Devices for the measurement of weak magnetic fields by nuclear induction

Claim 1

A DEVICE FOR THE MEASUREMENT OF WEAK MAGNETIC FIELDS BY NUCLEAR INDUCTION WHICH COMPRISED, IN COMBINATION, A VESSEL, IN SAID VESSEL A SOLUTION WHEREIN THE SOLVENT CONTAINS A SAMPLE HAVING ATOMIC NUCLEI WITH AN ANGULAR MOMENTUM AND A MAGNETIC MOMENT BOTH DIFFERENT FROM ZERO AND THE SOLUTE CONTAINS A PARAMAGNETIC SUBSTANCE DISPLAYING, WHEN ONE OF ITS ELECTRONIC RESONANCE LINES IS SATURATED, THE OVERHAUSER-ABRAGAM EFFECT, AT LEAST ONE FIRST COIL SURROUNDING SAID SAMPLE TO CREATE THEREIN, FOR EVERY MEASUREMENT OPERATION, DURING A FIRST PERIOD, AN AUXILIARY MAGNETIC FIELD MAKING AN ANGLE DIFFERENKT FROM ZERO WITH THE MAGNETIC FIELD TO BE MEASURED, AT LEAST ONE SECOND COIL AND A SOURCE OF RADIOFREQUENCY POWER FOR EXCITING SAID SECOND COIL FOR CREATING IN SAID SAMPLE AN ELECTROMAGNETIC FIELD CAPABLE OF SATURATING SUCH AN ELECTRONIC RESONANCE LINE, IN ORDER TO ENSURE, DURING A SECOND PERIOD, FREE PRECESSION OF SAID ATOMIC NUCLEI ABOUT THE MAGNETIC DIELD TO BE MEASURED WITH A LARMOR FREQUENCY PROPORTIONAL TO THE INTENSITY OF SAID MAGNETIC FIELD TO BE MEASURED, THIS PRECESSION CREATING AN ELECTROMOTIVE FORCE AT THE SAME FREQUENCY IN SAID FIRST COIL, TWO MONOSTABLE MULTIVIBRATORS, A FIRST ONE AND A SECOND ONE, FOR THE SWITCHING AND THE FEED OF UNIDIRECTIONAL CURRENT TO SAID FIRST COIL SURROUNDING SAID SAMPLE, AN ADJUSTABLE CAPACITOR MOUNTED IN SERIES WITH SAID FIRST COIL TO FORM THEREWITH A FIRST OSCILLATORY CIRCUIT AT THE LARMOR FREQUENCY OF THE ATOMIC NUCLEI IN PRECESSION ABOUT THE MAGNETIC FIELD TO BE MEASURED, A PERIODMETER, AN AMPLIFIER SYSTEM ELECTRICALLY CONNECTED BETWEEN SAID FIRST OSCILLATORY CIRCUIT AND SAID PERIOD-METER A CONNECTING CABLE LEADING TO SAID FIRST COIL, A SECOND OSCILLATORY CIRCUIT CONSTITUTED BY THE INDUCTANCE OF SAID FIRST COIL AND THE PARASITIC CAPACITIES OF SAID FIRST COIL AND OF SAID CABLE, A DAMPING RESISTOR ARRANGED TO PERFORM THE CRITICAL DAMPING OF THE OSCILLATIONS THAT CAN BE CREATED IN SAID SECOND OSCILLATORY CIRCUIT, A MAIN RELAY HAVING A POSITION OF REST AND A WORKING POSITION OF REST, TO CONNECT SAID FIRST COIL VIA SAID CONNECTING CABLE WITH SAID ADJUSTABLE CAPACITOR AND HENCE WITH SAID PERIOD-METER, AND, IN ITS WORKING POSITION, TO CONNECT SAID FIRST COIL WITH SAID ITS WORKING POSITION, TO CONNECT SAID FIRST COIL WITH SAID DAMPING RESISTOR, SAID FIRST MONOSTABLE MULTIVIBRATOR BEING ADAPTED, WHEN IT IS TRIGGERED AT THE BEGINNING OF EVERY