Portable scintillation survey meter

Claim 1

A PORTABLE, VERY SENSITIVE DEVICE FOR DETECTING RADIOACTIVITY COMPRISING A SCINTILLATION DETECTOR INCLUDING A PHOSPHOR AND A PHOTOMULTIPLIER TUBE HAVING A SERIES OF SPACED DYNODES AND A COLLECTING ANODE; POWER SUPPLY MEANS FOR GENERATING AND APPLYING TO SAID PHOTOMULTIPLIER A PLURALITY OF DIFFERENT NEGATIVE POTENTIALS; MEANS FOR FORMING INTO A SINGLE INPUT PULSE THE PULSE COLLECTED AT SAID ANODE AND THAT RECEIVED AT THE NEXT ADJACENT DYNODE; MEANS FOR AMPLIFYING RECURRING INPUT PULSES, AND COUNTRATE MEANS CONNECTED TO SAID AMPLIFYING MEANS TO INDICATE THE RATE OF RECEIPT THEREOF; IN WHICH SAID MEANS FOR FORMING INPUT PULSES COMPRISES A SOURCE OF POTENTIAL CONNECTED TO ENERGIZE ALL OF SAID DYNODES SAVE THE DYNODE NEAREST SAID ANODE, A VARIABLE LOAD RESISTOR, A SOURCE OF ANODE VOLTAGE CONNECTED THROUGH SAID RESISTOR, A SOURCE OF ANODE VARIABLE CAPACITANCE MEANS CONNECTED BETWEEN SAID ANODE AND A POINT OF FIXED POTENTIAL, RESISTANCE MEANS CONNECTING SAID DYNODE ADJACENT THE ANODE TO SAID POINT OF FIXED POTENTIAL, AND AN OUTPUT CIRCUIT INCLUDING A PAIR OF EQUAL CAPACITORS, ONE OF SAID CAPACITORS BEING CONNECTED TO SAID ANODE, THE OTHER OF SAID CAPACITORS BEING CONNECTED TO SAID LAST-NAMED DYNODE, THE REMAINING TERMINALS OF SAID CAPACITORS BEING CONNECTED TOGETHER TO FORM ONE SIDE OF SAID OUTPUT CIRCUIT, SAID POINT OF CONSTANT POTENTIAL BEING THE OTHER SIDE OF SAID CIRCUIT.