PORTABLE, FIXED EXTERNAL FIELD NAGNETOMETER FOR THE DETECTION OF MAGNETIC SIGNALS FROM SAMPLES AND THE ASSESSMENT OF THE AMOUNT OF MAGNETIC MATERIAL IN THE SAMPLE

Abstract

The present invention relates to a magnetometric device that measures the magnetic properties of a sample and whose most notable characteristic lies in that it is portable and highly precise, and can be used for the detection of a magnetic signal from nanostructures exposed to a fixed external magnetic field of excitation, of a unique value, it not being possible to alter the external magnetic field. The fixed external field can only be altered by modifying the device by means of exchanging the permanent magnets; however, once the device is sealed, this field does not vary. Different quantities of the same magnetic material may be placed in the sample holder, increasing the measurement signal; the present device can therefore determine the magnetic mass being measured following calibration of the magnetic material employed.

Claims

1. Portable magnetometry device is reliable and accurate, and allows to detect the presence of magnetic materials on a thin surface whether it is an organic surface, including polyethylene or cellulose, or an inorganic surface, including metals or their oxides, useful for measurements as they form. a fixed magnetic field comprising a magnetic system of at least 2 magnetic field generating means, preferably permanent magnets (6) and an alternating field gradient system by means of at least two magnetic field inducing means, preferably, coils that when applying a variable field alternately move the sample from an equilibrium position to produce a deflection in a piezoelectric sensor (9) and a mechanical system which is mobile and allows moving the arm with the piezoelectric away from the fixed coil system with permanent magnets allowing manipulation of the sample; wherein the present magnetometry device comprises a signal generator module or magnetic system or field gradient system; a motor module, control means and sensor means or mechanical system, and a power supply and amplification module; and signal generating means, microcontrollers, programmable pin, amplifiers, motor controllers and electronic distribution on a printed board.

2. The device of claim 1 wherein said mechanical system comprises a mechanical arm coupled (5) to a motor that allows the arm to rotate to remove the sample holder from the electromagnet cavity, and when it is rotated again, but in the opposite direction, allows the sample holder to re-enter the electromagnet cavity.

3. The device of claim 1 wherein said stepping motor is controlled by a driver circuit.

4. The device of claim 1 wherein said sample holder is anchored to a rigid and lightweight stem, made of non-magnetic material, preferably acrylic material.

5. The device of claim 4 wherein said stem is adhered to said piezoelectric sensor that is composed of ceramic material, which produces an electrical signal at the time of deformation, deflection or buckling in the axial axis of the piezoelectric.

6. The device of claim 1 wherein said at least two permanent magnets are arranged with opposite poles facing the cavity of the electromagnet.

Description

BREIF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1. Isometric view of the components of the portable magnetometer. Schematic description of the main components of the present AGFM alternating gradient magnetometry device. (1) sample holder, (2) rigid stem, (3) piezoelectric, (4) electrical signal output (+, -) of the piezoelectric, (5) arm support that is connected to a positioning motor, (6) magnet, permanent magnet, (7) fixed field electromagnet bracket, (8) coil core, (9) variable field inductor coils, (10) piezoelectric bracket.

[0013] FIG. 2. Isometric view of the assembled portable magnetometer. Description of the sealed magnetometer, that is, assembled. (1) sample holder, (2) rigid stem, (3) piezoelectric, (4) electrical signal output (+, -) of the piezoelectric, (5) arm support that is connected to a positioning motor, (8) coils core, (9) variable field inductor coils.

[0014] FIG. 3. Schematic flow diagram of the stages of the portable magnetometer controller circuit. Schematic flow diagram of the controller circuit stages of the portable fixed external applied field magnetometer for detecting magnetic signals from samples and evaluating the amount of magnetic material in a sample. (1) The sinusoidal signal generator. (2) Sinusoidal Signal Detector. (3) Stepper motors controlled and sensors (4) Power Source.

[0015] FIG. 4. Distribution of the electronic components of the circuit. Distribution of the electronic components of the circuit, that is, printed board.

[0016] FIG. 5. 3D model plan for the electromagnet support. 3D model plan for electromagnet support, i.e. permanent magnet support, coil support, coil core support and their respective spatial configurations.

DETAILED DESCRIPTION OF THE INVENTION

[0017] The present portable magnetometry device is reliable and accurate, and allows detecting the presence of magnetic materials on a thin surface, whether this surface is organic (polyethylene, cellulose, among others) or inorganic (metals, oxides, among others). For the measurement, the portable fixed field magnetometry device comprises a magnetic system of magnetic means, preferably permanent magnets (FIG. 1 (6)) and an alternating field gradient system by means of at least two magnetic field inducing means, preferably, coils that apply an alternating variable field, an applied field which will move the sample from its equilibrium position to produce a deflection in the piezoelectric sensor (FIG. 1 (9)). In order to manipulate the sample, a mechanical system will be used which is mobile and allows the arm with the piezoelectric to be moved away from the fixed system of coils with the permanent magnets.

[0018] The mechanical system comprises a mechanical arm coupled (FIG. 1 (5)) to a step motor, which rotates the arm to remove the sample holder from the electromagnet cavity, thus mounting the magnetic sample, that is, the specimen to be measured, and then the stepping motor turns again, but this time in the opposite direction to put the sample holder back into the electromagnet cavity. The step motor is controlled by a controller circuit shown in FIG. 3. The controls are programmed into the microprocessor through c ++ language.

[0019] The sample is mounted on a sample holder, which in turn is anchored to a rigid and light stem, made of non-magnetic material, preferably acrylic. In turn, the stem is attached to the piezoelectric that is composed of ceramic material, which produces an electrical signal at the time of deformation, deflection or buckling in the axial axis of the piezoelectric.

[0020] Being subjected to a fixed external field the sample is magnetized, in this case the fixed external magnetic field is produced by a permanent magnet, preferably at least two permanent magnets arranged with opposite poles facing the cavity of the electromagnet. As the sample is magnetized, it is susceptible to changes in the magnetic field applied by the inductor coils of an alternating gradient field. This alternating gradient field is driven by a core of ferromagnetic or ferrimagnetic material, specifically in this case a ferromagnetic iron core was used. The signal emission means are associated with the generation of the alternating magnetic field AGF produced by said coils, for this, a sinusoidal signal with a frequency between 10 Hz and 10 kHz is applied that is associated with the mass of the sample and a current capable of generating a field of magnitude that can vary from 10 to 100 Oe.

[0021] Due to the application of this disturbance in the magnetic field applied to the sample, the sample itself is subjected to a force that forces it to move, so the movement propagates through the rigid stem to the piezoelectric, which in turn, it will deform due to the transmission of this movement. In this way, the piezoelectric will deform, generating a signal proportional to this deformation, and therefore proportional to the magnetization of the sample.

[0022] In summary, the present magnetometry device comprises a signal generator module, a motor module, control means and sensor means, and a power supply and amplification module. In addition to signal generators, microcontrollers, programmable pin, amplifiers, motor controllers and electronic distribution on a printed board.