Happily there is a solution in the form of capacitive sensor probes, and it is these that [Electrobob] is incorporating in to a home automation system. Unfortunately the commercial capacitive ...

Their capacitance — and therefore their charging rate — changes in response to how much water is around them. By measuring this effect on a probe sunk into dirt, the sensor can therefore ...

Detection and control of the level of liquid in a reservoir is another suitable application, as Cx increases because rising liquid level increases capacitance between the liquid and an insulated probe ...