Ionisation detector circuit

Claim 1

APPARATUS FOR MEASURING ORGANIC SUBSTANCE BY FLAME IONISATION TECHNIQUE IN INTEGRATING PRESENTATION COMPRISING, IN COMBINATION, FIRSTLY, A FLAME IONISATION DETECTOR, SECONDLY, A PRIMARY SOURCE OF ELECTRICAL ENERGY HAVING A POTENTIAL SUITABLE FOR THE FLAME IONISATION DETECTOR; THIRDLY, AN ELECTROMETER SUITABLE FOR THE AMPLIFICATION OF SIGNALS FROM SAID FLAME IONISATION DETECTOR ANDCHARACTERISED IN THAT IS HAS A HIGH INPUT RESISTANCE; FOURTHLY, A RECORDER SUITABLE FOR AND CONNECTED TO THE OUTPUT OF SAID ELECTROMETER; FIFTHLY, A CONDENSER CONNECTED ACROSS THE INPUT TO SAID ELECTROMETER WHERE THE CONDENSER CAPACITANCE IS SELECTED FROM THE RANGE FROM 0.001 TO 100 MICROFARADS AND THE ABOVE-MENTIONED INPUT RESISTANCE OF SAID ELECTROMETER IS CHOSEN TO BE SO HIGH AS TO MINIMISE LEAKAGE OF CHARGES FROM SAID CONDENSER THROUGH SAID ELECTROMETER; SIXTHLY, A BY-PASS SWITCH CONNECTED ACROSS SAID CONDENSER; AND CAPABLE OF BEING CLOSED FOR A FRACTION OF A SECOND BY CIRCUIT CLOSING MEANS ACTIVATED BY THE RECORDER AT A PRESELECTED POINT OF THE RECORDER PEN EXCURSION; AND SEVENTHLY, ALSO CONNECTED ACROSS THE INPUT TO SAID ELECTROMETER, A COMPENSATOR COMPRISING A VARIABLE RESISTOR HAVING A RESISTANCE SELECTED FROM THE RANGE FROM 10**12 TO 10**8 OHMS AND A SOURCE OF ELECTRICAL POTENTIAL SELECTED FROM THE RANGE FROM 5 TO 500 V. IN SUCH A MANNER THAT THE CURRENT PRODUCED FROM SAID COMPENSATOR AND OPPOSING THE SIGNAL CURRENT CAN BE ADJUSTED TO THE MAGNITUDE OF THE BACKGROUND CURRENT TO BE COMPENSATED FOR.