I’m actually looking at building an EC meter which calculates the electrical conductivity of water (as the subject says so …).
This will then be doing some basic actions for correcting the solution (water) with some salts.
By the way, i’ve got a lot of problems gathering the informations on how these probes works.
I’ve got a pH probe too that will be interfaced thru a Phidgets 1130 module (this works pretty well by the way !).
I found this probe, cheap product compare to others : http://www.top-messtechnik.com/jtlshop/index.php?a=676&lang=eng
As my questions remains, i asked the owners of the site to help me a little on their probe. I hope they will answer with precious informations.