CN103487770A - Passive detection device for measuring full tensor information of space magnetic field gradient - Google Patents

Abstract

The invention discloses a passive detection device for measuring full tensor information of space magnetic field gradient. The passive detection device is formed by seven three-axis coil magnetic sensors, a horizontal base and signal wire connectors according to the basic principle of Faraday's law of electromagnetic induction, wherein the seven three-axis coil magnetic sensors are distributed in an orthometric mode. The direct measurement of the full tensor information of the space magnetic field gradient is achieved through a connection mode that the coil sensors are reversely connected in series and original point symmetry layout structural design. The passive detection device has the advantages of overcoming the technical defect that a traditional magnetic field gradient measuring device can be only used for measuring unidirectional gradient information, improving space consistency and information integrity of magnetic-field component measurement, reducing the noise of magnetic field gradient signals through the symmetrical layout and routing, and enabling a brand new magnetic gradiometer calibration method to be achieved through the arrangement of an induction area fine tuning structure. The passive detection device with the function of measuring the abundant magnetic field gradient tensor information is widely and urgently applied to the fields of magnetic target location, medical tumor inspection, geological exploration, nondestructive examination and the like.

Description

A kind of passive detection device for the full tensor information of measurement space magnetic field gradient

Technical field

The present invention relates to Zhong magnetic field, magnetic measurement field and gradient information measuring method and technology, specifically, it is a kind of Faraday's electromagnetic induction law of utilizing, by the connect passive detection device of the full tensor information of measurement space magnetic field gradient that the coil pickoff connection form of reversal connection forms of coil, in Non-Destructive Testing, medical research, the fields such as magnetic target location have a wide range of applications.

Background technology

Magnetic field is vector field, and magnetic field gradient is the derivative that magnetic field versus is moved, along space a direction move infinitesimal apart from the time, the variable quantity in magnetic field.Because the principle of the angle considered a problem and practical application is different, generally speaking, again magnetic field gradient is divided into to magnetic field scalar (after each component vector is synthetic, getting Vector Mode) gradient, magnetic vector gradient and magnetic field gradient tensor.

Specifically, in hypothesis space, the magnetic field intensity of certain point is H=(H _x, H _y, H _z), its magnetic field scalar gradient is defined as:

$g=\frac{d\left|H\right|}{\mathrm{dr}}---\left(1\right)$

In formula (1),

r is the distance on assigned direction;

The magnetic vector gradient is defined as:

${\mathrm{<figure-callout\; id="3"\; label="g"\; filenames="HDA00003793373300031.png"\; state="\{\{state\}\}">g</figure-callout>}}_3=\left(\begin{array}{c}{g}_x\\ g_y\\ g_z\end{array}\right)=\frac{\mathrm{dH}}{\mathrm{dr}}=\left(\begin{array}{c}\frac{{\mathrm{dH}}_x}{\mathrm{dr}}\\ \frac{{\mathrm{dH}}_y}{\mathrm{dr}}\\ \frac{{\mathrm{dH}}_z}{\mathrm{dr}}\end{array}\right)---\left(2\right)$

The magnetic field gradient tensor refers to the tribasilar rate of change of magnetic field along space coordinates, and magnetic vector is to the space vector differentiate.Its mathematics differentiating operator expression-form is:

$G=\frac{\&PartialD;H}{\&PartialD;r}=(n\&CenterDot;{\&dtri;H}_x)i+(n\&CenterDot;{\&dtri;H}_y)j+(n\&CenterDot;{\&dtri;H}_z)k---\left(3\right)$

In formula (3), i, j, k is respectively rectangular coordinate system in space respectively along x, y, the base of z direction.Formula (3) can also the gradient tensor of being write as of equal valuely matrix form have:

$G=\left(\begin{array}{ccc}{\&PartialD;}_x{H}_x& {\&PartialD;}_y{H}_x& {\&PartialD;}_z{H}_x\\ {\&PartialD;}_x{H}_y& {\&PartialD;}_y{H}_y& {\&PartialD;}_z{H}_y\\ {\&PartialD;}_x{H}_z& {\&PartialD;}_y{H}_z& {\&PartialD;}_z{H}_z\end{array}\right)---\left(4\right)$

In formula (4), each element of matrix the q component that the physical significance of representative is Mou Dian magnetic field, space is along the rate of change of p direction.

