Magnetic fluxmeter

Claim 2

In a magnetic flux meter, a channel comprising in combination: an inductive loop transducer means for producing an electrical output signal that is proportional to the rate of change of the magnetic flux passing therethrough at a predetermined environmental location; controllable means connected to the output of said inductive loop transducer means for amplifying with high fidelity the electrical signal therefrom; means connected to the output of said controllable amplifying means for filtering said amplified electrical signal in such manner that a predetermined spurious component thereof is deleted therefrom; means connected to the output of said filtering means for integrating said filtered electrical signal; means connected to said integrating means for the discharging thereof in response to a predetermined reset signal; means effectively connected to the output of said integrating means for timely comparing the voltage of the output therefrom with a plurality of predetermined manually effected reference voltages and for producing the aforesaid predetermined reset signal whenever equal input voltages are compared thereby; means connected to the output of said voltage comparing means for manually effecting the varying of said reference voltages in accordance with predetermined voltage ranges; means connected to said reference voltage varying means, effectively connected to said voltage comparing means, and connected to said controllable amplifying means for selectively regulating the gain thereof; and means effectively connected to the aforesaid reference voltage varying means and the output of said integrating means of the aforesaid channel for reading out the integrated electrical signal therefrom on range scales thereof that are proportional thereto and optimum for the indication thereof in response to the aforesaid manually effected reference voltages.

Claim 3

The device of claim 1, wherein said inductive loop transducer means for producing an electrical output signal that is proportional to the rate of change of the magnetic flux passing therethrough at a predetermined environmental location comprises at least one coil of insulated electrical wire.

Claim 4

The device of claim 1, wherein said controllable means connected to the output of said inductive loop transducer means for amplifying with high fidelity the electrical signal theRefrom comprises a null detector nanovoltmeter amplifier.

Claim 5

The device of claim 1, wherein said means connected to the output of said controllable amplifying means for filtering said amplified electrical signal in such manner that a predetermined spurious component thereof is deleted therefrom comprises a band reject filter.

Claim 6

The device of claim 1, wherein said means connected to the output of said filtering means for integrating said filtered electrical signal comprises: a resistor having a pair of terminals, with one of the terminals thereof connected to the output of said filtering means; an operational amplifier connected to the other terminal of said resistor; and a capacitor connected in parallel with said operational amplifier.

Claim 7

The device of claim 1, wherein said means connected to said integrating means for discharging thereof in response to a predetermined reset signal comprises: a normally open switch effectively connected in parallel with said integrating means; and a solenoid connected to said switch in such manner as to effect the closure thereof in response to the aforesaid predetermined reset signal.

Claim 8

The device of claim 1, wherein said means effectively connected to the output of said integrating means for timely comparing the voltage of the output thereof with a plurality of predetermined reference voltages and for producing the aforesaid predetermined reset signal whenever equal input voltages are compared thereby comprises a Schmidt trigger.

Claim 9

The device of claim 1, wherein said means connected to the output of said voltage comparing means for manually effecting the varying of said reference voltages in accordance with predetermined voltage ranges comprises: a first direct current voltage; a first resistor having a pair of terminals; with one of the terminals thereof connected to said first direct current voltage; a second resistor having a pair of terminals, with one of the terminals thereof connected to said first direct current voltage; a third resistor having a pair of terminals, with one of the terminals thereof connected to said first direct current voltage; a first double contact single throw switch, with one of the contacts thereof connected to the other terminal of said first resistor, and with the throw thereof normally closed with said one contact; a second double contact single throw switch, with one of the contacts thereof connected to the other terminal of said second resistor, with the throw thereof normally closed with said one contact and connected to the other contact of the aforesaid first switch, and with the other contact thereof connected to the other terminal of said third resistor; a second direct current voltage; a third double contact single throw switch, with one of the contacts thereof disconnected, with the throw thereof normally closed with said disconnected contact and connected to said second direct current voltage, and with the other contact thereof connected to the control input of the aforesaid controllable amplifying means; a solenoid having a mechanical output and an electrical input, with the mechanical output thereof connected to the throws of said second and third switches for movement thereof into contact with the other contacts of said second and third switches in response to an electrical signal supplied to the electrical input thereof; a fourth double contact single throw switch, with one of the contacts thereof disconnected, with the throw thereof normally closed with said disconnected contact and connected to the output of the aforesaid voltage comparing means, and with the other contact thereof connected to the electrical input of said solenoid; and means connected to the throws of said first and fourth switches for the movement thereof into contact with the other contacts thereof, respectively.

Claim 10

The device of claim 1, wherein said means connected to said reference voltage varying means, effectIvely connected to said voltage comparing means, and connected to said controllable amplifying means for selectively regulating the gain thereof comprises: a latching solenoid; a first normally open switch having a movable arm and an electrical contact adapted for being contacted by said movable arm, with the movable arm thereof electrically connected to the output of said voltage comparing means and mechanically connected to the aforesaid manual reference voltage varying means, and with the electrical contact thereof connected to the input of said latching solenoid; a direct current voltage; and a second normally open switch having a movable arm and an electrical contact adapted for being contacted by said movable arm, with the movable arm thereof mechanically connected to the output of said latching solenoid, and with the electrical contact thereof effectively connected to the gain control input of the aforesaid controllable amplifying means.

Claim 11

The device of claim 1, wherein said means effectively connected to the aforesaid reference voltage varying means and the output of said integrating means of the aforesaid channel for reading out the integrated electrical signal therefrom on range scales thereof that are proportional thereto and optimum for the indication thereof in response to the aforesaid manually effected reference voltages comprises an automatic ranging-optimum resolution digital voltmeter.

Claim 12

The invention of claim 1, further characterized by: another channel substantially identical to the aforesaid channel, but with the inductive loop transducer means thereof disposed at a predetermined environmental location that is different from the predetermined environmental location of the inductive loop transducers of the aforesaid channel; and means connected between the outputs of said channels and the input of the aforesaid readout means for timely scanning the integrated electrical signals from said channels and successively supplying them to the input of said readout means for indication and recording thereof thereby in terms of magnetic flux parameters.