Methods and systems for detecting the presence, or determining the location or the size, or detecting changes of material properties, of an object within a predefined space

Abstract

A method for detecting the presence, and/or determining the location, and/or detecting changes in the material properties, of a first object () within a predefined space () and compensating for the disturbance caused by a second object, where the method comprises the following steps: providing at least a first and a second electrode () capacitively coupled to each other; conductively applying an electrical signal to each of the first and second electrodes (), the electrical signals being different for the first and second electrodes (); for each of the electrodes () measuring the current signal through, and/or the voltage signal on, the electrode (); deriving from the measured values an indication of the disturbance caused by the second object; and deriving from the measured values and the indication of the disturbance a disturbance-compensated indication of the presence, and/or the location, and/or changes in the material properties, of the first object ().