Patent ID: 6191593
Filing Date: 2001-02-20
Classification: G01B

Abstract:
A method of detecting the presence of physical matter on a sensing surface of a sensor device, comprising the steps of:providing a sensor device having an array of individual sensing cells arranged in a closely spaced physical configuration;providing a dielectric layer covering said array, said dielectric layer providing said sensing surface;providing a coating on said sensing surface that is responsive to physical matter;detecting the presence of said known physical matter on said coating;providing each sensing cell with an amplifier having an input and an output;providing output-to-input feedback for each of said amplifiers, said feedback being sensitive to the presence of said physical matter on said coating;providing said feedback for each of said amplifiers by way of a first capacitor plate that is placed under said sensing surface and that is connected to said input and, a second capacitor plate that is placed under said sensing surface in close spatial relation to said first capacitor plate and that is connected to said output; anddetecting the presence of physical matter on said coating.