According to above-mentioned basic physics definition, can pass through at space diverse location configuration Magnetic Sensor, and the result that Magnetic Sensor is measured is carried out computing or take suitable circuit connecting mode to obtain gradient information.By the degree of enriching of gradient information, gradiometer can be divided into: scalar gradiometer, vector gradiometer, part tensor magnetic field gradient meter and full tensor magnetic field gradient meter.According to formula (1)～(4), the difference that can analyze above four kinds of magnetic field gradient meters is to measure the degree of enriching of field signal, and information is abundanter, and measurement mechanism is more complicated.

At present, there has been application widely in magnetic field gradient meter scientific research, engineering practice field at home and abroad.Superconducting quantum interference device (SQUID) (the Superconductivity Quantum Interference Device of U.S. Te Ruisitan technology company development, SQUID) the made magnetic field gradient meter caused, the Grad of three, magnetic field component on three directions can be measured, but the plane gradient Tensor measuring can only be realized; Australian Union's science industrial research tissue (CSIRO) is cooperated with five ore deposit companies, developing the full tensor magnetic gradiometer of aviation (the Glass Earth Tensor Magnetic Airborne Gradiometer that uses SQUID, GETMAG), for geologic examination and search for mineral deposit; 2004, Jena, Germany physics high-tech research institute (Institute for Physical High-Technology, IPHT) was used SQUID to carry out the flight test of magnetic tensor system in South Africa, and the data that pilot fight is obtained are made a H _xx, H _xy, H _xz, H _yy, H _yz, H _zzplanimetric map, measure the about 100km of area ², belong to first in the world, but related data holds in close confidence.

Domestic research mainly concentrates on geologic prospecting at present, medical science detects.Also start at present to have some preliminary reports towards the magnetic target location, but the report of experimental result aspect seldom.Harbin Engineering University has proposed the easy configuration of vector magnetometer for the magnetic target orientation problem, but can only measure the part component in nine components of magnetic field gradient tensor, is not full tensor gradiometer.Since " 15 ", more domestic Research Teams have been developed HC-07 helium light pump magnetic apparatus, aviation magnetic field horizontal gradient instrument, hyperchannel airborne magnetic survey numeral auto-compensation instrument etc. in succession.Development work and the system integration of magnetic air field vector gradiometry that hyperchannel airborne magnetic survey numeral auto-compensation instrument and data are included integral system obtain certain progress.

In above research, magnetic field gradient meter used can be divided into indirect measurement and directly measure by the acquisition pattern of gradient signal.Indirectly measure gradiometer, i.e. electronic gradient meter.It refers in space at a distance of for 2 of d, placing respectively Magnetic Sensor, by the measurement value sensor H collected ₁and H ₂after doing difference, divided by distance d, carry out approximate magnetic field gradient information.According to theory of errors, the drawback of this metering system is that the magnetic field due to sensor measurement exists error, and field signal subtracts each other and the error of the magnetic field gradient signal that calculates can be very large, to such an extent as to hour can't measure at magnetic field gradient at all.

Summary of the invention

In order to address the above problem, the present invention proposes a kind of full tensor field detecting device that Faraday's electromagnetic induction law used the coil Magnetic Sensor of appropriate configuration to make as ultimate principle of take, sensor type of attachment by the series connection reversal connection, offset the background magnetic field common-mode signal, retain gradient signal, after this sniffer is calibrated under uniform magnetic field, precision is higher.

