alien
Well-Known Member
This document shows you how. The obvious way would be to put the capacitative sensor on or in the sight tube. This is first on a series of articles on methods for liquid level sensing.
http://www.digikey.com/us/en/techzone/sensors/resources/articles/liquid-level-sensing.html
http://www.digikey.com/us/en/techzone/sensors/resources/articles/liquid-level-sensing.html