Humidity sensor has piezoacoustic resonator element which has two electrode layers and piezoceramic layer arranged between electrode layers, where sensor layer is provided with hygroscopic material for sorption of water

摘要

The humidity sensor (1) has a piezoacoustic resonator element which has two electrode layers (11,12) and a piezoceramic layer (13) arranged between the electrode layers. A sensor layer (14) is provided with hygroscopic material for the sorption of water. The piezoacoustic resonator element and the sensor layer are coupled together such that a resonance frequency of the resonator element depends on a water quantity sorbed by the sensor layer. The hygroscopic material has a ceramic such as alkali niobate and potassium niobate. An independent claim is included for a method for detecting water in a fluid using the humidity sensor.