A kind of passive detection device for the full tensor information of measurement space magnetic field gradient, comprise main body probe portion, horizontal adjustable base and signal passing interface;

Wherein, the main body probe portion is arranged on horizontal adjustable base, is supported by horizontal adjustable base, and regulates level by horizontal adjustable base; The main body probe portion consists of seven identical probe units of structure, is respectively used to gather the magnetic vector information of seven the basic sampled points in space;

Seven identical probe units of structure form by the large small circular pcb board of the grade that upwards is furnished with coil three weeks, and three pcb boards vertically are connected in twos, and the concyclic heart, form the probe unit of mutually orthogonal structure; Make seven unit be respectively unit A, unit B, unit C, cells D, unit E, unit F and unit G; The central point of unit A of usining is set up rectangular coordinate system in space O(x, y, z as initial point), seven relative origin symmetry settings of probe unit; Wherein, the central point of unit B and unit C lays respectively on the positive negative direction of x axle, and with unit, A is connected; Cells D and unit E lay respectively on the positive negative direction of y axle, and with unit, A is connected; Unit F and unit G lay respectively on the positive negative direction of z axle, and with unit, A is connected; And in each probe unit, three pcb boards lay respectively in the plane that x axle in rectangular coordinate system in space, y axle form, in the plane formed with x axle, z axle, and in the plane that forms of y axle, z axle;

In the main body probe portion of said structure, between the coil on the equidirectional pcb board of origin symmetry, by the series connection reversal connection, directly to export magnetic field gradient information, be specially: make inboard one end of coil on three pcb boards of each probe unit as the acquisition of signal end, the outside one end is as signal output part; Thus, by unit B with in unit C, cells D with in unit E, unit F with in unit G in twos on symmetrical pcb board homonymy the signal input part of coil by wire, connect, signal output part all is wired to a signal passing interface; The signal passing interface is for the transmission weak voltage signals corresponding with magnetic field gradient and central magnetic field vector strength; Can obtain thus the measuring-signal of center three tunnel magnetic-field components and magnetic field component of tensor.

The invention has the advantages that:

1, passive detection device of the present invention, in the magnetic measurement field, leading the realization used the device of one to carry out the detection of full tensor Vector Magnetic Field gradient;

2, passive detection device of the present invention, the frequency band range that can measure magnetic field is wide, has the accuracy at zero point that the zeroing calibration function carried has guaranteed sniffer.

3, passive detection device of the present invention, the cabling layout by symmetrical expression reaches and has extremely low quiescent operation noise level (being less than 1uT), and the output of magnetic field gradient signal can reach the magnitude of hundreds of microvolt, and signal to noise ratio (S/N ratio) is higher than 50dB.

The accompanying drawing explanation

Fig. 1 is main body probe portion configuration schematic diagram in passive detection device of the present invention;

Fig. 2 is probe unit structural representation in passive detection device of the present invention;

Coil layout type schematic diagram on pcb board in the probe unit that Fig. 3 is the main body probe portion;

Fig. 4 cuts off the connected mode schematic diagram between coil in probe unit;

Fig. 5 is main body probe portion one-piece construction schematic diagram in passive detection device of the present invention;

Fig. 6 be in passive detection device of the present invention about on same magnetic field component face between the probe unit of origin symmetry between coil the series connection reversal connection the connection mode schematic diagram;

Fig. 7 (a) offers position view for slot on the first pcb board of probe portion in passive detection device of the present invention;

Fig. 7 (b) offers position view for slot on the second pcb board of probe portion in passive detection device of the present invention;

Fig. 7 (c) offers position view for slot on the 3rd pcb board of probe portion in passive detection device of the present invention;

When Fig. 8 (a) adopts connecting method for main body probe portion in passive detection device of the present invention, main board plug structure and slot starting position schematic diagram;

When Fig. 8 (b) adopts connecting method for main body probe portion in passive detection device of the present invention, laterally board plug structure and slot are offered position view;

When Fig. 8 (c) adopts connecting method for main body probe portion in passive detection device of the present invention, vertically board plug structure and slot are offered position view.

In figure:

1-probe unit 2-PCB plate 3-coil 4-via hole

5-fine setting slot 6-connecting lead wire

Embodiment

Below in conjunction with accompanying drawing, the present invention is described in further detail.

The present invention, for the passive detection device of the full tensor information of measurement space magnetic field gradient, comprises main body probe portion, horizontal adjustable base and signal passing interface.Wherein, the main body probe portion is arranged on horizontal adjustable base, by horizontal adjustable base, supported, and by horizontal adjustable base when the full tensor information of main body probe portion measurement space magnetic field gradient, the main body probe portion is carried out to the Level tune operation.

