Viscosimeter

Claim 1

A VISCOSIMETER COMPRISING MEANS FOR SUPPORTING A COLUMN OF LIQUID TO BE TESTED AT A TESTING STATION, A PAIR OF COILS FORMING SENSING ELEMENTS VERTICALLY SPACED ALONG AND ENCIRCLING SAID COLUMN AND CAPABLE OF REACTING TO THE PRESENCE OF A TEST BODY IMMERSED THEREIN AT THE ELEVATION OF SAID COILS, TIMING MEANS, A STEPPING SWITCH HAVING AN OPERATING COIL AND SWITCH CONTACTS OPERATIVELY CONNECTED WITH SAID TIMING MEANS TO TURN THE SAME ON AND OFF IN RESPONSE TO SUCCESSIVE OPERATIONS OF THE STEPPING SWITCH, AN OSCILLATING SYSTEM INCLUDING AN ELECTRON FLOW DEVICE HAVING AN ANODE, A CATHODE AND A CONTROL ELEMENT, A TANK CIRCUIT INCLUDING SAID COILS DISPOSED IN PARALLEL RELATION WITH A TANK CONDENSER, SAID TANK CIRCUIT BEING CONNECTED BETWEEN THE ANODE OF SAID ELECTRON FLOW DEVICE AND GROUND, THROUGH A CONDENSER, A CONTROL CRYSTAL CONNECTED IN PARALLEL WITH A RESISTOR BETWEEN THE CONTROL ELEMENT OF THE ELECTRON FLOW DEVICE AND GROUND, THE CATHODE OF THE ELECTRON FLOW DEVICE BEING ISOLATED FROM GROUND BY A RESISTOR CONNECTED IN PARALLEL WITH A CONDENSER, THE TANK CONDENSER HAVING A CAPACITY SELECTED TO CAUSE THE SYSTEM NORMALLY TO OSCILLATE AND TO PRODUCE A POTENTIAL WITH RESPECT TO GROUND ON THE CATHODE OF THE ELECTRON FLOW DEVICE, SO LONG AS THE TEST BODY IS NOT IN POSITION TO BE SENSED BY EITHER OF SAID COILS, A BRIDGE CIRCUIT EMBODYING LIKE BRIDGE RESISTORS AND LIKE ELECTRON-FLOW VALVE UNITS FORMING THE LEGS OF THE BRIDGE CIRCUIT, SAID BRIDGE RESISTORS HAVING INTERCONNECTED AND GROUNDED ENDS AND GROUND REMOTE ENDS EACH CONNECTED WITH THE CATHODE OF A CORRESPONDING ELECTRON-FLOW VALVE UNIT, A POTENTIOMETER HAVING A RESISTANCE ELEMENT INTERCONNECTING THE ANODES OF THE ELECTRON-FLOW VALVE UNITS AND AN ADJUSTABLE CONTACT CONNECTED WITH THE OSCILLATING SYSTEM AT THE CONDENSER CONNECTED SIDE OF THE TANK CIRCUIT, THE CONTROL GRIDS OF THE ELECTRON-FLOW VALVE UNITS BEING RESPECTIVELY CONNECTED WITH THE CATHODE OF THE ELECTRON-FLOW DEVICE, THROUGH A CHOKE COIL AND WITH GROUND THROUGH A RESISTOR, WHEREBY THE BRIDGE CIRCUIT MAY BE BALANCED BY ADJUSTMENT OF THE POTENTIOMETER TO EQUALIZE THE POTENTIALS WITH RESPECT TO GROUND THAT APPEAR ON THE CATHODES OF THE BRIDGE ELECTRON-FLOW VALVE UNITS, WHEN THE OSCILLATING SYSTEM IS IN OSCILLATION, A TRANSISTOR FORMING AN AMPLIFIER HAVING ITS EMITTER AND ITS BASE CONNECTED RESPECTIVELY WITH THE CATHODES OF THE ELECTRON-FLOW VALVE UNITS, THE COLLECTOR OF SAID AMPLIFIER BEING CONNECTED WITH ONE END OF THE ACTUATING COIL OF THE STEPPING SWITCH, MEANS FOR APPLYING ELECTRICAL POTENTIAL BETWEEN THE OTHER END OF SAID ACTUATING COIL AND THE EMITTER OF THE TRANSISTOR, AND MEANS FOR APPLYING UNIDIRECTIONAL POTENTIAL ON THE OSCILLATING SYSTEM AT THE CONDENSER CONNECTED SIDE OF THE TANK CIRCUIT.