Analyzer

Claim 1

IN AN ANALYZER INCLUDING A WHEATSTONE BRIDGE CIRCUIT HAVING RADIATION SENSATIVE ELEMENTS DISPOSED IN TWO ARMS THEREOF, AND A SOURCE OF ALTERNATING VOLTAGE APPLIED ACROSS OPPOSITE TERMINALS OF SAID BRIDGE; A POTENTIOMETER HAVING THE END TERMINALS THEREOF CONNECTED ACROSS SAID VOLTAGE SOURCE, THE CONTACTOR OF SAID POTENTIOMETER BEING MAINTAINED AT A POINT OF REFERENCE POTENTIAL; A PAIR OF VARIABLE IMPEDANCES CONNECTED IN SAID BRIDGE CIRCUIT; MOTOR-DRIVEN MEANS RESPONSIVE TO ELECTRICAL UNBALANCE OF SAID BRIDGE CIRCUIT FOR ADJUSTING THE VALUE OF AT LEAST ONE OF SAID IMPEDANCES TO RESTORE SAID BRIDGE TO BALANCE; AND MEANS FOR MINIMIZING THE EFFECT OF EXTRANEOUS ELECTRICAL SIGNALS WHICH MAY BE INTRODUCED INTO THE MOTOR CIRCUIT WHICH DO NOT TEND TO ACTUATE SAID MOTOR-DRIVEN MEANS COMPRISING, IN COMBINATION, MEANS FOR APPLYING THE UNBALANCE BRIDGE SIGNAL APPLIED TO SAID MOTOR-DRIVEN MEANS, AND MEANS FOR DETECTING THE COMPONENTS OF THE AMPLIFIED SIGNAL WHICH ARE NOT OF THE SAME FREQUENCY AND PHASE AS THE BRIDGE UNBALANCE SIGNAL DERIVED FROM SAID VOLTAGE SOURCE, WHEREBY THE CONTACTOR OF SAID POTENTIOMETER CAN BE ADJUSTED TO REDUCE TO A MINIMUM THE COMPONENTS OF SAID AMPLIFIED SIGNAL WHICH DO NOT ACTUATE SAID MOTOR-DRIVEN MEANS.