SU756466A1 - Device for non-destructive inspection of ferromagnetic materials - Google Patents

Description

The invention relates to the field of technical training tools and can be used to demonstrate non-destructive testing of ferromagnetic materials.

A training device for non-destructive testing of ferromagnetic materials is known, which contains a source of magnetization reversal voltage, to the output of which one of the conclusions of the magnetization reagent coil is connected and the measuring coil, amplifier, are connected in series with each other. detector and electron beam indicator [1].

The disadvantage of the known device is the difficulty of quantifying the output parameters of the device, which causes a lack of clarity of control. The aim of the invention is to expand the functionality of the device by increasing the visibility of the control.

The goal is achieved by the fact that the device contains a resistor, through which the second output of the magnetization coil is connected to one of the terminals of the source of the magnetization reversal, a differentiation unit, analog 2

A gob storage unit, a unit for generating a reference voltage and switches, with one of the detector outputs connected respectively to one of the terminals of the first switch and to the input of the differentiation unit, the outputs of which are connected respectively to one of the terminals of the second switch and to the second terminal of the second switch, the switching contact of which is connected to one of the analog storage inputs

15 of the unit, the other input of which ^ is connected to one of the outputs of the unit for generating the reference voltage, while the second output of the unit for generating the reference voltage is connected to

20 second entrance electron beam

indicator, and the input unit of the formation of the reference voltage through the switching contact and the second terminal of the second switch is connected to

25 output magnetic reversal coil ..

FIG. 1 shows a block diagram

training device for non-destructive testing of ferromagnetic materials? in fig. 2 - stress curves: (a - voltage of the magnetizing coil.

756466

b ~ voltage in the measuring coil, in - voltage at the detector output); in fig. 3 - stress curves explaining the operation of the device;

(a is the voltage at the detector output, b is the combined voltage of the differentiator and the reference voltage, the voltage at the output of the shaper of the reference voltage, g is the voltage at the output of the analog storage device).

The block diagram of the device (Fig. 1) includes a remagnetization coil 1 connected to an alternating bias voltage generator (not shown) and a resistor 2, a ferromagnetic sample 3 and a two-section measuring coil 4. An amplifier 5 is connected in series to the measuring coil 4, detector 6 and electron beam. indicator 7. One of the outputs of the detector 6 is connected to the input of a differentiation unit 8, the outputs of which through switches 9 and 10 are connected respectively to an analog storage unit 11 and a unit 12. for generating a reference voltage.

The device, for example, in the mode of measuring the instantaneous value of the envelope for a given value of its derivative works as follows.

The input unit 12 of the formation of the reference voltage by means of the switch 10 is connected to the output of the unit 8 differentiation, and the input of the analog storage unit 11 by means of the switch 9 to you. detector 6.

The generator of the magnetization reversal creates a voltage at the output (Fig. 2, a), as a result of which a current flows through the reversal magnetization coil 1, which peremagnetizes the ferromagnetic sample 3 under study.

In the measuring coil 4, an incident EMF from irreversible changes in the magnetization of sample 3 is induced (Fig. 2.6). '

The signal is amplified by the 5th amplifier is detected by the detector (Fig. 3, a). The differentiation unit 8 forms a derivative of the EMF envelope, and in the reference voltage generation unit 12, a comparison is made with some specified value of the reference voltage (Fig. 3, b). At the moment of equality of these signals, the block 12 generates a pulse (Fig. '3, c) arriving at the input of the analog storage unit 11, which records the instantaneous value of the EMF envelope, and. to the input of the electron-beam indicator 7.

The output signal of the analog storage device is shown in FIG. , 3, city · ’

Since; the output of the differential differential block 8 is connected to the vertical deviation input of the electron-beam indicator 7, its derivative along with the envelope is displayed on its screen.

The composition of the analog storage unit 11 includes an arrow indicator (not shown), which allows with sufficient accuracy to estimate the values of the measured parameters.

Resistor 2 in the circuit of the magnetizing coil 1 is required in the measurement mode at a given intensity of the magnetization field.

The invention allows students to imagine the relationship of the characteristics of magnetic noise with the structure and stresses in a ferromagnetic sample, since not only the type of EMF envelope is displayed on the screen, but also qualitative changes in the shape of the envelope are confirmed by the readings of the analog storage device indicator.

Claims (1)

Claim A training device for non-destructive testing of ferromagnetic materials, containing a source of magnetization reversal voltage, to the output of which one of the conclusions of the reversing magnetizing coil is connected, and the measuring coil, amplifier, detector and electron beam indicator connected in series with each other, in order to extend the functionality by increasing the visibility of the control, it contains a resistor, through which the second output of the magnetizing coil is connected to one of the terminals of the transistor source low voltage, differentiation unit, analog storage unit, reference voltage generation unit and switches, while one of the detector outputs is connected respectively to one of the terminals of the first switch and to the input of the differentiation unit, whose outputs are connected to one of the terminals of the second switch, respectively, to one - from the inputs of the electron-beam indicator and to the second terminal of the second switch, the switching contact of which is connected to one of the inputs of the analog storage unit a, the other input of which is connected to one of the outputs of the reference voltage generating unit, while the second output of the reference voltage generating unit is connected to the second input of the electron-beam indicator, and the input of the reference voltage generating unit through the switching contact and the second terminal of the second switch is connected to the output of the magnetizing coil .