to measure conductivity, but presence only, I am hesitant to buy an off-the-shelf variant, and I think that it would be awesome to make my instrument.
Right now, precision is more important to me than accuracy. Though, if it seems possible and I can consistently obtain realistic values, that may change.
You’ve given me a lot to chew on, and I will for sure be reaching back out about this. My electrical know-how threshold has been met with Wien Bridges and low power op amps.
The cable I’ve got isn’t shielded, but is essentially power tool cable and is rated within the SOOW category. I think my only concern with it at the moment is how tasty the local fauna will find it when they’re deployed.