450 results about "Helmholtz coil" patented technology

Provided is a highly accurate optical pumping magnetometer, in which a static magnetic field and an oscillating field to be applied to a vapor cell are stabilized. To this end, the optical pumping magnetometer includes: Helmholtz coils for applying a constant static magnetic field to a vapor cell serving as a magnetic field detector; fluxgate magnetometers for detecting environmental magnetic noise in two directions of X-axis direction and Y-axis direction other than Z-axis direction which is a direction for detecting a magnetic field coming out of a measurement object while locating the vapor cell in the center thereof; magnetometer drive circuits for driving the fluxgate magneotometers; current converters for converting outputs of the magnetometer drive circuits into amount of currents; and magnetic field generating coils for generating a magnetic field in a phase opposite to the environmental magnetic noise in the two directions.

A chip scale atomic clock is disclosed that provides a low power atomic time / frequency reference that employs direct RF-interrogation on an end-state transition. The atomic time / frequency reference includes an alkali vapor cell containing alkali atoms, preferably cesium atoms, flex circuits for physically supporting, heating, and thermally isolating the alkali vapor cell, a laser source for pumping alkali atoms within the alkali vapor cell into an end resonance state by applying an optical signal along a first axis, a photodetector for detecting a second optical signal emanating from the alkali vapor cell along the first axis, a pair of RF excitation coils for applying an RF-interrogation signal to the alkali atoms along a second axis perpendicular to the first axis, a pair of bias coils for applying a uniform DC magnetic field along the first axis, and a pair of Zeeman coils for applying a Zeeman interrogation signal to the alkali atoms and oriented and configured to apply a time-varying magnetic field along the second axis through the alkali vapor cell. Another flex circuit is used for physically supporting the laser source, for heating the laser source, and for providing thermal isolation of the laser source. The laser source can be a vertical cavity surface emitting laser (VSCEL). The bias coils can be Helmholtz coils.

Provided is a highly accurate optical pumping magnetometer, in which a static magnetic field and an oscillating field to be applied to a vapor cell are stabilized. To this end, the optical pumping magnetometer includes: Helmholtz coils for applying a constant static magnetic field to a vapor cell serving as a magnetic field detector; fluxgate magnetometers for detecting environmental magnetic noise in two directions of X-axis direction and Y-axis direction other than Z-axis direction which is a direction for detecting a magnetic field coming out of a measurement object while locating the vapor cell in the center thereof; magnetometer drive circuits for driving the fluxgate magneotometers; current converters for converting outputs of the magnetometer drive circuits into amount of currents; and magnetic field generating coils for generating a magnetic field in a phase opposite to the environmental magnetic noise in the two directions.

An analytical device for rapid, non-invasive nuclear magnetic resonance (NMR) spectroscopy of multiple samples using a single spectrometer is provided. A modified toroid cavity / coil detector (TCD), and methods for conducting the simultaneous acquisition of NMR data for multiple samples including a protocol for testing NMR multi-detectors are provided. One embodiment includes a plurality of LC resonant circuits including spatially separated toroid coil inductors, each toroid coil inductor enveloping its corresponding sample volume, and tuned to resonate at a predefined frequency using a variable capacitor. The toroid coil is formed into a loop, where both ends of the toroid coil are brought into coincidence. Another embodiment includes multiple micro Helmholtz coils arranged on a circular perimeter concentric with a central conductor of the toroid cavity.

