Patent ID: 8521431

Claim:
A system for indicating presence of ice water, said system comprising: at least a first temperature controlled self heated sensor responsive to liquid water and ice water and a second temperature controlled self heated sensor responsive to liquid water, a first variable power source for the first sensor, the first variable power source having an output power responsive to changes in the liquid water and the ice water contacting the first sensor; a second variable power source for the second sensor, the second variable power source having an output power responsive to changes in the liquid water contacting the second sensor; and a processor for: determining a first measure indicative of the ice water and the liquid water contacting the first sensor using a sensed output power from the first power source and using evaporation characteristics of ice water and liquid water; determining a second measure indicative of liquid water contacting the second sensor using a sensed output power from the second power source and using evaporation characteristics of liquid water; and subtracting the second measure from the first measure to indicate a presence of the ice water.