Hall magnetometer calibration device and method

Abstract

The invention discloses a Hall magnetometer calibration device, which belongs to the technical field of electromagnetic measuring instrument calibration and comprises a three-dimensional geomagnetic field counteracting assembly, a standard magnetic field reproduction assembly and a magnetic axis positioning device. The three-dimensional geomagnetic field counteracting assembly comprises three groups of mutually orthogonal electrified coils and is used for generating a constant magnetic field in a spatial three-dimensional direction; the standard magnetic field reproduction assembly is located in the three-dimensional geomagnetic field offset assembly, and the magnetic axis positioning device is located in the standard magnetic field reproduction assembly and used for positioning and adjusting a probe of the Hall magnetometer. According to the invention, the influence of a geomagnetic field can be eliminated, and accurate calibration of the high-precision Hall magnetometer is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of electromagnetic measuring instrument calibration, and in particular relates to a Hall magnetometer calibration device and method. Background Art

[0002] The Hall magnetometer is an instrument that measures magnetic field strength based on the Hall effect principle. It uses the transverse voltage difference (Hall voltage) generated when the Hall element is energized in a magnetic field to calculate the alternating and constant magnetic field strengths. It has the advantages of small size, high sensitivity, and good linearity. It is widely used in industrial measurement, scientific research, navigation and positioning, medical equipment, safety monitoring and other fields.

[0003] The magnetic field measurement range of the commonly used Hall magnetometer is from 0.1μT to 10T, and the measurement accuracy can reach up to 0.01%. Due to the wide magnetic field measurement range of the Hall magnetometer, its calibration is usually carried out in different magnetic field standard devices in sections. The measurement range above 43mT usually uses a nuclear magnetic resonance magnetometer (the lower limit of the measurement range of the nuclear magnetic resonance magnetometer is 43mT) as the magnetic field standard. The nuclear magnetic resonance magnetometer and the Hall magnetometer measure the magnetic field generated by the magnetic field coil or electromagnet respectively for comparison and calibration; the measurement range below 43mT usually uses a magnetic field coil as the standard magnetic field source, and the magnetic field coil generates standard magnetic fields of different intensities for calibration.

[0004] For magnetic fields above 43mT, the background geomagnetic field with a maximum of 65μT has a relatively small impact on the calibration process. Even for a Hall magnetometer with an accuracy of 0.01%, the impact of the background geomagnetic field can be basically ignored. However, when the strength of the standard magnetic field decreases, the impact of the background geomagnetic field gradually increases. For example, when calibrating a 10mT magnetic field point, the impact of the background geomagnetic field on the standard magnetic field can reach up to 3×10-5 times. When calibrating a Hall magnetometer with an accuracy of 0.01%, the background geomagnetic field has become one of the main sources of calibration uncertainty. When the magnetic field calibration point decreases further, it is impossible to calibrate a high-precision Hall magnetometer in the geomagnetic field. At present, domestic Hall magnetometer calibration devices do not have the function of eliminating the influence of the geomagnetic field, so it is impossible to calibrate a high-precision Hall magnetometer in the section at the lower limit of the measurement range. Summary of the invention

[0005] In view of this, the present invention provides a Hall magnetometer calibration device and method, which can eliminate the influence of the earth's magnetic field and achieve accurate calibration of a high-precision Hall magnetometer.

[0006] The present invention is achieved through the following technical solutions:

[0007] A Hall magnetometer calibration device is mainly used to calibrate the probe of the Hall magnetometer. The calibration device includes: a three-dimensional geomagnetic field offset component, a standard magnetic field reproduction component and a magnetic axis positioning device;

[0008] The three-dimensional geomagnetic field compensation component includes three groups of mutually orthogonal energized coils, which are used to generate a constant magnetic field in three-dimensional space, and the three components of the constant magnetic field are equal in magnitude and opposite in direction to the geomagnetic field, so as to offset the geomagnetic field;

[0009] The standard magnetic field reproduction component is located inside the three-dimensional geomagnetic field compensation component. The standard magnetic field reproduction component includes a one-dimensional standard magnetic field coil and a power supply component. The one-dimensional standard magnetic field coil is electrically connected to the power supply component to generate a standard magnetic field required for the Hall magnetometer calibration; and the center of the standard magnetic field coincides with the center of the three-dimensional geomagnetic field compensation component;

[0010] The magnetic axis positioning device is located in the standard magnetic field reproduction component, and the probe of the Hall magnetometer is located on the magnetic axis positioning device. The magnetic axis positioning device is used to position the probe of the Hall magnetometer so that the probe is located in the standard magnetic field and the magnetic axis of the probe is parallel to the magnetic axis of the standard magnetic field.

[0011] Further, the three-dimensional geomagnetic field cancellation component includes a three-dimensional magnetic field coil, an X-axis current source, a Y-axis current source, a Z-axis current source and a magnetometer;

[0012] The three-dimensional magnetic field coils include X-axis coil I, X-axis coil II, Y-axis coil I, Y-axis coil II, Z-axis coil I and Z-axis coil II;

[0013] The X-axis coil I and the X-axis coil II are arranged side by side and parallel to the YOZ plane; the X-axis coil I and the X-axis coil II are electrically connected to the X-axis current source respectively to generate a constant magnetic field in the X direction;

[0014] The Y-axis coil I and the Y-axis coil II are arranged side by side and parallel to the XOZ plane. The Y-axis coil I and the Y-axis coil II are electrically connected to the Y-axis current source respectively to generate a constant magnetic field in the Y direction;

[0015] The Z-axis coil I and the Z-axis coil II are arranged side by side and parallel to the XOY plane; the Z-axis coil I and the Z-axis are electrically connected to the Z-axis current source respectively to generate a constant magnetic field in the Z direction;

[0016] X-axis coil I, X-axis coil II, Y-axis coil I, Y-axis coil II, Z-axis coil I and Z-axis coil II together form a rectangular space; the magnetometer is arranged at the center of the rectangular space. When the indication of the magnetometer is zero, the geomagnetic influence in the rectangular space has been eliminated.

[0017] Furthermore, the one-dimensional standard magnetic field coil includes a plurality of circular windings, and the plurality of circular windings are coaxially arranged at intervals.

[0018] Further, the power supply assembly includes a reproducing current source and a reproducing current meter;

[0019] The reproducing current meter is arranged in series between the reproducing current source and the one-dimensional standard magnetic field coil; the reproducing current source supplies power to the one-dimensional standard magnetic field coil to generate a standard magnetic field for calibration in the coil;

[0020] The reproducing ammeter can measure the current value passing through a one-dimensional standard magnetic field coil;

[0021] The reproduced standard magnetic field value can be calculated by multiplying the coil constant and current value of the one-dimensional standard magnetic field coil;

[0022] By adjusting the magnitude of the output current of the reproducing current source, the magnitude of the reproducing standard magnetic field can be adjusted.

[0023] Further, the magnetic axis positioning device includes a probe fixing tool and a posture adjustment base;

[0024] The probe fixing tool is located on the top of the direction adjustment base and is located in the standard magnetic field in the one-dimensional standard magnetic field coil. The probe fixing tool is used to fix the probe of the Hall magnetometer;

[0025] The attitude adjustment base is used to perform vertical pitch adjustment and horizontal azimuth adjustment on the probe fixing fixture, so that the magnetic axis of the probe is parallel to the magnetic axis of the standard magnetic field.

[0026] Further, the attitude adjustment base includes a pitch rotation mechanism, an azimuth rotation mechanism and a bracket;

[0027] The pitch rotation mechanism is located on the top of the azimuth rotation mechanism, and the bracket is located on the top of the pitch rotation mechanism; the probe fixing tool is located on the bracket;

[0028] The azimuth rotation structure includes a lower fixed block and an upper rotating block; the upper rotating block is located on the top of the lower fixed block and can rotate horizontally relative to the lower fixed block;

[0029] An azimuth rotation adjustment handle is provided on the side of the azimuth rotation structure, and the upper rotating block can be rotated horizontally relative to the lower fixed block by rotating the azimuth rotation adjustment handle, thereby adjusting the azimuth of the probe fixing fixture;

[0030] The pitch rotation mechanism comprises a lower rotating block and an upper pitch block; the bottom of the lower rotating block is fixedly connected to the upper rotating block of the azimuth rotating structure; the top surface of the lower rotating block is an inwardly concave arc surface; the bottom surface of the upper pitch block is an outwardly convex arc surface; the inwardly concave arc surface of the lower rotating block cooperates with the outwardly convex arc surface of the upper pitch block;

[0031] A pitch rotation adjustment handle is arranged on the side of the pitch rotation mechanism, and the upper pitch block can be moved along the arc surface by rotating the pitch rotation adjustment handle, so as to adjust the pitch of the probe fixing tooling.

[0032] Furthermore, one side surface of the lower fixing block is an arc surface I, and a scale I is provided on the arc surface I;

[0033] One side surface of the upper rotating block is an arc surface II, and a scale II is arranged on the arc surface II;

[0034] Scale Ⅰ and scale Ⅱ are opposite to each other.

[0035] Furthermore, a scale III is arranged along the upper edge of one side surface of the lower rotating block, and a scale IV is arranged along the lower edge of one side surface of the upper pitching block, and the scale III and the scale IV are opposite to each other in the upper and lower directions.

[0036] A Hall magnetometer calibration method is based on a Hall magnetometer calibration device, and the method is:

[0037] Step 1: Place the magnetometer at the center of the energized coil, change the current in the three groups of orthogonal energized coils and observe the change in the reading of the magnetometer until the reading of the magnetometer is zero, and then take out the magnetometer;

[0038] Step 2: Fix the probe of the Hall magnetometer on the magnetic axis positioning device so that the magnetic axis direction of the probe is substantially parallel to the magnetic axis direction of the one-dimensional standard magnetic field coil;

[0039] Step 3: Use the power supply assembly to energize the one-dimensional standard magnetic field coil, and calculate and reproduce the standard magnetic field according to the energized current and the coil constant of the one-dimensional standard magnetic field coil;

[0040] Step 4: Rotate the azimuth adjustment handle to adjust the magnetic axis azimuth of the probe, and rotate the pitch adjustment handle to adjust the magnetic axis pitch of the probe. When the probe of the Hall magnetometer measures the maximum value, it can be considered that the magnetic axis direction of the probe is exactly parallel to the magnetic axis direction of the one-dimensional standard magnetic field coil, and then the Hall magnetometer is calibrated.

[0041] Beneficial effects:

[0042] (1) The present invention provides a Hall magnetometer calibration device, which first uses a three-dimensional geomagnetic field cancellation component to cancel the geomagnetic field, and then uses a standard magnetic field reproduction component to establish an accurate standard magnetic field, which can eliminate the influence of the geomagnetic field and achieve accurate calibration of a high-precision Hall magnetometer.

[0043] (2) The standard magnetic field reproducing component provided by the present invention can adjust the magnitude of the reproduced standard magnetic field by adjusting the magnitude of the output current of the reproducing current source, thereby calibrating the indication error of the Hall magnetometer under different magnetic fields.

[0044] (3) The magnetic axis positioning device provided by the present invention can accurately adjust the pitch and azimuth of the magnetic axis of the probe, so that the magnetic axis of the probe and the magnetic axis of the one-dimensional standard magnetic field coil can be precisely parallel, further improving the accuracy of the Hall magnetometer calibration.

[0045] (4) In the Hall magnetometer calibration device provided by the present invention, scales are provided on both the lower fixed block and the upper rotating block, so as to facilitate intuitive and precise adjustment of the magnetic axis orientation of the probe.

[0046] (5) In the Hall magnetometer calibration device provided by the present invention, both the lower rotating block and the upper pitch block are provided with scales, which facilitates intuitive and precise adjustment of the magnetic axis pitch of the probe.

[0047] (6) The present invention provides a Hall magnetometer calibration method, which, on the one hand, eliminates the interference of the geomagnetic field, and on the other hand, provides a magnetic axis positioning device to accurately adjust the magnetic axis direction of the probe, thereby achieving high-precision calibration of the Hall magnetometer. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 is the overall block diagram of the calibration device of the present invention;

[0049] Figure 2 It is a structural diagram of the three-dimensional magnetic field coil of the present invention;

[0050] Figure 3 It is a structural diagram of a one-dimensional standard magnetic field coil of the present invention;

[0051] Figure 4 It is a schematic diagram of installing the Hall magnetometer probe of the present invention on the magnetic axis positioning device;

[0052] Among them, 1-three-dimensional magnetic field coil, 2-X-axis current source, 3-Y-axis current source, 4-Z-axis current source, 5-reproduction current source, 6-reproduction ammeter, 7-one-dimensional standard magnetic field coil, 8-magnetic axis positioning device, 9-probe, 11-X-axis coil I, 12-X-axis coil II, 13-Y-axis coil I, 14-Y-axis coil II, 15-Z-axis coil I, 16-Z-axis coil II, 17-winding I, 18-winding II, 19-winding III, 20-winding IV, 21-azimuth rotation mechanism, 22-pitch rotation mechanism, 23-probe fixing tooling, 24-probe sensitive area, 25-handle, 26-azimuth rotation adjustment handle, 27-pitch rotation adjustment handle. DETAILED DESCRIPTION

[0053] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0054] Embodiment 1:

[0055] This embodiment provides a Hall magnetometer calibration device, which is mainly used to calibrate the probe 9 of the Hall magnetometer. Figure 1 , the calibration device includes a three-dimensional geomagnetic field offset component, a standard magnetic field reproduction component and a magnetic axis positioning device 8;

[0056] The three-dimensional geomagnetic field compensation component includes three groups of mutually orthogonal energized coils, which are used to generate a constant magnetic field in three-dimensional space, and the three components of the constant magnetic field are equal in magnitude and opposite in direction to the geomagnetic field, so as to offset the geomagnetic field;

[0057] The standard magnetic field reproduction component is located inside the three-dimensional geomagnetic field compensation component. The standard magnetic field reproduction component includes a one-dimensional standard magnetic field coil 7 and a power supply component. The one-dimensional standard magnetic field coil 7 is electrically connected to the power supply component to generate a standard magnetic field required for the Hall magnetometer calibration; and the center of the standard magnetic field coincides with the center of the three-dimensional geomagnetic field compensation component;

[0058] The magnetic axis positioning device 8 is located in the standard magnetic field reproduction component, and the probe 9 of the Hall magnetometer is located on the magnetic axis positioning device 8. The magnetic axis positioning device 8 is used to position the probe 9 of the Hall magnetometer so that the probe 9 is located in the standard magnetic field and the magnetic axis of the probe 9 is parallel to the magnetic axis of the standard magnetic field.

[0059] The present embodiment provides a Hall magnetometer calibration device, which first uses a three-dimensional geomagnetic field cancellation component to cancel the geomagnetic field, and then uses a standard magnetic field reproduction component to establish an accurate standard magnetic field, which can eliminate the influence of the geomagnetic field and achieve accurate calibration of a high-precision Hall magnetometer.

[0060] With any point on the horizontal plane as the center of the circle, the vertical direction as the Z direction, and any direction on the horizontal plane as the X direction, a three-dimensional space coordinate system O-XYZ is established;

[0061] The three-dimensional geomagnetic field compensation component includes a three-dimensional magnetic field coil 1, an X-axis current source 2, a Y-axis current source 3, a Z-axis current source 4 and a magnetometer; the three-dimensional magnetic field coil 1 can adopt a three-axis square Helmholtz coil, a three-axis circular Helmholtz coil, a three-axis Barker coil and a three-axis Maxwell coil; the magnetometer can adopt a fluxgate magnetometer;

[0062] See attached Figure 2 In this embodiment, a three-axis square Helmholtz coil is used; see the attached Figure 2 , the three-axis square Helmholtz coil includes an X-axis coil Ⅰ11, an X-axis coil Ⅱ12, a Y-axis coil Ⅰ13, a Y-axis coil Ⅱ14, a Z-axis coil Ⅰ15 and a Z-axis coil Ⅱ16;

[0063] The X-axis coil I 11 and the X-axis coil II 12 are arranged side by side and parallel to the YOZ plane; the X-axis coil I 11 and the X-axis coil II 12 are electrically connected to the X-axis current source 2 respectively, so as to generate a constant magnetic field in the X direction;

[0064] The Y-axis coil I 13 and the Y-axis coil II 14 are arranged side by side and parallel to the XOZ plane. The Y-axis coil I 13 and the Y-axis coil II 14 are electrically connected to the Y-axis current source 3 respectively to generate a constant magnetic field in the Y direction;

[0065] The Z-axis coil I 15 and the Z-axis coil II 16 are arranged side by side and parallel to the XOY plane; the Z-axis coil I 15 and the Z axis are electrically connected to the Z-axis current source 4 respectively, for generating a constant magnetic field in the Z direction;

[0066] X-axis coil Ⅰ11, X-axis coil Ⅱ12, Y-axis coil Ⅰ13, Y-axis coil Ⅱ14, Z-axis coil Ⅰ15 and Z-axis coil Ⅱ16 together form a rectangular space; the magnetometer is set at the center of the rectangular space. When the indication of the magnetometer is zero, it can be considered that the geomagnetic influence in the rectangular space has been eliminated.