The invention pertains to the technical field of medical engineering and discloses a method for driving and controlling a universally rotating magnetic field of a medical micro-robot in a human body. The method is characterized in that three groups of Helmholtz coils on z, y and x axes are arranged by orthogonal nesting so as to ensure that respective combined inductance is equal and the amplitude of intensity of magnetization of a harmonic magnetic field generated respectively is equal when the three groups of coils are driven by the same harmonic current. The relevant amplitude of an axis azimuth angle of the robot and a same frequency sine harmonic driving current of a phase are overlapped to form a spatial universally and evenly revolving magnetic field corresponding to the revolving axis of the azimuth angle in a certain space surrounded by the orthogonal Helmholtz coils on the three axes. The self-rotating direction of the universally rotating magnetic field can be changed by changing the current frequency to adjust the revolution of the magnetic field and changing the orthogonal Helmholtz coils on the three axes to drive the current direction. The method of the invention has the beneficial effects that the method is applicable to a bending inner environment of the human body and can realize a plurality of functions of rotation, going forward and backward and speed adjusting, etc., of the robot in the human body, and the positioning operation in the human body.

A RF receive coil system for imaging a breast on a human chest with a horizontal field MRI system includes a volume saddle coil adapted to be contoured about the chest; and a Helmholtz coil having a lower portion adapted to be contoured about the chest and an upper portion adapted to be above the chest The coils are operable in quadrature mode.

The invention relates to a magnetic-field dynamic compensation system and methods based on spatial correlation, wherein the system can realize the dynamic compensation of environment magnetic fields at the directions of three axles through a large set and a small set of Helmholtz coil racks and two fluxgate meters based on the spatial correlation of a PID (Proportion Integration Differentiation) negative feedback electronic circuit and the fluctuation of the environment magnetic fields. The invention further discloses three methods using the system, including (1) a proportioning type magnetic-field dynamic compensation method, (2) a series type integral magnetic-field dynamic compensation method, and (3) a parallel integral type magnetic-field dynamic compensation method. The system of the invention is easy to construct, has low cost and simple operation, and can achieve excellent dynamic compensation effect, and simultaneously, the methods can maximally eliminate the affects of the fluxgate meters to other magnetic detectors at the centers of coils, and have great application prospect in extremely-low field nuclear magnetic resonance, imaging thereof and other biological magnetic researches based on an SQUID (Superconducting Quantum Interference Device).

The invention discloses a high-sensitivity all-optical cesium atom magnetometer and belongs to an atom magnetometer. The magnetometer is provided with a magnetic shielding tube, a Cs atom gas chamber is placed in the magnetic shielding tube, a three-axis Helmholtz coil is placed around the Cs atom air chamber, and a pump light opening, a detection light opening and am emergent light opening are respectively formed in the magnetic shielding tube. The Cs atom gas chamber is cuboid, four surfaces, used for passing through deflection light to form reflection, excepting incident light and emergent light local parts of the detection light, the Cs atom air chamber are plated with polarization-maintaining films, and the other two surfaces used for passing through pump light are not plated with films. The detection light emitted by a detection light laser enters the Cs atom gas chamber through a polarizing film and a small aperture diaphragm and is emergent after reflected on all the surfaces of the gas chamber repeatedly, the polarization plane of the emergent light rotates by a one-degree angle, one drip of Cs, 100Torr of He gas and 20Torr of N2 gas are put into the Cs atom gas chamber, and the Cs atom gas chamber works at normal temperature. The high-sensitivity all-optical cesium atom magnetometer has the advantages of being simple in structure and still capable of keeping high sensitivity without being heated.

The invention belongs to the technical field of optical pump magnetometers and discloses an atom magnetic sensor for an optical pump magnetometer. The atom magnetic sensor comprises a first half wave plate (1), a third half wave plate (5), a fourth half wave plate (8), a fifth half wave plate (9), a first polarization beam splitter prism (2), a third polarization beam splitter prism (6), a fourth polarization beam splitter prism (10), a fifth polarization beam splitter prism (7), a sixth polarization beam splitter prism (11), a first one-quarter wave plate (12), a second one-quarter wave plate (13), a first atom air chamber (14), a second atom air chamber (15), a first Helmholtz coil (16), a second Helmholtz coil (17), a first photoelectric detector (18) and a second photoelectric detector (19). By the adoption of the atom magnetic sensor, magnetic field measurement result errors caused by optical frequency shift in the laser optical pump atom magnetometer can be eliminated, and the performance index of the laser optical pump atom magnetometer can be improved.

