Apparatus comprising a signal output circuit responsive to a variable d-c voltage input

Claim 1

MONITORING APPARATUS COMPRISING, IN COMBINATION: (A) AT LEAST ONE IONIZATION CHAMBER SENSING UNIT DEFINING A CAPACITOR; (B) AN IONIZATION CHAMBER REFERENCE UNIT DEFINING A CAPACITOR AND CONNECTED IN SERIES WITH SAID AT LEAST ONE SENSING UNIT; (C) D.C. VOLTAGE SUPPLY MEANS CONNECTED ACROSS THE SERIES CIRCUIT CONSTITUTED BY SAID SENSING AND REFERENCE UNITS; (D) AN AMPLIFIER CIRCUIT HAVING AN INPUT TERMINAL; (E) NORMALLY OPEN SWITCH MEANS CONNECTED BETWEEN SAID INPUT TERMINAL AND THE JUNCTION BETWEEN SAID REFERENCE UNIT AND SAID AT LEAST ONE SENSING UNIT; AND (F) SWITCH CLOSING MEANS OPERATIVELY CONNECTED WITH SAID SWITCH MEANS FOR PERIODICALLY OPENING AND CLOSING THE LATTER IN A CONTINUAL MANNER SO AS TO CONDUCTIVELY CONNECT SAID JUNCTION TO SAID INPUT TERMINAL, THEREBY TO APPLY THE VOLTAGE APPEARING AT SAID JUNCTION TO SAID INPUT TERMINAL IN THE FORM OF A PLURALITY OF VOLTAGE PULSES WHOSE AMPLITUDES ARE PROPORTIONAL TO THE LOAD ON THOSE ELECTRODES OF SAID IONIZATION CHAMBER UNITS WHICH ARE CONNECTED TOGETHER AT SUCH JUNCTION.