Described main body probe portion consists of seven identical probe units 1 of structure, is respectively used to gather the magnetic vector information of seven the basic sampled points in space, as shown in Figure 1.

The identical probe unit 1 of seven structures is by the Board such as Circuit such as 2(Printed such as large small circular pcb board such as grade that upwards is furnished with coil 3 three weeks, printed circuit board (PCB)) form, three pcb boards 2 vertically are connected in twos, and the concyclic heart, form thus the probe unit 1 of mutually orthogonal structure, as shown in Figure 2.Coil 3 layout type in seven probe units 1 on each PCB are identical, all adopt two centers of circle loop expansion pattern, as shown in Figure 3, coil 3 is enclosed around n on pcb board 2, and n the half coil 3 that n turn coil 3 forms in the center line both sides of pcb board 2 has respectively public center of circle A and two centers of circle of public center of circle B, can guarantee thus continuity and the homogeneity of coil 3.Three pcb boards 2 of said structure are adopting mutually orthogonal mode to be connected, and in connection procedure, 2 of the pcb boards of two mutual quadratures will inevitably make the coil 3 on one of them pcb board 2 disconnect in junction; Therefore in the pcb board 2 of two mutual quadratures, on the complete pcb board 2 of junction coil 3, the via hole that runs through pcb board 2 two sides is offered in coil 3 inside at the junction correspondence position, on the pcb board 2 disconnected at junction coil 3 thus, disconnect between the two ends of coil 3 correspondences, by connecting lead wire 6, through corresponding via hole, be connected, as shown in Figure 4, guarantee thus coil 3 integrity degrees on each pcb board 2, and connecting lead wire 6 adopts enameled wires, prevent crosstalking of induced voltage signal between mutually orthogonal coil 3.

Connected by seven probe units 1 by said structure, form the cylinder probe portion, as shown in Figure 5, concrete connected mode is: make seven unit be respectively unit A, unit B, unit C, cells D, unit E, unit F, unit G; The central point of unit A of usining is set up rectangular coordinate system in space O(x, y, z as initial point), seven relative origin symmetry settings of probe unit 1; Wherein, the central point of unit B and unit C lays respectively on the positive negative direction of x axle, and with unit, A is connected; Cells D and unit E lay respectively on the positive negative direction of y axle, and with unit, A is connected; Unit F and unit G lay respectively on the positive negative direction of z axle, and with unit, A is connected; And in each probe unit 1, three pcb boards 2 lay respectively in the plane that x axle in rectangular coordinate system in space, y axle form, in the plane formed with x, z, and in the plane that forms of y, z.

In the main body probe portion of said structure, directly export magnetic field gradient information with 3 of the coils on the equidirectional pcb board 2 of origin symmetry by the series connection reversal connection, as shown in Figure 6, be specially: make inboard one end of coil 3 on three pcb boards 2 of each probe unit 1 as the acquisition of signal end, the outside one end is as signal output part; Thus, by unit B with in unit C, cells D with in unit E, unit F with in unit G in twos on symmetrical pcb board 2 homonymies the signal input part of coil 3 by wire, connect, signal output part all connects a signal passing interface by wire; The signal passing interface is for the transmission weak voltage signals corresponding with magnetic field gradient and central magnetic field vector strength; The signal passing interface is located on the perpendicular bisector of the signal output part line of coil 3 on two symmetrical pcb boards 2.Can obtain thus the measuring-signal of three magnetic field, tunnel component of tensors; The PCB coil 3 at initial point place is measured probe portion main center's point magnetic vector information.

Be designed with slot in the present invention on three pcb boards 2, by the splicing mode form probe unit 1, can guarantee the concentricity of three pcb boards 2 in each probe unit 1, as Fig. 7 (a), 7(b), 7(c) as shown in, be specially:

Make three pcb boards 2 be respectively the first pcb board, the second pcb board and the 3rd pcb board; All take central point as round dot on three pcb boards 2,2 of pcb boards, set up in the plane plane right-angle coordinate;

Wherein, in the first pcb board, y axle negative direction both sides are symmetrical slot A and the slot B that is parallel to the y axle that have respectively; Y axle positive dirction has the slot C overlapped with the y axle; And the end of slot A, slot B and slot C connects the first pcb board edge, cut off coil 3; The other end all is positioned on the x axle.