The invention belongs to the technical field of automation engineering and discloses a method for controlling the direction of a rotation axis and the rotation direction of a space universal superposition rotating magnetic field. Three z-axis, y-axis and x-axis square Helmholtz coil groups are orthogonally nested, so that when the three groups of coils are driven by direct currents with the same current strength, the magnetic inductions generated at the center points of the three groups of coils have the same strength; the superposition rotating magnetic field is driven by an amplitude and phase compensation voltage signal through digitization so as to eliminate the influence of current lagging and inductive reactance on the current amplitude; and a same-frequency three-phase sinusoidal signal with the amplitude and the phase related to the axis azimuthal angle of a robot is used for driving to form the space universal uniform rotating magnetic field with the corresponding azimuthal rotating axis in a superimposed mode in a certain space surrounded by the three-axis orthogonal Helmholtz coil devices. According to the invention, by implementing the random regulation of the direction of the rotation axis and the rotation direction of the space universal rotating magnetic field, various operations of turning, moving forward, moving backward and the like of the micro robot in the bent or branch cavity environment are further implemented; and the method has wide application prospect.

The invention relates to a longitudinal magnetic field modulation based three-axis vector atom magnetometer and use method thereof and belongs to the technical field of low-intensity magnetic field detection. The longitudinal magnetic field modulation based three-axis vector atom magnetometer comprises a pumping optical path composed of a No.1 895nm DFB semiconductor laser, a No.1 convex lens, a No.2 convex lens, a No. 1 linear polarizing film and a Gamma / 4 slide; a detection optical path composed of a No.2 895nm DFB semiconductor laser, a No.3 convex lens, a No.4 convex lens, a No. 2 linear polarizing film, a Wollaston prism and a balance detector; a three-dimensional magnetic field generating device composed of a No.1 Helmholtz coils, a No.2 Helmholtz coils and a No.3 Helmholtz coils in mutual orthogonality; a heating device; an atomic gas cell; a locking amplifier; and a signal processing system. According to the invention, since longitudinal magnetic field modulation is adopted, technical noise can be reduced in a comparatively large degree. Therefore, extremely high flexibility is achieved. Besides, by utilizing longitudinal magnetic field modulation, inter-axis crosstalk can be reduced, so that magnetic field direction detection becomes more accurate.

The invention belongs to the technical field of optical pump magnetometers and discloses an atom magnetic sensor for an optical pump magnetometer. The atom magnetic sensor comprises a first half wave plate (1), a first polarization beam splitter prism (2), a third half wave plate (5), a third polarization beam splitter prism (6), a one-quarter wave plate (7), a Helmholtz coil (16), an atom air chamber (9), a reflector (10), a prism (11) and a photoelectric detector (12). By the adoption of the atom magnetic sensor, magnetic field measurement result errors caused by optical frequency shift in the laser optical pump atom magnetometer can be eliminated, and the performance index of the laser optical pump atom magnetometer can be improved.

The invention discloses a foldable dual-beam magnetic light trap system which is mainly suitable for generating cold atoms in laser cooling. Three pairs of laser with opposite polarization and opposite travelling are formed in a vacuum chamber through reflecting incoming laser many times, and a magnetic light trap is formed under the mutual action of a magnetic field generated by an opposite Helmholtz coil. The foldable dual-beam magnetic light trap system is characterized in that multiple reflections are utilized, and laser energy is repeatedly utilized, thereby obtaining the cold atoms. Theinvention has the advantages of simple structure, easy power balance, stable atomicgroup, low input power of laser and easy adjustment, thereby providing a better cold atom resource for cold atom frequency scale, precise measurement and laser cooling physical test.

The invention discloses a two-dimensional magnetic optical trap system and a narrow line width single photon source preparing method thereof. The system comprises two pairs of reversed Helmholtz coils, a quartz vacuum cavity, an ion pump, a current feed through part with alkali metal releasing agent, a vacuum valve, a six-way connector, a first glass window, a second glass window and a first semiconductor laser. Six openings of the six-way connector are respectively connected with the quartz vacuum cavity, the ion pump, the current feed through part, the vacuum valve, the first glass window and the second glass window. The two pairs of reversed Helmholtz coils are respectively arranged in a horizontal-symmetrical mode and in a vertical-symmetrical mode. According to the method, the two-dimensional magnetic optical trap system obtains a long-strip-shaped cold atomic group through cooling light, then spontaneous radiation four-wave mixing is used, Stokes photons and reversed Stokes photons are generated through pump light and coupling light, and the photons are collected. The line width of a narrow line width single photon source prepared by the two-dimensional magnetic optical trap system is in the megahertz magnitude, and the narrow line width single photon source is suitable for long-distance quantum communication.

A chip scale atomic clock is disclosed that provides a low power atomic time / frequency reference that employs direct RF-interrogation on an end-state transition. The atomic time / frequency reference includes an alkali vapor cell containing alkali atoms, preferably cesium atoms, flex circuits for physically supporting, heating, and thermally isolating the alkali vapor cell, a laser source for pumping alkali atoms within the alkali vapor cell into an end resonance state by applying an optical signal along a first axis, a photodetector for detecting a second optical signal emanating from the alkali vapor cell along the first axis, a pair of RF excitation coils for applying an RF-interrogation signal to the alkali atoms along a second axis perpendicular to the first axis, a pair of bias coils for applying a uniform DC magnetic field along the first axis, and a pair of Zeeman coils for applying a Zeeman interrogation signal to the alkali atoms and oriented and configured to apply a time-varying magnetic field along the second axis through the alkali vapor cell. Another flex circuit is used for physically supporting the laser source, for heating the laser source, and for providing thermal isolation of the laser source. The laser source can be a vertical cavity surface emitting laser (VSCEL). The bias coils can be Helmholtz coils.

The present invention provides a space rotating magnetic field generating device of random rotating axle, the coil part (2) is three groups pairwise orthogonal Helmholtz coils, every group coil is made up of three groups winding Helmholtz coils, and three groups coil connect each phase of three-phase current respectively. According to parameter of rotating magnetic field (1) required by user, rotating axle direction angle Theta, Phi determines initial position of rotating magnetic field Gamma, angular frequency of rotating magnetic field Omega and amplitude of rotating magnetic field B0, CPU (311) obtains variation magnetic field produced by three groups coils: BX,BYand BZ, and obtains impulse width and frequency of corresponding modulating signal, three groups waveform generators (312) of control power source part (3) inversion produce three groups three-phase current, supply for three groups coils, and produces three direction variation magnetic field. The required rotating magnetic field (1) is obtained after the three variation magnetic fields are overlapped in space. Impulse width and frequency of every waveform generator (312) modulating signal can be adjusted for changing rotating axle of rotating magnetic field, amplitude, frequency and initial position.

The invention relates to a two-dimensional magnetic-optical trap system, which belongs to the field of neutral cold atom generation technology, and is characterized in that saddle-type reversed Helmholtz coils are adopted for forming the magnetic-optical trap system. The device is compact in integral mechanical structure and easy for miniatured and engineering application; by utilizing the inherent characteristics, such as compact structure, low installing precision requirement and better radial magnetic field gradient uniformity, of the saddle-type reversed Helmholtz coils, electricity power consumption required for forming a magnetic-optical trap is reduced; through controlling atom steam pressure intensity by electrified current, continuous cold atom sources with low speed, high throughput and small divergence angle are obtained, and a better engineering application platform is provided for an atomic frequency standard, an atom interference gyroscope or other cold atom physical experiments.

The invention discloses a nuclear magnetic resonance (NMR) device based on a laser atomic magnetometer, and the NMR device comprises a cesium atom vapor bubble, a magnetic shielding bushing which is sleeved on the cesium atom vapor bubble, three groups of Helmholtz coils which are arranged inside the magnetic shielding bushing, a polarization device which is used for polarizing cesium atoms inside the cesium atom vapor bubble, a laser transmitting device which is used for transmitting detection laser to the cesium atom vapor bubble, a detection device which is used for detecting an NMR signal of the detection laser penetrating the cesium atom vapor bubble and a pneumatic sample feeding device which is used for pre-polarizing a sample to be detected and can place the pre-polarized sample on the cesium atom vapor bubble. The invention also discloses a measurement method of an NMR based on the laser atomic magnetometer. The device and the method are high in detection sensitivity, free from needing low-temperature refrigeration, low in running cost and lower in working temperature.

The invention relates to wastewater treatment method and device, in particular to a magnetic-stability fluidized bed photocatalytic reactor and a method for treating organic wastewater with difficult degradation thereby. The method solves the problems of low photocatalytic quantum, low activity and easy loss of active components existing in the traditional photocatalytic method and comprises the following steps of: feeding the organic wastewater to a reactor through a pump and a liquid inlet, adding a magnetism-loaded photocatalyst to the reactor through a catalyst feeding port, starting a fan to make air pass through a flow buffer and then enter an air distributor and make the magnetism-loaded photocatalyst be in a suspension state; starting Helmholtz coils to generate a magnetic field, opening an ultraviolet lamp when the magnetism-loaded photocatalyst is in the suspension state to degrade the organic wastewater, and then discharging the treated organic wastewater to a second liquid storage tank. The utilization rate of light energy can be improved, and because the magnetism-loaded photocatalyst is in the stable suspension state, the active component loss caused by mutual friction can be reduced; and the device has the advantages of compact structure, mild condition and high utilization rate of the light energy and can operate intermittently and run continuously.

The invention discloses a refrigerator with an electromagnetic field assisted fresh keeping property. The refrigerator comprises a refrigeration system and a magnetic field treatment system, wherein the refrigeration system comprises a compressor, an oil separator, a condenser, a liquid storage tank, a dry filter, a liquid observation mirror, an electromagnetic valve, a first capillary tube, a second capillary tube, a first evaporator, a second evaporator, a check valve, a pressure reducing valve and a gas-liquid separator; the magnetic field treatment system comprises helmholtz coils, an adjustable stabilized voltage supply, a refrigeration chamber and a freezing chamber; the first evaporator is arranged inside the refrigeration chamber; the second evaporator is arranged inside the freezing chamber; the central zones of the helmholtz coils can generate magnetic fields; and the adjustable stabilized voltage supply is used for adjusting the magnetic field frequency, electromagnetic treatment time and magnetic field intensity. According to the refrigerator, the temperature and humidity control of a food storage environment can be achieved, the magnetic field intensity in a storage chamber can be regulated as well, a biological electromagnetic effect of sterilization, quick freezing facilitation and free radical removal is generated, and the effect of improving the food fresh keeping quality is improved.

The invention belongs to the technical field of automatic engineering, and discloses a man-machine interaction control method for a space universal rotating magnetic field. Man-machine interaction control of the direction of the rotating axis of the space universal magnetic field is achieved by applying a same-frequency sinusoidal signal current type space universal rotating magnetic field superposition formula with side sway and pitch angles of the axis of the magnetic field in a longitude and latitude coordinate system as related amplitude values and phases of input variables to a three-axis orthogonal nested Helmholtz coil device, controlling the side sway and pitch angles in a separated mode through two control rods respectively, forming the rotating magnetic field with the axis capable of being independently scanned in the directions of the side sway and pitch angles in the uniform area surrounded by the three-axis orthogonal nested Helmholtz coil device in an overlapped mode, and regulating the side sway and pitch angles of the axis of the magnetic field according to wirelessly-transmitted images of a camera at the front end of a capsule robot. Independent scanning of the robot in the two directions of side sway and pitch is achieved, the man-machine interaction operation is simple and rapid, and posture adjustment and rolling operability of the robot in the bent environment is improved.

