Alarm apparatus for gas testing, particularly carbon monoxide

Claim 1

GAS TESTING APPARATUS FOR DETECTING THE PRESENCE OF A PARTICULAR GAS CONSTITUENT IN AN ENCLOSED GASEOUS ATMOSPHERE BY THE USE OF A SELF-EXHAUSTING, LIGHT-AFFECTING VAPOR OR GAS WHICH IS EVOLVED WHEN SAID GAS CONSTITUENT IS PRESENT, SAID APPARATUS COMPRISING A CANISTER; A GASPERMEABLE TEST UNIT DISPOSED THEREIN; A BODY OF IODINE PENTOXIDE, SUPPORTED BY SAID TEST UNIT, CAPABLE OF REACTING WITH SAID GAS CONSTITUENT TO FORM AN EXHAUSTIBLE VAPOR OR GAS WHICH IS EVOLVED FROM THE REACTION OF SAID IODINE PENTOXIDE WITH SAID CONSTITUENT AND WHICH IS CAPABLE OF AFFECTING THE TRANSMISSION OF LIGHT; MEANS FOR INITIATING AND HASTENING THE REACTION BETWEEN SAID IODINE PENTOXIDE AND SAID CONSTITUENT; A LIGHT-TRANSMITTING EXHAUST CHAMBER COMMUNICATING WITH SAID CANISTER; A LAMP INTRODUCING LIGHT INTO SAID CHAMBER, A PHOTO-ELECTRIC CELL ARRANGED IN A MANNER TO RECEIVE LIGHT FROM THE LAMP THROUGH SAID EXHAUST CHAMBER; AN ELECTRONIC RELAY WHICH IS OPERATED BY SAID PHOTO-ELECTRIC CELL WHEN LIGHT RECEIVED BY SAID CELL DROPS TO A PREDETERMINED VALUE; MEANS FOR PASSING SAID GASEOUS ATMOSPHERE THROUGH SAID CANISTER AND EXHAUST CHAMBER; AND INDICATING MEANS OPERATED BY SAID RELAY.