SU1656442A1 - Linear magnetic field transducer with heat excited elements - Google Patents

Abstract

The invention relates to non-destructive testing of materials and products and can be used to visualize the quality of ferromagnets. The purpose of the invention is to increase the sensitivity of the converter due to the thermal excitation of the magnetically sensitive node. The degaussing current shaper 12 creates an alternating voltage in the degaussing winding 13, which causes the ferromagnetic cores 9 to heat above the Curie point temperature. During their subsequent cooling below this temperature, the magnetic permeability increases sharply, which leads to the appearance of a current pulse in the output windings 14. The magnitude of which depends on the residual magnetization of the product under test. Sequencing the scan of the product being monitored in this way creates in the memory unit 5 a two-dimensional picture of the distribution of the magnetic fields displayed on the screen of the video monitoring unit 6 1 sludge. (L

Description

The invention relates to the non-destructive testing of materials and products and can be used to visualize the quality of ferromagnets.

The aim of the invention is to increase the sensitivity of the converter due to the thermal excitation of the elements of the magnetosensitive node.

The drawing shows a block diagram of the device.

The device comprises an electromagnet 1, a magnetically sensitive node 2, a detecting amplifier 3, a video amplifier 4, a memory unit 5, a video monitoring unit 6, and a scan unit 7, connected in series.

Magnetosensitive node 2 contains a single-line transducer

8, made, for example, in the form of ferromagnetic cores 9.1-9.N, arranged in a ruler, connected in series to the DC generator 10 and the excitation winding 11, penetrating all the ferromagnetic cores

9, a demagnetization current driver 12 connected in series to the sweep unit 7, and a demagnetization winding 13, covering all ferromagnetic cores 9 in series, output windings 14.1 - 14.N, covering the corresponding ferromagnetic cores 9.1 - 9.N, and switch 15, N whose inputs are connected to the corresponding output | O

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14.1 - 14.N; The N + 1 input is connected to the sweep generator 7, and the output of the switch 15 is the output of the magnetically sensitive node.

The device works as follows.

The electromagnet 1 magnetizes a controlled product (not shown in the drawing), on the surface of which a magnetic relief appears, correlating with its internal structure. The magnetically sensitive unit 2 is placed on the surface of the monitored product, and according to the signals of the sweep unit 7, the demagnetizing current shaper 12 forms a packet of pulses in degaussing winding 1 that causes the ferromagnetic cores 9 to heat above the Curie point.

When cooling the ferromagnetic cores 9, their magnetic permeability increases dramatically, and since the DC generator 10 supplies current to the excitation winding, a signal depending on the external magnetic field arises in the output windings. The received signal through the switch 15 is supplied to the detecting amplifier 3, and through the video amplifier 4 the information signal about the magnitude of the magnetic field at this point is stored in digital form in the memory block 5.

When all the ferromagnetic cores 9.1 to 9.N are sequentially interrogated and the magnetically sensitive unit 2 moves along the surface of the controlled product in memory block 5, a two-dimensional shape is formed.

Editor M. Bokareva

Compiled by Yu.Glazkov Tehred M. Morgental

picture of the distribution of magnetic fields, which is displayed on the screen of the video monitoring unit 6.

Claims (1)

Invention Formula Linear transducer of a magnetic field with thermal excitation of elements, containing an electromagnet, a magnetically sensitive unit connected in series, made in the form of a single-line transducer from ferromagnetic cores, a detection amplifier, a video amplifier, a memory unit and a video control unit and a scanner unit whose outputs are connected to the memory unit and a video monitoring unit, characterized in that, in order to increase the sensitivity, it is provided with series-connected direct current generator and an excitation winding covering all ferromagnetic cores, serially connected by a demagnetization current driver, whose input is connected the cores, the switch inputs are connected respectively to the output windings and the scanner unit, and the output is the output of magnesium ochuvstvitelnogo node. Proofreader M.Maksimishinets