A permanent-magnet micro-robot consists of a casing (5), an axially magnetized permanent magnet (1), a radially magnetized permanent magnet (2), a non-magnetic miniature bearing (3) and a propeller (4), wherein, the head of the casing (5) is round and smooth, and a bottom (6) has a cavity (7) which is filled with lubricating grease; the axially magnetized permanent magnet (1) and the radially magnetized permanent magnet (2) are connected by the non-magnetic miniature bearing (3); the radially magnetized permanent magnet (2) and the propeller (4) are fixed via an axle (8) of the propeller. An outside magnetic field is generated by a rotation magnetic field device and a uniform magnetic field device, wherein, the rotation magnetic field consists of three groups of perpendicular Helmholtz coils, a sinusoidal current source and a phaser; the uniform magnetic field device consists of three groups of perpendicular Helmholtz coils and three groups of direct current sources. Under the effect of the rotation magnetic field, the robot rotates with the radially magnetized permanent magnet (2) and produces the axial driving force to drive; at the same time, under the deflecting guidance of the uniform magnetic field, the robot realizes flexible steering and moves along an expected locus.

The present invention discloses a coherent microwave-radiation cold atomic clock; and an ion pump is connected with a vacuum catheter which is connected with a microwave cavity; a light window is fixed in the microwave cavity by quartz glass and three reflective mirrors; a pair of anti-Helmholtz coils and a pair of Helmholtz coils are fixed on the microwave cavity; a pair of rectangular coils are fixed on the microwave cavity; a magnetic shielding system is connected with a vacuum system; semiconductor laser provides captive light and beams of pump-back light; a semiconductor laser on the vertical cavity surface provides a plurality of beams of captive light; a voltage-controlled crystal oscillator is connected with a frequency synthesizers connected with a signal receiver and processor; the semiconductor laser on the vertical cavity surface is connected with the microwave cavity; a photoelectric detector and a microwave-power receiver are connected with the signal receiver and processor connected with the voltage-controlled crystal oscillator as well as the semiconductor laser on the vertical cavity surface. The present invention is characterized in that the structure is compact and the size is small, and has good stability, high accuracy as well as good applicability.

An inspection apparatus capable of facilitating reduction in cost of the apparatus is provided. The inspection apparatus includes: beam generation means for generating any of charged particles and electromagnetic waves as a beam; a primary optical system that guides the beam into an inspection object held on a movable stage in a working chamber and irradiates the inspection object with the beam; a secondary optical system that detects secondary charged particles occurring from the inspection object; and an image processing system that forms an image on the basis of the detected secondary charged particles. The inspection apparatus further includes: a linear motor that drives the movable stage; and a Helmholtz coil that causes a magnetic field for canceling a magnetic field caused by the linear motor when the movable stage is driven.

The invention relates to an active magnetic field calibration method for a measurement while drilling (MWD) directional probe. According to the method, an MWD directional probe active magnetic field calibration instrument is used for calibration, and a high-accuracy fluxgate sensor and an MWD directional probe are arranged on a three-axis non-magnetic calibration rotation table; a computer controls a current module to produce current with certain power, a three-axis square Helmholtz coil is driven to produce a uniform magnetic field in a certain range in a central area to offset an earth magnetic field, and a non-magnetic space is formed in a certain range; the fluxgate sensor and the MWD directional probe detect signals, a data acquisition module acquires the signals, and the signals are transmitted to the computer; and calibration software on the computer are used for calculation and comparison to calibrate whether the current MWD directional probe has the qualification that the MWD can descend into the well to work normally. The method has the advantages of quickness, accuracy and stability.