MEASUREMENT CYCLE, TO CONTROL THE SWITCHING OF SAID MAIN RELAY FROM ITS REST POSITION TO ITS WORKING POSITION FOR DAMPING OSCILLATIONS OCCURRING IN SAID FIRST COIL, AND A UNDIRECTIONAL CURRENT SOURCE, SAID SECOND MONOSTABLE MULTIVIBRATOR BEING MOUNTED TO BE TRIGGERED AFTER SAID FIRST MONOSTABLE MULTIVIBRATOR ON EVERY MEASUREMENT CYCLE AND BEING ADAPTED, WHEN TRIGGERED, TO CONNECT SAID FIRST COIL WITH SAID UNDIRECTIONAL CURRENT SOURCE FOR CREATING SAID OSCILLATORY MAGNETIC FIELD, THE TIMES FOR WHICH EACH OF THE TWO MONOSTABLE MULTIVIBRATORS REMAINS IN ITS UNSTABLE STATE BEING ADJUSTED IN SUCH MANNER THAT THE SECOND MONOSTABLE MULTIVIBRATOR RETURNS TO ITS INITIAL STABLE STATE BEFORE THE FIRST MONOSTABLE MULTIVIBRATOR RETURNS TO ITS INITIAL STABLE STATE, SAID SECOND MONOSTABLE MULTIVIBRATOR BEING ADAPTED, WHEN IT RETURNS TO ITS INITIAL STATE, TO DISCONNECT SAID UNDIRECTIONAL CURRENT SOURCE FROM SAID FIRST COIL, AND SAID FIRST MONOSTABLE MULTIVIBRATOR BEING ADAPTED, WHEN IT RETURNS TO ITS INITIAL STATE, TO CONTROL THE SWITCHING OF SAID MAIN RELAY FROM ITS WORKING POSITION TO ITS REST POSITION THUS CONNECTING SAID FIRST COIL WITH SAID PERIOD METER FOR MEASURING THE LARMOR FREQUENCY OF THE FREE PRECESSION OF SAID ATOMIC NUCLEI ABOUT THE MAGNETIC FIELD TO BE MEASURED.

Claim 2

A DEVICE FOR THE MEASUREMENT OF WEAK MAGNETIC FIELDS BY NUCLEAR INDUCTION WHICH COMPRISED, IN COMBINATION, A VESSEL, IN SAID VESSEL A SOLUTION WHEREIN THE SOLVENT CONTAINS A SAMPLE HAVING ATOMIC NUCLEI WITH AN ANGULAR MOMENTUM AND A MAGNETIC MOMENT BOTH DIFFERENT FROM ZERO AND THE SOLUTE CONTAINS A PARAMAGNETIC SUBSTANCE DISPLAYING, WHEN ONE OF ITS ELECTRONIC RESONANCE LINES IS SATURATED, THE OVERHAUSER-ABRAGAM EFFECT, AT LEAST ONE FIRST COIL SURROUNDING SAID SAMPLE TO CREATE THEREIN, FOR EVERY MEASUREMENT OPERATION, DURING A FIRST PERIOD, AN AUXILIARY MAGNETIC FIELD MAKING AN ANGLE DIFFERENKT FROM ZERO WITH THE MAGNETIC FIELD TO BE MEASURED, AT LEAST ONE SECOND COIL AND A SOURCE OF RADIOFREQUENCY POWER FOR EXCITING SAID SECOND COIL FOR CREATING IN SAID SAMPLE AN ELECTROMAGNETIC FIELD CAPABLE OF SATURATING SUCH AN ELECTRONIC RESONANCE LINE, IN ORDER TO ENSURE, DURING A SECOND PERIOD, FREE PRECESSION OF SAID ATOMIC NUCLEI ABOUT THE MAGNETIC DIELD TO BE MEASURED WITH A LARMOR FREQUENCY PROPORTIONAL TO THE INTENSITY OF SAID MAGNETIC FIELD TO BE MEASURED, THIS PRECESSION CREATING AN ELECTROMOTIVE FORCE AT THE SAME FREQUENCY IN SAID FIRST COIL, TWO MONOSTABLE MULTIVIBRATORS, A FIRST