Measurement and control of constituent potentials

Claim 1

IN A SYSTEM FOR MEASURING THE CARBON POTENTIAL OF THE ATMOSPHERE OF A CARBURIZING FURNACE SUPPLIED WITH A CARBURIZING AGENT, THE COMBINATION OF A CARBON-POTENTIAL DETECTING ELEMENT OF FERROUS METAL, AN ELECTRICAL CHARACTERISTIC OF WHICH VARIES WITH CHANGE IN CARBON CONTENT THEREOF, A BALANCEABLE ELECTRICAL NETWORK INCLUDING SAID DETECTING ELEMENT OF FERROUS METAL, AN ELECTRICAL CHARSPONSE TO UNBALANCE OF THE NETWORK FOR REBALANCING SAID NETWORK TO PROVIDE AN INDICATION OF CHANGE OF THE CARBON CONTENT OF SAID ELEMENT, AN ENCLOSURE FOR SAID DETECTING ELEMENT FOR CONFINING AROUND SAID ELEMENT THE ATMOSPHERE WHOSE CARBON POTENTIAL IS TO BE MEASURED, DECARBURIZING MEANS FOR PRODUCING WITHIN SAID ENCLOSURE AN ATMOSPHERE OF CARBON-REMOVING CHARACTER, MEANS FOR PERIODICALLY ACTUATING SAID DECARBURIZING MEANS AND FOR CONCURRENTLY DISCONNECTING SAID BALANCEABLE MEASURING CIRCUIT FROM SAID REBALANCEABLE MEANS, MEANS REPONSIVE TO THE UNBALANCE OF SAID MEASURING CIRCUIT IN A DIRECTION CORRESPONDING WITH REMOVAL FROM SAID DETECTING ELEMENT OF A SMALL FRACTION OF ITS TOTAL CARBON CONTENT FOR TERMINATION OF ACTUATION OF FIG -01 SAID DECARBURIZING MEANS TO RETURN TO SAID ELEMENT SAID ATMOSPHERE WHOSE CARBON POTENTIAL IS TO BE MEASURED AND AGAIN TO CONNECT THE OUTPUT OF SAID MEASURING CIRCUIT TO SAID REBALANCEABLE MEANS, ADDITIONAL MEANS FOR CONTROLLING SAID DECARBURIZING MEANS TO MAINTAIN SAID UNTIL THE CARBON CONTENT THEREOF HAS ATTAINED A PREDEUNTIL THE CARBON CONTENT THEREOF HAS ATTAINED A PREDETERMINED REPRODUCIBLE MINIMUM VALUE, MEANS OPERABLE UPON ATTAINMENT OF SAID REPRODUCIBLE VALUE FOR ADJUSTING SAID MEASURING NETWORK FOR AN OUTPUT CORRESPONDING WITH SAID REPRODUCIBLE MINIMUM VALUE, AND MEANS FOR PREVENTTING INTERRUPTION OF SAID CARBURIZING MEANS IMMEDIATELY FOLLOWING A CALIBRATING OPERATION AND UNTIL SUFFICIENT TIME HAS ELAPSED FOR THE RETURN TO SAID DETECTING ELEMENT OF A CARBON CONTENT CORRESPONDING WITH THAT OF SAID CARBURIZING ATMOSPHERE.