31 results about "Barkhausen effect" patented technology

The present invention provides a defect and stress non-destructive testing system and non-destructive testing method based on pulsed eddy current and Barkhausen, and belongs to the field of non-destructive testing. According to the present invention, the system comprises an excitation signal generator, a digital-to-analog converter, a power amplifier, an excitation coil, a Hall sensor, a signal amplification circuit, a data acquisition card and a computer; on the basis of eddy current testing, based on the ferromagnetic material, the mixed wave of the rectangular wave and the triangular wave is adopted as the excitation signal, the rectangular wave band at the first half section in the mixed signal produces the pulsed eddy current phenomenon, the triangular wave band at the later half section in the mixed wave produces the barkhausen effect, the sectional treatment is performed on the signal by using a signal time domain average method to achieve the separation of the eddy current signal and the Barkhausen noise signal, and the signal is respectively subjected to feature extraction and data processing so as to concurrently achieve online detection of the surface defect, the stress and the microstructure state of the ferromagnetic material and achieve the discrimination of the ferromagnetic material recessive defect, the prediction of the defect being not yet formed, and the prediction of the service life; and the method has characteristics of long-term and reliable work, high sensitivity, simpleness, intuitive display, high efficiency, feasibility, and the like.

A recording paper contains a pulp fiber and a magnetic fiber having a large Barkhausen effect. The fiber orientation ratio of this recording paper by an ultrasonic propagation velocity method is in a range of more than 1.3 to less than 1.8, and the degree of shrinkage in an MD thereof is 0.25% or less.

The invention provides a magnetic wire and a recording medium. The magnetic wire includes a magnetic metal wire material having a surface coated with a layer of an insulating material. The magnetic wire has a magnetic coercive force of 30 A/m or less and has a Barkhausen effect.

A transfer paper for electrophotography contains a pulp fiber and a magnetic material for generating a large Barkhausen effect. An average dehydration speed S 1 a (an average value (% by mass/second) of dehydration speeds S 1 of 5 sheets of paper) is 0.15 or less. The dehydration speed S 1 is represented by (W 1 a-W 1 b)/30. Here, W 1 a represents a moisture content ratio (% by mass) of the paper after moisture conditioning, and W 1 b represents a moisture content ratio (% by mass) of the paper after a dehydration process including leaving the paper in a 80 DEG C. environment for 30 seconds after moisture conditioning.

The present invention provides a security functional thin film and a security product containing such a thin film. The security functional thin film is of an amorphous structure, and possesses soft magnetic characteristics. Large Barkhausen effect can be detected along the in-plane preferred direction of magnetization; and the Large Barkhausen effect significantly attenuates, or no such signal can be detected, in a direction perpendicular to the in-plane preferred direction of magnetization. The thin film has a thickness of 20-300 nm, and the thin film also possesses element encoding characteristics that can be authenticated by experts. The security functional thin film of the present invention can be fabricated by magnetron sputtering web coating process. The security product provided by the present invention has a security information layer formed of the security functional thin film, and can be combined with other security characteristics for use in fabricating security materials such as security threads, security tapes, paper security strip-like inserts, or security labels, and others. Compared with conventional anti-counterfeiting technologies, the instant security functional thin film has more hidden security information, and facilitates enhancement of safety performance of security products.

The invention provides a micro-thrust measurement system based on the Barkhausen effect. According to characteristics of the electric propulsion thrust as well as the inverse magnetostrictive effect (magnetism principle) and the Barkhausen effect, a thruster applies the thrust to a magnetoelastic element and then the change of Barkhausen noises is measured to obtain the change of the internal stress of the magnetoelastic element, so that the magnitude and variation of the thrust are obtained. The a micro-thrust measurement system has advantages of simple structure, great convenience in operation, high reliability, and high detection sensitivity and accuracy; the change of stress is measured in real time; and the small transient thrust of the electric thruster is measured precisely.

A baggage management gate including an exciting coil, a detecting coil and signal processing unit. The exciting coil forms an alternating magnetic field in a passage to an area from which manages objects to be carried in or carried out. The detecting coil detects a variation in the alternating magnetic field when magnetization of a magnetic material showing a large Barkhausen effect is reversed in the alternating magnetic field. The signal processing unit determines as to whether the magnetization reversal occurs in the alternating magnetic field due to the large Barkhausen effect or not, based on a signal detected by the detecting coil. The signal processing unit includes amplifier that amplifies the signal detected by the detecting coil with plural different amplification factors and output the amplified signals with each of the plural different amplification factors.

The present invention relates to a memory with an anti-theft function, and a method preparing the memory with the anti-theft function. An amorphous fiber with the Great Barkhausen effect is embedded in the memory with the anti-theft function, wherein the diameter of the amorphous fiber is 10-150 micron, preferably 20-30 micron, and the length of the amorphous fiber is 2-15mm, 3-8mm, or 3-5mm.

The invention relates to antitheft safety paper and a preparation method thereof. Particularly, noncrystalline fiber with is implanted in the antitheft safety paper, and diameter of the noncrystalline fiber is 10-50 micronmeters and 20-30 micrometers preferably while length of the same is 2-10mm or 3-8mm or 3-5mm.

The invention relates to anti-theft safety paper. Non-crystal naked fibers having a big barkhausen effect are planted in the anti-theft safety paper, wherein the diameter of the non-crystal naked fibers is 10-50 microns, preferably 20-30 microns; and the length of the non-crystal naked fibers is 2-10mm, or 3-8mm, or 3-5mm.

A control gate, including an exciting coil and a detecting coil, is disclosed. The exciting coil forms an alternating magnetic field in a passageway at an entrance to or an exit from an area where taking out or bringing in of an object is controlled. The detecting coil detects a change of the magnetic field when magnetic substance contained in the object generating a large Barkhausen effect causes magnetic inversion in the alternating magnetic field. The exciting coil is provided above the passageway and has a winding wire wound along a horizontal plane. The detecting coil is provided in a side part of the passageway and has a winding wire wound along a vertical plane which is parallel to a passing direction of the passageway.

The invention relates to anti-theft safety paper and a method for preparing the anti-theft safety paper, and provides the anti-theft safety paper. Non-crystal fibers having a big barkhausen effect are planted in the anti-theft safety paper, wherein the diameter of the non-crystal fibers is 80-200 microns, preferably 100-150 microns; and the length of the non-crystal fibers is 2-10mm.

The invention discloses a Barkhausen effect-based electromagnetic suspension track magnetic characteristic detection method and device. The device comprises a packaging mould, a clamping device, an excitation probe, a detection probe and a digital signal processor, wherein the clamping device is used for putting the packaging mould below an inner groove of an F-shaped to-be-detected electromagnetic suspension track; the excitation probe is pre-packaged in the packaging mould and is used for carrying out alternating magnetization on the to-be-detected electromagnetic suspension track; the detection probe is pre-packaged in the packaging mould and is used for generating a corresponding Barkhausen signal when the alternating magnetization is carried out on the to-be-detected electromagnetic suspension track; and the digital signal processor is used for processing the Barkhausen signal to obtain corresponding signal strength so as to carry out defect analysis on the to-be-detected electromagnetic suspension track by utilizing the signal strength. According to the method and device, the electromagnetic suspension track defect detection precision can be improved, and the excitation probeand the detection probe are pre-paced in the packaging mould below the inner groove of the F-shaped to-be-detected electromagnetic suspension track, so that trains can be prevented from colliding with the packaging mould in the running process.