[0067] X-axis coil I 11, X-axis coil II 12, Y-axis coil I 13, Y-axis coil II 14, Z-axis coil I 15 and Z-axis coil II 16 are energized to form the aforementioned three groups of mutually orthogonal energized coils;

[0068] The one-dimensional standard magnetic field coil 7 of the standard magnetic field reproduction component can be a Barker coil, a Barker coil, a Helmholtz coil or a Maxwell coil, and the coil can be square or circular.

[0069] See attached Figure 3 In this embodiment, the one-dimensional standard magnetic field coil 7 adopts a circular Barker coil; see the attached Figure 4 The circular Barker coil includes a plurality of circular windings, which are coaxially arranged at intervals; the center of the one-dimensional standard magnetic field coil 7 coincides with the center of the three-dimensional magnetic field coil 1.

[0070] Specifically, the circular Buckel coil includes four circular windings, namely winding I 17 , winding II 18 , winding III 19 and winding IV 20 .

[0071] The power supply assembly includes a reproducing current source 5 and a reproducing ammeter 6; the reproducing ammeter 6 is arranged in series between the reproducing current source 5 and the one-dimensional standard magnetic field coil 7; the reproducing current source 5 supplies power to the one-dimensional standard magnetic field coil 7 to generate a standard magnetic field for calibration in the coil; the reproducing ammeter 6 can accurately measure the current value passing through the one-dimensional standard magnetic field coil 7, and the value of the reproduced standard magnetic field can be calculated by multiplying the coil constant of the one-dimensional standard magnetic field coil 7 and the current value. By adjusting the output current of the reproducing current source 5, the value of the reproduced standard magnetic field can be adjusted, and the indication error of the Hall magnetometer under different magnetic fields can be calibrated.

[0072] In addition, resistors and voltmeters can be used as power components.

[0073] See attached Figure 4 , the magnetic axis positioning device 8 includes a probe fixing tool 23 and a posture adjustment base;

[0074] The probe fixing fixture 23 is located on the top of the direction adjustment base and is located in the standard magnetic field of the one-dimensional standard magnetic field coil 7. A V-shaped groove is provided on the probe fixing fixture 23 for fixing the probe 9 of the Hall magnetometer;

[0075] The probe 9 of the Hall magnetometer includes a probe sensitive area 24 and a handle 25, wherein the probe sensitive area 24 is located at one end of the probe 9, and the handle 25 is located at the other end of the probe 9;

[0076] The attitude adjustment base is used to perform pitch adjustment in the vertical direction and azimuth adjustment in the horizontal direction on the probe fixing fixture 23 , so that the magnetic axis of the probe 9 is parallel to the magnetic axis of the standard magnetic field.

[0077] The attitude adjustment base includes a pitch rotation mechanism, an azimuth rotation mechanism 21 and a bracket;

[0078] The pitch rotation mechanism is located at the top of the azimuth rotation mechanism 21, and the bracket is located at the top of the pitch rotation mechanism; the probe fixing tool 23 is located on the bracket;

[0079] The azimuth rotation structure includes a lower fixed block and an upper rotating block; the upper rotating block is located on the top of the lower fixed block and can rotate horizontally relative to the lower fixed block;

[0080] An azimuth rotation adjustment handle 26 is provided on the side of the azimuth rotation structure, and the upper rotating block can be rotated horizontally relative to the lower fixed block by rotating the azimuth rotation adjustment handle 26, thereby adjusting the azimuth of the probe fixing tooling 23;

[0081] Furthermore, one side of the lower fixed block is an arc surface I, and a scale I is arranged on the arc surface I; one side of the upper rotating block is an arc surface II, and a scale II is arranged on the arc surface II; the scale I and the scale II are opposite to each other, and the rotation angle of the upper rotating block can be known by observing the scale, so that the position of the probe fixing tooling 23 can be adjusted more accurately;

[0082] The pitch rotation mechanism comprises a lower rotating block and an upper pitch block; the bottom of the lower rotating block is fixedly connected or integrally formed with the upper rotating block of the azimuth rotating structure; the top surface of the lower rotating block is an inwardly concave arc surface; the bottom surface of the upper pitch block is an outwardly convex arc surface; the inwardly concave arc surface of the lower rotating block cooperates with the outwardly convex arc surface of the upper pitch block;

[0083] A pitch rotation adjustment handle 27 is provided on the side of the pitch rotation mechanism. By rotating the pitch rotation adjustment handle 27, the upper pitch block can be moved along the arc surface, thereby adjusting the pitch of the probe fixing tooling 23;

[0084] Furthermore, a side surface of the lower rotating block is provided with a scale III along the upper edge, and a side surface of the upper pitch block is provided with a scale IV along the lower edge. Scale III and scale IV are opposite to each other in vertical direction. By observing the scales, the pitch angle of the upper pitch block can be known, so that the pitch of the probe fixing tooling 23 can be adjusted more accurately.

