Specific material detection and measuring device

Abstract

A device for sensing the presence of and measuring the concentration of a specific non-aqueous particle or gas material in an environment, the device comprising an interdigitated capacitor having at least a pair of selected covering layers thereupon, said pair of layers comprising a first passive electrically insulative layer and a second material layer having a spacial relationship to said first layer, said second layer selectively permeable to the specific material to be sensed and measured; said second coating, when juxtaposed said first coating, selectively permitting permeability of the particular material sought to be sensed and measured, and when spaced apart, permitting passage through of the specific material in order that the material may migrate to the proximity of the first coating and thereby be sensed and measured. The presence of the specific material modifies the dielectric constant of the dielectric in the interdigitated capacitor electric field and thus the capacitor's capacitance, whereupon the interdigitated capacitor's capacitance is compared with a proximate temperature sensing interdigitated capacitor in a capacitance sensing circuit and by the change of the capacitance, the presence and concentration of the specific material determined.