In the second pcb board, y axle negative direction both sides are symmetrical slot D and the slot E that is parallel to the y axle that have respectively; Also have the slot F overlapped with the y axle in y axle negative direction; And slot D, slot E and slot F mono-end connect the second pcb board edge, cut off coil 3, the other end all is positioned on the x axle.

In the 3rd pcb board, in the 3rd pcb board center, have the axle with x, the slot G that the y axle overlaps respectively and slot H, form the cross slot; Positive negative direction at the x axle has slot I, the slot J overlapped with the x axle; Positive negative direction at the y axle has slot K, the slot L overlapped with the y axle; And slot I, slot J, slot K and slot L mono-end connect the 3rd pcb board edge, cut off coil; And slot I equates to the distance of y axle with slot A, slot B in the first pcb board with the distance of the slot J other end to the y axle; The other end of slot K and slot L to the distance of x axle with slot D, slot E in the second pcb board to the y wheelbase from equating; And the length of slot G equates with slot B spacing with slot A in the first pcb board; The length of slot H with slot D in the second pcb board, with slot E spacing, equate.

During interpolation, by three parts being separated by slot A and slot B in the first pcb board, slot I, slot G in respectively corresponding the 3rd pcb board insert and splice with slot J; By three parts of being separated by slot D and slot E in the second pcb board, slot K, slot H, slot L in respectively corresponding the 3rd pcb board insert splicing subsequently, and the slot C insertion in corresponding the first pcb board of slot F is spliced, and finally form whole probe unit 1.

Because the slot on above-mentioned the first pcb board, the second pcb board and the 3rd pcb board has cut off coil 3, therefore, after the first pcb board, the second pcb board and the splicing of the 3rd pcb board, on the first pcb board, between the symmetrical two ends of coil 3 that cut off with slot B by slot A, by connecting lead wire 6, be connected; In the second pcb board, between the symmetrical two ends of coil 3 that cut off with slot E by slot D, by connecting lead wire 6, be connected.And in the first pcb board, between the symmetrical two ends of coil 3 that cut off by slot C owing to being intercepted by the second pcb board, between the symmetrical two ends of coil 3 that therefore cut off by slot C, can be by connecting lead wire 6 through in the second pcb board, be positioned at corresponding coil 3 inside, slot place and run through the via hole of the second pcb board two sides and connected.In like manner, in the second pcb board, between the symmetrical two ends of coil 3 that cut off by slot F, can be by connecting lead wire 6 through in the first pcb board, be positioned at corresponding coil 3 inside, slot place and run through the via hole of the first pcb board two sides and connected; In the second pcb board, between the symmetrical two ends of coil 3 that cut off by slot I, slot J, can be by connecting lead wire 6 through in the first pcb board, be positioned at corresponding coil 3 inside, slot place and run through the via hole of the first pcb board two sides and connected; Between the symmetrical two ends of coil 3 that cut off by slot K, slot L, can be by connecting lead wire 6 through in the second pcb board, be positioned at corresponding coil 3 inside, slot place and run through the via hole of the second pcb board two sides and connected; Guarantee thus the integrity degree of coil 3.Slot on above-mentioned three pcb boards can be used as fine setting slot 5 simultaneously, there is one fixed width, can carry out the spacing adjustment of connecting lead wire 6, realize directly sniffer being calibrated zero point from hardware point of view, to guarantee the accuracy of Magnetic Gradient Measurement, reduce the intrinsic systematic error of surveying instrument.

