Combustion products detector

Claim 1

A DETECTOR UNIT FOR DETECTING THE PRESENCE OF PARTICLES IN THE AIR COMPRISING, A SINGLE IONIZATION CHAMBER ADAPTED TO RECEIVE THE AIR WITH SAID PARTICLES THEREIN, A PLATE EXPOSED TO SAID CHAMBER, MEANS GROUNDING THE CHAMBER TO ESTABLISH A POTENTIAL ON SAID PLATE IN RESPONSE TO IONIZATION OF THE AIR IN SAID CHAMBER, AN ELECTROMETER TUBE HAVING A CATHODE, AN ANODE AND A GRID, MEANS CONNECTING SAID GRID ONLY TO THE PLATE IN A FLOATING GRID CIRCUIT, AN ALPHA EMITTER DEPOSITED ON SAID PLATE IN THE CHAMBER FOR IONIZING THE AIR THEREIN, MEANS FOR ESTABLISHING A CONTROLLED ELECTRON FLOW BETWEEN THE CATHODE AND THE ANODE TO BALANCE THE ION FLOW IN SAID CHAMBER PRODUCED BY SAID IONIZATION OF THE AIR THEREIN BY THE ALPHA EMITTER, AND MEANS CONNECTED DIRECTLY TO THE ANODE FOR PRODUCING AN ALARM IN RESPONSE TO REDUCTION IN THE ION FLOW IN THE CHAMBER.