BROAD SPECTRUM CHARGED ELECTRIC FIELD POLAR GAS SENSING AND DETECTION SYSTEM

摘要

An air pollutant and/or fire combustion sensing apparatus includes a capacitive sensor having spaced sensing electrodes producing a free space mounted within an environment subject to possible fire or the like. One of the sensing electrodes has an outer dielectric layer for adsorbing contaminating gaseous products. The electrodes are connected to a high voltage power source for producing a charged capacitor with a high intensity static electric field in the free space or gap. The electric field reacts upon the contaminating gaseous products of combustion and environmental pollution and produces an opposing electric field with a net change in the electric field and the summated voltage appearing across the electrodes. A high input impedance detecting circuit with good electrometer characteristics responds to the change in the field.