Copper-nickel thermocouple alloys

Claim 1

A THERMOCOUPLE ELEMENT CONSISTING OF AN ALLOY ESSENTIALLY COMPRISING A COPPER-NICKEL BASE WHOSE COPPERNICKEL RATIO IS WITHIN THE RANGE 62% COPPER/38% NICKEL TO 56% COPPER/44% NICKEL, HAVING A STABLE VOLTAGE/TEMPERATURE CHARACTERISTIC OVER THE TEMPERATURE RANGE OF FROM 0*C. TO 900*C. WHICH DIFFERS FROM THAT OF THE COPPERNICKEL BASE TO AN EXTENT PREDETERMINED BY INCLUSION IN THE ALLOY OF THE ADDITIONAL ELEMENTS INCLUDING ALUMINUM UP TO 4% AND HAVING AN EFFECT PER PERCENT OF 2700 MICROVOLTS AT 500*C., FOR ENHANCEMENT OF CORROSION RESISTANCE AND CHANGE OF SLOPE OF THE VOLTAGE/TEMPERATURE CHARACTERISTIC WITHOUT SUBSTANTIAL ALTERATION OF CURVATURE OF THAT CHARACTERISTIC OF THE COPPER-NICKEL BASE AND INCLUDING COBALT UP TO 2% AND HAVING AN EFFECT PER PERCENT OF 2750 MICROVOLTS AT 500*C. TO CHANGE THE SLOPE AND TO PROVIDE POSITIVE CORRECTION OF THE CURVATURE OF THE 400*C. AND ABOVE 600*C. OF THE VOLTAGE/TEMPERATURE CHARACTERISTIC OF THE COPPER-NICKEL BASE AND AT LEAST ONE ELEMENT FROM THE GROUP CONSISTING OF IRON, MANGANESE, SILICON, TITANIUM AND VANADIUM TO CHANGE THE SLOPE AND TO PROVIDE POSITIVE CORRECTION OF THE CURVATURE OF THE VOLTAGE/TEMPERATURE CHARACTERISTIC OF THE COPPER-NICKEL BASE, SAID ADDITIONAL ELEMENTS BEING PRESENT ENTIRELY IN SOLID SOLUTION AND NOT IN EXCESS OF LIMITS OF SOLID SOLUBILITY TO THE SUBSTANTIAL EXCLUSION OF THE FORMATION OF ANY OF SAID ADDITIONAL ELEMENTS INTO INTERGRANULAR SEGREGATES, AND HAVING THE BELOW-SPECIFIED EFFECT PER PERCENT OF ELEMENT IN MICROVOLTS AT 500*C., SAID ALUMINUM BEING PRESENT IN AN AMOUNT SUFFICIENTLY EFFECTIVE TO INCREASE THE CORROSION-RESISTANCE OF SAID ALLOY AND SAID COBALT AND SAID AT LEAST ONE OTHER ELEMENT BEING PRESENT IN AMOUNT SUFFICIENTLY EFFECTIVE TO MAKE THE VOLTAGE/TEMPERATURE CHARACTERISTIC OF SAID THERMOCOUPLE ELEMENT WITH RESPECT TO PLATINUM LESS NEGATIVE TO A PREDETERMINED EXTENT FROM THAT OF THE COPPER-NICKEL BASE: