SU920590A1 - Device for registering magnetic fields of dispersion - Google Patents

Description

(54) DEVICE FOR REGISTRATION OF MAGNETIC FIELDS AND SCATTERING

The invention relates to magnetometry and can be used to record the magnetic fields of jpatcene. :

A device for recording magnetic fields is known, comprising an excitation generator, a magneto-sensitive element, an amplifier, a recorder, a reference signal modeling unit 1.

A disadvantage of the known device is low sensitivity:. to weak magnetic fields (due to the high sensitivity threshold).

The aim of the invention is poV (Improving sensitivity.

The goal is achieved by the fact that a device for detecting magnetic fields of a scattering, containing a series-connected magnetically sensitive element, an amplifier and a recorder, is provided with a tip in the form of a rigid rectangular frame, in which the magnetosensitive element is fixed, and two ferromagnetic plates, which are fixed using micro-screws to the corresponding poles of the tip.

FIG. 1 shows the device, a general view; FIG. 2 shows the dependence of the normal component of the field on the position of the magnetically sensitive element (ferrosonde) relative to the scattering field formed by na3OMi on

10 of FIG. 3 - the position of the rectangular plates relative to the groove.

The device includes a magnetically sensitive element 1, fixed in the tip 2, made in the form of a rigid rectangular frame, in the lower part of which plates of ferromagnetic material are fixed with the help of ikro screws 3, in section

Claims (1)

20 which are rectangles with height h 2.4 mm and width L 10 mm. The plates are made of ferromagnetic material with high magnetic permeability, and their shape and geometrical dimensions are chosen according to the specific conditions of distribution of the magnetic scattering fields. Such a design is a kind of co-centering of the existing magnetic π l scattering band, due to which the sensitivity threshold is lowered and consequently the sensitivity increases. The tip is placed above the ferromagnetic object 5 with a defect (groove 6) under study. A magnetically sensitive element is successively connected with an amplifier 7 and a recorder 8. The device operates as follows; The tip 2 of the magneto-sensing device 1 has a groove 6 above the real element of the follow zone, in which the presence of a weak magnetic field is assumed. The magnetically sensitive element (ferrozond) 1, fixed in tip 2, is placed above the plates k and using microscrews 3. move the plates k and receive on the recorder 8 the maximum signal passing through the amplifier 7- The magnitude of the received signal is judged by the magnitude of the magnetic field neither In this case, the sensitivity is increased due to a kind of concentration of the magnetic field of the ferromagnetic plates k made of a magnetically strong material with a high magnetic permeability, and the degree of concentration of magnetic field lines in the plates 4 depends on the location of the plates relative to each other, a magnetically sensitive element 1, the source of the magnetic field of the diffuser 6, as well as the shape and geometrical dimensions of these plates, which are chosen based on the shape of the intended magnet deleterious scattering floor (in relation to the groove selected rectangular plate shape). FIG. Figure 2 shows the increase in the normal component of the magnetic field HUB as a function of the defect coordinate. A ferromagnetic image is produced with a groove 6 (imitate a crack) with residual magnetization. The dependence of the normal component of the magnetic field on the horizontal coordinate X is measured (Fig. 2, curve 1). Then at a height of h 2 ,. mm above the surface of the sample, the dependence of the normal component of the magnetic field on the x coordinate without plates k (curve 2) and plates 4 (curve 3) is measured. From the analysis of the dependences obtained, one can clearly see an increase in the maximum value of the normal component of the floor when using plates 4 not only in comparison with the normal component of the floor measured at the same height from the groove (Fig. 2, curve 2), but also in comparison with the maximum of the normal field, measured directly on the surface of the object under investigation (Fig. 2, curve 1). From here you can clearly see the possibility of increasing the sensitivity when using the tip, made in the form of a hard frame rectangle, in the bottom th part which via microscrews two ferromagnetic plates are fixed, the geometry and location of which are selected based on the specific conditions of the distribution of magnetic fields scattering. The use of this device allows one to significantly increase the sensitivity due to the concentration of the magnetic field scattered in the area of the magnetically sensitive element, and also allows one to avoid unwanted frequent contact of the magnetically sensitive element with the object of study. Claims An apparatus for detecting magnetic fields of a scattering, containing a series-connected magnetically sensitive element, an amplifier and a recorder, characterized in that, in order to increase the sensitivity, it is provided with a tip in the form of a rigid rectangular frame in which the magnetic sensitive element is fixed, and ferromagnetic plates that are attached with microscrews to the respective poles of the tip. . Sources of information taken into account in the examination. 1. USSR author's certificate No. 678438, cl. G .01 R 33/02, 1977