[0085] In a specific embodiment, the aforementioned horizontal rotation of the upper rotating block relative to the lower fixed block by rotating the azimuth rotation adjustment handle 26 and the aforementioned movement of the upper pitch block along the arc surface by rotating the pitch rotation adjustment handle 27 can both be achieved through the structure of the worm gear.

[0086] Embodiment 2:

[0087] This embodiment provides a specific embodiment based on Embodiment 1.

[0088] The X-axis coil I 11 and the X-axis coil II 12 of the three-dimensional geomagnetic field compensation assembly have the same size and parameters, both are squares with a winding side length of 600 mm, both have 16 turns of winding, and the spacing between the two is 327 mm;

[0089] The Y-axis coil I 13 and the Y-axis coil II 14 have the same size and parameters, both of which are squares with a winding side length of 550 mm, 16 winding turns, and a center distance between the two of 299.5 mm;

[0090] The size and parameters of the Z-axis coil I 15 and the Z-axis coil II 16 are the same, both are squares with a winding side length of 500 mm, the number of winding turns is 20, and the spacing between the two is 272 mm;

[0091] The coil constants of the X-axis coil Ⅰ11, the X-axis coil Ⅱ12, the Y-axis coil Ⅰ13 and the Y-axis coil Ⅱ14 are all greater than 42μT / A, and the coil constants of the Z-axis coil Ⅰ15 and the Z-axis coil Ⅱ16 are all greater than 65μT / A;

[0092] The maximum output current of X-axis current source 2, Y-axis current source 3 and Z-axis current source 4 are all 1A;

[0093] The above-mentioned three-dimensional geomagnetic field compensation component can offset the background geomagnetic field at any position in the country, and form a zero magnetic field space in a spherical area with a diameter of 30 mm at the geometric center of the three axes of the coil.

[0094] The winding center diameters of winding I 17 and winding II 18 of the one-dimensional standard magnetic field coil 7 are both 300 mm, the number of turns is both 342 turns, and the distance between the center of winding I 17 and the center of winding II 18 is 72 mm;

[0095] The center diameters of winding III 19 and winding IV 20 are both 300 mm, the number of turns is 778 turns, and the distance between the center of winding III 19 and the center of winding IV 20 is 278 mm; the distance between winding 20 and winding 17 is equal to the distance between winding 18 and winding 19.

[0096] The total coil constant of the one-dimensional standard magnetic field coil 7 after the four windings are combined is 5mT / A, and the spherical area with a diameter of 30mm at the geometric center of the four windings is the magnetic field working area;

[0097] The current output range of the reproducing current source 5 of the power supply component is 20mA to 10A, and the measurement range of the reproducing current source 5 is 10mA to 20A;

[0098] The standard magnetic field reproduction component can reproduce the standard magnetic field in the range of 0.1mT to 50mT. The standard magnetic field can be accurately reproduced by combining the coil constant of the one-dimensional standard magnetic field coil 7 (regularly sent to the metrology agency for calibration) and the measured current value.

[0099] The length and width of the pitch rotation mechanism and azimuth rotation mechanism of the magnetic axis positioning device 8 are both 120mm, and the azimuth and pitch angles can be precisely rotated within the range of ±10°, with an adjustment resolution better than 0.01°.

[0100] The V-shaped groove of the probe fixing fixture 23 can be used to install a probe 9 with a handle diameter between 8 mm and 20 mm;

[0101] In order to avoid the influence of material magnetism on the calibration of the Hall magnetometer, the magnetic axis adjustment device 8 is made entirely of non-magnetic materials, the main structure of the magnetic axis positioning device 8 is made of 6061 aluminum alloy, and the worm gear is made of brass.

[0102] Embodiment 3:

[0103] This embodiment provides a Hall magnetometer calibration method based on Embodiment 1 or Embodiment 2, and the method is as follows:

[0104] Step 1: Place the magnetometer at the center of the energized coil, change the current in the three groups of orthogonal energized coils and observe the change in the magnetometer indication at the same time, make the magnetometer indication zero, and take out the magnetometer.