Simultaneously, when guaranteeing in each probe unit 1 three pcb board 2 concentricitys, guarantee the right alignment of 1 of seven probe unit, as Fig. 8 (a), 8(b), 8(c) as shown in, the 3rd pcb board in the unit A of aforementioned body probe portion layout structure, unit B, unit C, cells D, unit E is designed to the main plate of coplanar integrative-structure; Groove G two ends on the 3rd pcb board in unit A are communicated with groove J and groove I on the 3rd pcb board in unit B and unit C respectively simultaneously; Groove H two ends are communicated with groove L with the groove K on the 3rd pcb board in cells D and unit E respectively.The second pcb board in unit A, unit B, unit F and the first pcb board in unit C are designed to the horizontal plate of coplanar integrative-structure.The second pcb board in the first pcb board in unit A, unit B and unit A, unit F is designed to vertical plate of coplanar integrative-structure; Thus horizontal plate is inserted in main plate slot transversely by horizontal plate one side coupling; In slot on vertical plate is vertical by the main plate of horizontal plate opposite side coupling insertion; In seven probe units 1, all the other plates carry out interpolation according to the interpolation of 2 of three pcb boards in above-mentioned each probe unit 1.

When adopting the full tensor information of passive detection device measurement space magnetic field gradient of said structure, by following step, complete:

Step 1: make the main body probe portion parallel with surface level by horizontal adjustable base, be about to seven pcb boards 2 being parallel to each other in seven probe units 1 parallel with surface level.

Step 2: the zero point of regulating sniffer under the constant amplitude alternating magnetic field;

Sniffer is placed in to the constant amplitude alternating magnetic field, makes the x axle of sniffer parallel with magnetic direction, it is zero that the spacing of regulating connecting lead wire 6 on sniffer fine setting slot 5 makes the axial sniffer output voltage of x; Change the direction of sniffer, make respectively the y axle of sniffer parallel with magnetic direction with the z axle, repeat above-mentioned steps until gradient and x axle, y axle, the axial sniffer output voltage of z are all zero.

Step 3: measure and record gradient tensor and the magnetic vector information for the treatment of measuring magnetic field;

Sniffer is placed in and treats measuring magnetic field, by horizontal adjustable base, make the main body probe portion parallel with surface level; And measure successively and recording (4) in because the full tensor in magnetic field causes induced voltage signal amplitude V _gwith the corresponding voltage signal amplitude of the magnetic vector at initial point place V _h:

$V_G=\left(\begin{array}{ccc}{V}_{\mathrm{xx}}& V_{\mathrm{yx}}& V_{\mathrm{zx}}\\ V_{\mathrm{xy}}& V_{\mathrm{yy}}& V_{\mathrm{zy}}\\ V_{\mathrm{xz}}& V_{\mathrm{yz}}& V_{\mathrm{zz}}\end{array}\right)---\left(6\right)$

$V_H=\left(\begin{array}{c}{V}_x\\ V_y\\ V_z\end{array}\right)$

And electric voltage frequency f; The value of f is identical with tested field frequency.

Step 4: according to information of voltage inverting gradient tensor and the Magnetic Field measured:

The measuring magnetic field for the treatment of for the initial point place:

$H_o=\left(\begin{array}{c}{H}_{\mathrm{ox}}\\ H_{\mathrm{oy}}\\ H_{\mathrm{oz}}\end{array}\right)\sin \left(2\mathrm{\&pi;ft}\right)---\left(8\right)$

According to the physics expression formula of Faraday's electromagnetic induction law:

In formula, the number of turn that n is inductive coil 3,

for the magnetic flux of every circle inductive coil 3, the sectional area that A is inductive coil 3, μ ₀for permeability of vacuum.

The amplitude that can obtain the induced voltage at main body probe portion initial point place is:

$V_H=\left(\begin{array}{c}{V}_x\\ V_y\\ V_z\end{array}\right)=-\mathrm{nA}{\mathrm{\&mu;}}_0\left(\begin{array}{c}{\mathrm{dH}}_{\mathrm{ox}}/\mathrm{dt}\\ {\mathrm{dH}}_{\mathrm{oy}}/\mathrm{dt}\\ {\mathrm{dH}}_{\mathrm{oz}}/\mathrm{dt}\end{array}\right)=-2\mathrm{\&pi;fnA}{\mathrm{\&mu;}}_0\left(\begin{array}{c}{H}_{\mathrm{ox}}\\ H_{\mathrm{oy}}\\ H_{\mathrm{oz}}\end{array}\right)---\left(9\right)$

