SU618705A1 - Method of measuring dynamic magnetic field intensity spatial distribution - Google Patents

Description

This invention relates to the measurement of the intensity of non-stationary magnetic fields. It can be used in studies in solid state physics, plasma physics, etc.

There is a method for measuring the intensity of magnetic fields by means of inductive probes such as multi-turn coils. The intensity of the magnetic field is determined by measuring the emf induced in a measuring coil located in the measurement area. The change in time of the flux of the magnetic field penetrating the coil leads to the appearance of a variable induction EMF at its ends.

This method does not provide a measurement of the spatial distribution of the intensity of a non-stationary magnetic field and long-term storage of information.

Closest to the proposed method of measuring the spatial distribution of the intensity of a non-stationary electromagnetic field using a magnetic film as a sensor, in which the film is stirred in the field of measuring the intensity of a magnetic field along the measured component field so that the measured composition of film plane. and nPeremagnetized film with a periodic magnetic field, the direction of which is perpendicularly measured and parallel to the film plane. In case of magnetic reversal of the film, the electromagnetic field is modulated. The amplitude of the magnetic component is determined by the amplitude of the video pulses produced in the detector section.

W

The disadvantage of this method is the difficulty of measuring the spatial distribution of the intensity of a non-stationary magnetic field. This method measures local stress values.

The purpose of the invention is to simplify the measurement of the continuous distribution of the Hpstness of a non-stationary magnetic field.

The goal is achieved by placing the magnetic film along

the measured component of the field, having previously recorded an audio signal on it, and the intensity distribution determined by the level of the residual signal on the magnetic film formed as a result of the interaction of the magnetic field with the film.

Unsteady magnetic booty, on film, leads to a weakening

10 level of the signal recorded on it. This attenuation depends on the intensity of the magnetic field at each point in space. On a magnetic film, the shape of the residual signal carries information about

15 the distribution of the intensity of the magnetic field due to its single effect on the magnetic film in the region of intention. The relationship between the level of residual signal on the magnetic film and the value

The 20 magnetic field strength was established by comparing the magnetic field strength value H (7i) y obtained using a calibrated induction coil (probe) and the degree

25 attenuation of an audio signal recorded on a magnetic film in those parts of its length that correspond to fixed points in the location of the probe in the measurement area:

thirty

.-i2

H "(

A (5:

AO

where A (the signal level from the magnetic film, which interacts with the magnetic field;

AO is the signal level from the magnetic film before interacting with the magnetic field;

HjcottSt, which characterizes the magnetic properties of a type of film. For 10 n film.

The resulting dependence of the attenuation of the level of the residual signal on the magnetic film on the amplitude of the magnetic field is retained for unsteady magnetic fields of arbitrary configuration, and the parameter H is determined only by the type of magnetic film. For a magnetic film of a selected type of H-SOPEL. is determined once, and the dependencies given above allow processing the results of various measurements.

The described measurement method simplifies the measurement of the spatial distribution of the magnetic field strength along a selected direction.

Claims (2)

1. Popov V.S. Electrotechnical measurements and devices, Rosenergoizdat, M., 1952, p. 303-ЗО6. 2. USSR author's certificate No. 324144, q 01 R 33/02, 1970.