Mark Willis wrote:
.........
>What's wrong with a cheap and easy, hot bead thermistor solution,
>though?  Constant current through a thermistor to intentionally
>self-heat it to say body temperature or so, when in free air -  then
>measure the resulting voltage - when water level rises to where the
>thermistor is covered in water, it'll cool the thermistor in a heck of a
>hurry, thus voltage change and you know the water's there.  Want the
>water to not spray onto the thermistor, of course, placing the
>thermistor inside a tube or if needed adding a tank water inlet baffle
>will solve that though <G>  Yeah, it's contact sensing, I know.
>

Plus, I suspect you could use 2 or more thermistors arranged
vertically within the tube, plus a little math, to actually
determine the level, not just whether above/below one point.