The amplitude for the treatment of measuring magnetic field can be expressed as with measuring-signal:

$H_o=\left(\begin{array}{c}{H}_{\mathrm{ox}}\\ H_{\mathrm{oy}}\\ H_{\mathrm{oz}}\end{array}\right)=\left(\begin{array}{c}{V}_x\\ V_y\\ V_z\end{array}\right)/-2\mathrm{\&pi;fnA}{\mathrm{\&mu;}}_0---\left(10\right)$

According to formula (4) and formula (6) and above-mentioned derivation, in like manner can obtain:

$G=\left(\begin{array}{ccc}{\&PartialD;}_x{H}_x& {\&PartialD;}_y{H}_x& {\&PartialD;}_z{H}_x\\ {\&PartialD;}_x{H}_y& {\&PartialD;}_y{H}_y& {\&PartialD;}_z{H}_y\\ {\&PartialD;}_x{H}_z& {\&PartialD;}_y{H}_z& {\&PartialD;}_z{H}_z\end{array}\right)\&ap;\left(\begin{array}{ccc}{V}_{\mathrm{xx}}& V_{\mathrm{yx}}& V_{\mathrm{zx}}\\ V_{\mathrm{xy}}& V_{\mathrm{yy}}& V_{\mathrm{zy}}\\ V_{\mathrm{xz}}& V_{\mathrm{yz}}& V_{\mathrm{zz}}\end{array}\right)/-4\mathrm{d\&pi;fnA}{\mathrm{\&mu;}}_0$

In formula, the diameter that d is the peripheral mechanical dimension in coil Unit 3 outline line.

Claims (7)

1. the passive detection device for the full tensor information of measurement space magnetic field gradient, comprise main body probe portion, horizontal adjustable base and signal passing interface;

Wherein, the main body probe portion is arranged on horizontal adjustable base, is supported by horizontal adjustable base, and regulates level by horizontal adjustable base; The main body probe portion consists of seven identical probe units of structure, is respectively used to gather the magnetic vector information of seven the basic sampled points in space;

Seven identical probe units of structure form by the large small circular pcb board of the grade that upwards is furnished with coil three weeks, and three pcb boards vertically are connected in twos, and the concyclic heart, form the probe unit of mutually orthogonal structure; Make seven unit be respectively unit A, unit B, unit C, cells D, unit E, unit F, unit G; The central point of unit A of usining is set up rectangular coordinate system in space O(x, y, z as initial point), seven relative origin symmetry settings of probe unit; Wherein, the central point of unit B and unit C lays respectively on the positive negative direction of x axle, and with unit, A is connected; Cells D and unit E lay respectively on the positive negative direction of y axle, and with unit, A is connected; Unit F and unit G lay respectively on the positive negative direction of z axle, and with unit, A is connected; And in each probe unit, three pcb boards lay respectively in the plane that x axle in rectangular coordinate system in space, y axle form, in the plane formed with x axle, z axle, and in the plane that forms of y axle, z axle;

In the main body probe portion of said structure, between the coil on the equidirectional pcb board of origin symmetry, by the series connection reversal connection, directly to export magnetic field gradient information, be specially: make inboard one end of coil on three pcb boards of each probe unit as the acquisition of signal end, the outside one end is as signal output part; Thus, by unit B with in unit C, cells D with in unit E, unit F with in unit G in twos on symmetrical pcb board homonymy the signal input part of coil by wire, connect, signal output part all is wired to a signal passing interface; The signal passing interface is for the transmission weak voltage signals corresponding with magnetic field gradient and central magnetic field vector strength; Can obtain thus the measuring-signal of center three tunnel magnetic-field components and magnetic field component of tensor.

2. a kind of passive detection device for the full tensor information of measurement space magnetic field gradient as claimed in claim 1, it is characterized in that: the coil layout mode in described seven probe units on each PCB is identical, coil is enclosed around n on pcb board, and n the half coil that the n turn coil forms in the center line both sides of pcb board have respectively public center of circle A and two centers of circle of public center of circle B.

