Dew/Frost Point Recognition with Fingerprint Sensor

In dew point hygrometers the condensed water layer thickness and morphology as well can modify detector signal value giving unreliable detections. The classic impedance dew/frost point detector measures mean impedance of whole active detector area, therefore in the case of simultaneous presence of both forms of water (liquid super-cooled water, ice) or in the case of various morphology of water droplets or crystals it is difficult to distinguish those situations from regular operations. The new idea of dew/frost point detector construction based on impedance matrix measurement was described. To test the idea of impedance matrix dew/frost point detector the commercially available fingerprint sensor was successfully applied.