ONE AND A SECOND ONE, FOR THE SWITCHING AND THE FEED OF UNIDIRECTIONAL CURRENT TO SAID FIRST COIL SURROUNDING SAID SAMPLE, AN ADJUSTABLE CAPACITOR MOUNTED IN SERIES WITH SAID FIRST COIL TO FORM THEREWITH A FIRST OSCILLATORY CIRCUIT AT THE LARMOR FREQUENCY OF THE ATOMIC NUCLEI IN PRECESSION ABOUT THE MAGNETIC FIELD TO BE MEASURED, A PERIODMETER, AN AMPLIFIER SYSTEM ELECTRICALLY CONNECTED BETWEEN SAID FIRST OSCILLATORY CIRCUIT AND SAID PERIOD-METER A CONNECTING CABLE LEADING TO SAID FIRST COIL, A SECOND OSCILLATORY CIRCUIT CONSTITUTED BY THE INDUCTANCE OF SAID FIRST COIL AND THE PARASITIC CAPACITIES OF SAID FIRST COIL AND OF SAID CABLE, A DAMPING RESISTOR ARRANGED TO PERFORM THE CRITICAL DAMPING OF THE OSCILLATIONS THAT CAN BE CREATED IN SAID SECOND OSCILLATORY CIRCUIT, A MAIN RELAY HAVING A POSITION OF REST AND A WORKING POSITION OF REST, TO CONNECT SAID FIRST COIL VIA SAID CONNECTING CABLE WITH SAID ADJUSTABLE CAPACITOR AND HENCE WITH SAID PERIOD-METER, AND, IN ITS WORKING POSITION, TO CONNECT SAID FIRST COIL WITH SAID ITS WORKING POSITION, TO CONNECT SAID FIRST COIL WITH SAID DAMPING RESISTOR, SAID FIRST MONOSTABLE MULTIVIBRATOR BEING ADAPTED, WHEN IT IS TRIGGERED AT THE BEGINNING OF EVERY MEASUREMENT CYCLE, TO CONTROL THE SWITCHING OF SAID MAIN RELAY FROM ITS REST POSITION TO ITS WORKING POSITION FOR DAMPING OSCILLATIONS OCCURRING IN SAID FIRST COIL, AND A UNDIRECTIONAL CURRENT SOURCE, SAID SECOND MONOSTABLE MULTIVIBRATOR BEING MOUNTED TO BE TRIGGERED AFTER SAID FIRST MONOSTABLE MULTIVIBRATOR ON EVERY MEASUREMENT CYCLE AND BEING ADAPTED, WHEN TRIGGERED, TO CONNECT SAID FIRST COIL WITH SAID UNDIRECTIONAL CURRENT SOURCE FOR CREATING SAID OSCILLATORY MAGNETIC FIELD, THE TIMES FOR WHICH EACH OF THE TWO MONOSTABLE MULTIVIBRATORS REMAINS IN ITS UNSTABLE STATE BEING ADJUSTED IN SUCH MANNER THAT THE SECOND MONOSTABLE MULTIVIBRATOR RETURNS TO ITS INITIAL STABLE STATE BEFORE THE FIRST MONOSTABLE MULTIVIBRATOR RETURNS TO ITS INITIAL STABLE STATE, SAID SECOND MONOSTABLE MULTIVIBRATOR BEING ADAPTED, WHEN IT RETURNS TO ITS INITIAL STATE, TO DISCONNECT SAID UNDIRECTIONAL CURRENT SOURCE FROM SAID FIRST COIL, AND SAID FIRST MONOSTABLE MULTIVIBRATOR BEING ADAPTED, WHEN IT RETURNS TO ITS INITIAL STATE, TO CONTROL THE SWITCHING OF SAID MAIN RELAY FROM ITS WORKING POSITION TO ITS REST POSITION THUS CONNECTING SAID FIRST COIL WITH SAID PERIOD METER FOR MEASURING THE LARMOR FREQUENCY OF THE FREE PRECESSION OF SAID ATOMIC NUCLEI ABOUT THE MAGNETIC FIELD TO BE MEASURED.