This invention belongs to the technical field of the medical engineering, disclosing a basic method for applying a direct current superposed magnetic field, an azimuth of which can be adjusted, to an Helmholtz coil device of triaxial orthogonal nesting and achieves an attitude orientation in the body by combination of embedding the medical micro-robot in which embedded radial magnetized NdFeB magnet is screwed-in in a screwing mode into a wireless visual transmission system in the body and a magnetic testing. The invention is characterized in that a small magnetic needle is observed to turn superposition with the axis of the medical micro-robot in the external field by embedding the medical micro-robot into a wireless visual system, transfers the detection problem of a complex attitude azimuth into a known variable in which the azimuth of external direct current magnetic field can be readout directly. The invention has the beneficial effects of avoiding that a plurality of sensors are needed in detection and a complex computational process in the traditional method, detecting the attitude azimuth of the medical micro-robot in the body quickly by a non-contact mode, providing a position parameter for the revolving magnetic field which produces the corresponding azimuth, and improving the operability of the medical micro-robot in the bend environment.

The invention relates to a wide-dynamic-range high-temperature superconducting magnetometer comprising a superconducting quantum probe, a liquid nitrogen Dewar flask, a readout circuit, a data collection system and a micro-processor, wherein the superconducting quantum probe is arranged in a Helmholtz coil, more particularly, the superconducting quantum probe is connected with the Helmholtz coil via the liquid nitrogen Dewar flask, the readout circuit, the data collection system, the micro-processor, a constant-current source gear-selecting circuit and an adjustable constant-current source; and the readout circuit is formed by connecting a signal processing circuit with the constant-current source gear-selecting circuit. By using the standard magnetic field generated by the Helmholtz coil, part of the external magnetic field to be measured can be neutralized, and the value of the residual magnetic field to be measured after neutralization can be always within the dynamic range of the high-temperature superconducting magnetometer, the actual value of the magnetic field to be measured can be obtained by adding the value of the neutralized magnetic field to the detection value of the high-temperature superconducting magnetometer, thus preventing the sensitivity and accuracy of the high-temperature superconducting magnetometer from being reduced, widening the dynamic range thereof and meeting the operation requirements thereof within various measurement environments. Above all, the high-temperature superconducting magnetometer is suitable for the geophysical exploration in field sections where the electromagnetic interference is high.

The invention discloses a field weakening direction sensor calibration method, especially a field weakening direction sensor calibration method used for the magnetic field response value equivalent to or less than that of the earth magnetic field. The realization apparatus of the method comprises a one-dimensional rotating platform with a horizontal table top, a cuboid block for containing the field weakening direction sensor; and the whole apparatus is nonmagnetic. The method comprises: determining the special position of the sensitive direction of the field weakening direction sensor in the coordinate system composed by the magnetic field and the horizontal plane and the coordinate system of the cuboid block, by the sensor output variation along with the special position variation of the field weakening direction sensor including 360-degrees rotation in horizontal direction on the one-dimensional rotating platform and the turning of integer times of the 90-degrees of the cuboid block; and determining the output characteristics of the field weakening direction sensor. The method need not magnetic shielding room or Helmholtz coil used in the conventional field weakening direction sensor calibration, can realize the high accuracy calibration to field weakening direction sensor by simple equipment.

The invention relates to a cell culture device capable of generating multiple magnetic fields. Through three groups of orthogonal Helmholtz coils and different excitation modes thereof, a single axial steady magnetic field, a single axial alternating magnetic field, a planar rotating magnetic field and a spatial rotating magnetic field can be generated. Meanwhile, through the means of digital control and the like, control on the magnetic induction density, magnetic field frequency, temperature and CO2 concentration in the device can be realized to satisfy the conditions for the cell growth and survival. The steady, alternating, planer and spatial rotating magnetic fields can be generated, and the adjustment of the field intensity, magnetic field frequency and action time is realized through computer control; the limit that the traditional device can generate a single magnetic field is compensated; and reliable equipment and method are provided for exploring the influence and response change of different magnetic fields on the survival of the tumor cell cultured in vitro, the molecule function, the intracellular signal transduction network and cytoskeleton reconstruction and for clarifying the action mechanism of each magnetic field.