[0105] Step 2: fix the probe 9 of the Hall magnetometer on the magnetic axis positioning device 8 so that the magnetic axis direction of the probe 9 is substantially parallel to the magnetic axis direction of the one-dimensional standard magnetic field coil 7;

[0106] Step 3: energize the one-dimensional standard magnetic field coil 7 using the power supply assembly, and calculate and reproduce the standard magnetic field according to the energized current and the coil constant of the one-dimensional standard magnetic field coil 7;

[0107] Step 4: Rotate the azimuth rotation adjustment handle 26 to adjust the azimuth of the magnetic axis of the probe 9, and rotate the pitch rotation adjustment handle 27 to adjust the pitch of the magnetic axis of the probe 9. When the probe 9 of the Hall magnetometer measures the maximum value, it can be considered that the magnetic axis direction of the probe 9 is exactly parallel to the magnetic axis direction of the one-dimensional standard magnetic field coil 7, and then the Hall magnetometer is calibrated.

[0108] The Hall magnetometer calibration method provided in this embodiment eliminates the interference of the earth's magnetism on the one hand, and on the other hand, a magnetic axis positioning device 8 is provided to adjust the magnetic axis direction of the probe 9, thereby achieving high-precision calibration of the Hall magnetometer.

[0109] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A Hall magnetometer calibration device, mainly used to calibrate the probe of the Hall magnetometer, characterized in that: The calibration device includes: a three-dimensional geomagnetic field offset component, a standard magnetic field reproduction component and a magnetic axis positioning device; The three-dimensional geomagnetic field compensation component includes three groups of mutually orthogonal energized coils, which are used to generate a constant magnetic field in three-dimensional space, and the three components of the constant magnetic field are equal in magnitude and opposite in direction to the geomagnetic field, so as to offset the geomagnetic field; The standard magnetic field reproduction component is located inside the three-dimensional geomagnetic field compensation component. The standard magnetic field reproduction component includes a one-dimensional standard magnetic field coil and a power supply component. The one-dimensional standard magnetic field coil is electrically connected to the power supply component to generate a standard magnetic field required for the Hall magnetometer calibration; and the center of the standard magnetic field coincides with the center of the three-dimensional geomagnetic field compensation component; The magnetic axis positioning device is located in the standard magnetic field reproduction component, and the probe of the Hall magnetometer is located on the magnetic axis positioning device. The magnetic axis positioning device is used to position the probe of the Hall magnetometer so that the probe is located in the standard magnetic field and the magnetic axis of the probe is parallel to the magnetic axis of the standard magnetic field.

2. A Hall magnetometer calibration device as claimed in claim 1, characterized in that: The three-dimensional geomagnetic field compensation component includes a three-dimensional magnetic field coil, an X-axis current source, a Y-axis current source, a Z-axis current source and a magnetometer; The three-dimensional magnetic field coils include X-axis coil I, X-axis coil II, Y-axis coil I, Y-axis coil II, Z-axis coil I and Z-axis coil II; The X-axis coil I and the X-axis coil II are arranged side by side and parallel to the YOZ plane; the X-axis coil I and the X-axis coil II are electrically connected to the X-axis current source respectively to generate a constant magnetic field in the X direction; The Y-axis coil I and the Y-axis coil II are arranged side by side and parallel to the XOZ plane. The Y-axis coil I and the Y-axis coil II are electrically connected to the Y-axis current source respectively to generate a constant magnetic field in the Y direction; The Z-axis coil I and the Z-axis coil II are arranged side by side and parallel to the XOY plane; The Z-axis coil I and the Z-axis are electrically connected to the Z-axis current source respectively to generate a constant magnetic field in the Z direction; X-axis coil Ⅰ, X-axis coil Ⅱ, Y-axis coil Ⅰ, Y-axis coil Ⅱ, Z-axis coil Ⅰ and Z-axis coil Ⅱ together form a rectangular space; The magnetometer is set at the center of the rectangular space. When the indication of the magnetometer is zero, the geomagnetic influence in the rectangular space has been eliminated.

3. A Hall magnetometer calibration device as claimed in claim 1, characterized in that: The one-dimensional standard magnetic field coil comprises a plurality of circular windings, and the plurality of circular windings are coaxially arranged at intervals.