3. a kind of passive detection device for the full tensor information of measurement space magnetic field gradient as claimed in claim 1, it is characterized in that: in each probe unit, three pcb boards all adopt mutually orthogonal mode to be connected, offer the via hole that runs through the pcb board two sides at two mutual quadrature pcb board junction coils on complete pcb board, on the pcb board disconnected at the junction coil by the method, the two ends connecting lead wire of coil is connected by corresponding via hole, guarantees thus the coil integrity degree on each pcb board.

4. a kind of passive detection device for the full tensor information of measurement space magnetic field gradient as claimed in claim 3, it is characterized in that: described connecting lead wire adopts enameled wire.

5. a kind of passive detection device for the full tensor information of measurement space magnetic field gradient as claimed in claim 1, it is characterized in that: described signal passing interface is located on the perpendicular bisector of the signal output part line of coil on two symmetrical pcb boards.

6. a kind of passive detection device for the full tensor information of measurement space magnetic field gradient as claimed in claim 1 is characterized in that: be designed with slot on three pcb boards in described probe unit, the mode by splicing forms probe unit, is specially:

Make three pcb boards be respectively the first pcb board, the second pcb board and the 3rd pcb board; All take central point as round dot on three pcb boards, at plane right-angle coordinate that pcb board is set up in the plane;

Wherein, in the first pcb board, y axle negative direction both sides are symmetrical slot A and the slot B that is parallel to the y axle that have respectively; Y axle positive dirction has the slot C overlapped with the y axle; And the end of slot A, slot B and slot C connects the first pcb board edge, cut off coil; The other end all is positioned on the x axle.

In the second pcb board, y axle negative direction both sides are symmetrical slot D and the slot E that is parallel to the y axle that have respectively; Also have the slot F overlapped with the y axle in y axle negative direction; And slot D, slot E and slot F mono-end connect the second pcb board edge, cut off coil, the other end all is positioned on the x axle.

In the 3rd pcb board, in the 3rd pcb board center, have the axle with x, the slot G that the y axle overlaps respectively and slot H, form the cross slot; Positive negative direction at the x axle has slot I, the slot J overlapped with the x axle; Positive negative direction at the y axle has slot K, the slot L overlapped with the y axle; And slot I, slot J, slot K and slot L mono-end connect the 3rd pcb board edge, cut off coil; And slot I equates to the distance of y axle with slot A, slot B in the first pcb board with the distance of the slot J other end to the y axle; The other end of slot K and slot L to the distance of x axle with slot D, slot E in the second pcb board to the y wheelbase from equating; And the length of slot G equates with slot B spacing with slot A in the first pcb board; The length of slot H with slot D in the second pcb board, with slot E spacing, equate.

During interpolation, by three parts being separated by slot A and slot B in the first pcb board, slot I, slot G in respectively corresponding the 3rd pcb board insert and splice with slot J; By three parts of being separated by slot D and slot E in the second pcb board, slot K, slot H, slot L in respectively corresponding the 3rd pcb board insert splicing subsequently, and the slot C insertion in corresponding the first pcb board of slot F is spliced, and finally form whole probe unit.

7. as a kind of passive detection device for the full tensor information of measurement space magnetic field gradient as described in claim 1 or 6, it is characterized in that: described main body probe portion adopts Inserting structure, is specially: the 3rd pcb board in the unit A of main body probe portion layout structure, unit B, unit C, cells D, unit E is designed to the main plate of coplanar integrative-structure; Groove G two ends on the 3rd pcb board in unit A are communicated with groove J and groove I on the 3rd pcb board in unit B and unit C respectively simultaneously; Groove H two ends are communicated with groove L with the groove K on the 3rd pcb board in cells D and unit E respectively.The second pcb board in unit A, unit B, unit F and the first pcb board in unit C are designed to the horizontal plate of coplanar integrative-structure.The second pcb board in the first pcb board in unit A, unit B and unit A, unit F is designed to vertical plate of coplanar integrative-structure; Thus horizontal plate is inserted on main plate in slot transversely by horizontal plate one side coupling; Vertical plate is inserted on main plate longitudinally in slot by horizontal plate opposite side coupling; In seven probe units, all the other plates carry out interpolation according to the interpolation between three pcb boards in probe unit.

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