Electronic radiant energy pyrometers

Claim 1

AN OPTICAL PYROMETER SYSTEM FOR MEASURING THE TEMPERATURE OF A BODY COMPRISING A VARIABLE BRIGHTNESS STANDARD FOR PRODUCING A BRIGHTNESS RELATED TO THE ELECTRIC CURRENT FLOW THERETHROUGH, ADJUSTABLE CALIBRATED POTENTIOMETRIC MEANS INCLUDING MEANS ADJUSTABLE RELATIVE TO A SCALE, SAID POTENTIOMETRIC MEANS BEING CONNECTED IN A CIRCUIT WITH SAID STANDARD IN SUCH A WAY AS TO PRODUCE AN ELECTRICAL OUTPUT SIGNAL RELATED TO THE ELECTRIC CURRENT FLOW THERETHROUGH AND TO THE SETTING OF SAID POTENTIOMETRIC MEANS RELATIVE TO SAID SCALE, A SOURCE PRODUCING A STANDARD ELECTRICAL SIGNAL, AND MEANS RESPONSIVE TO THE DIFFERENCE BETWEEN SAID STANDARD ELECTRICAL SIGNAL AND THE SIGNAL OUTPUT FROM SAID POTENTIOMETRIC MEANS, THE OUTPUTS OF SAID POTENTIOMETRIC MEANS AND THAT OF SAID STANDARD SOURCE BEING CONNECTED TO THE INPUT OF SAID MEANS RESPONSIVE TO THE DIFFERENCE BETWEEN SAID STANDARD ELECTRICAL SIGNAL AND THE SIGNAL OUTPUT FROM SAID POTENTIOMETRIC MEANS FOR CONTROLLING THE CURRENT THROUGH SAID VARIABLE BRIGHTNESS STANDARD AND THE POTENTIOMETER MEANS TO MAINTAIN THE DIFFERENCE BETWEEN SAID STANDARD ELECTRICAL SIGNAL AND THE SIGNAL OUTPUT FROM SAID POTENTIOMETRIC MEANS SUBSTANTIALLY AT ZERO, WHEREBY THE TEMPERATURE OF SAID BODY IS INDICATED BY SAID SCALE WHEN THE BRIGHTNESS OF SAID STANDARD AND THE BRIGHTNESS OF SAID BODY ARE EQUAL.