4. A Hall magnetometer calibration device as claimed in claim 1, characterized in that: The power supply assembly includes a reproducing current source and a reproducing current meter; The reproducing current meter is arranged in series between the reproducing current source and the one-dimensional standard magnetic field coil; the reproducing current source supplies power to the one-dimensional standard magnetic field coil to generate a standard magnetic field for calibration in the coil; The reproducing ammeter can measure the current value passing through a one-dimensional standard magnetic field coil; The reproduced standard magnetic field value can be calculated by multiplying the coil constant and current value of the one-dimensional standard magnetic field coil; By adjusting the magnitude of the output current of the reproducing current source, the magnitude of the reproducing standard magnetic field can be adjusted.

5. A Hall magnetometer calibration device as claimed in any one of claims 1 to 4, characterized in that: The magnetic axis positioning device includes a probe fixing tool and a posture adjustment base; The probe fixing tool is located on the top of the direction adjustment base and is located in the standard magnetic field in the one-dimensional standard magnetic field coil. The probe fixing tool is used to fix the probe of the Hall magnetometer; The attitude adjustment base is used to perform vertical pitch adjustment and horizontal azimuth adjustment on the probe fixing fixture, so that the magnetic axis of the probe is parallel to the magnetic axis of the standard magnetic field.

6. A Hall magnetometer calibration device as claimed in claim 5, characterized in that: The attitude adjustment base includes a pitch rotation mechanism, an azimuth rotation mechanism and a bracket; The pitch rotation mechanism is located on the top of the azimuth rotation mechanism, and the bracket is located on the top of the pitch rotation mechanism; the probe fixing tool is located on the bracket; The azimuth rotation structure includes a lower fixed block and an upper rotating block; the upper rotating block is located on the top of the lower fixed block and can rotate horizontally relative to the lower fixed block; An azimuth rotation adjustment handle is provided on the side of the azimuth rotation structure, and the upper rotating block can be rotated horizontally relative to the lower fixed block by rotating the azimuth rotation adjustment handle, thereby adjusting the azimuth of the probe fixing fixture; The pitch rotation mechanism comprises a lower rotating block and an upper pitch block; the bottom of the lower rotating block is fixedly connected to the upper rotating block of the azimuth rotating structure; the top surface of the lower rotating block is an inwardly concave arc surface; the bottom surface of the upper pitch block is an outwardly convex arc surface; the inwardly concave arc surface of the lower rotating block cooperates with the outwardly convex arc surface of the upper pitch block; A pitch rotation adjustment handle is arranged on the side of the pitch rotation mechanism, and the upper pitch block can be moved along the arc surface by rotating the pitch rotation adjustment handle, so as to adjust the pitch of the probe fixing tooling.

7. A Hall magnetometer calibration device as claimed in claim 6, characterized in that: One side surface of the lower fixed block is an arc surface I, and a scale I is arranged on the arc surface I; One side surface of the upper rotating block is an arc surface II, and a scale II is arranged on the arc surface II; Scale Ⅰ and scale Ⅱ are opposite to each other.

8. A Hall magnetometer calibration device as claimed in claim 6, characterized in that: A scale III is arranged along the upper edge of one side surface of the lower rotating block, and a scale IV is arranged along the lower edge of one side surface of the upper pitching block, and the scale III and the scale IV are opposite to each other in the upper and lower directions.

9. A Hall magnetometer calibration method, based on the Hall magnetometer calibration device according to claim 6, characterized in that: The method is: Step 1: Place the magnetometer at the center of the energized coil, change the current in the three groups of orthogonal energized coils and observe the change in the reading of the magnetometer until the reading of the magnetometer is zero, and then take out the magnetometer; Step 2: Fix the probe of the Hall magnetometer on the magnetic axis positioning device so that the magnetic axis direction of the probe is substantially parallel to the magnetic axis direction of the one-dimensional standard magnetic field coil; Step 3: Use the power supply assembly to energize the one-dimensional standard magnetic field coil, and calculate and reproduce the standard magnetic field according to the energized current and the coil constant of the one-dimensional standard magnetic field coil; Step 4: Rotate the azimuth adjustment handle to adjust the magnetic axis azimuth of the probe, and rotate the pitch adjustment handle to adjust the magnetic axis pitch of the probe. When the probe of the Hall magnetometer measures the maximum value, it can be considered that the magnetic axis direction of the probe is exactly parallel to the magnetic axis direction of the one-dimensional standard magnetic field coil, and then the Hall magnetometer is calibrated.

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