SU1620929A1 - Device for checking elongated metal articles - Google Patents

Abstract

The invention relates to non-destructive testing of materials and products and can be used in the inspection of extended products. The aim of the invention is to increase the reliability of operation and control reliability by registering the unbalance of the eddy current transducer and changing its design. The generator 1 excites the eddy current transducer 3, information from which, after amplification and processing, is displayed on the recorder 8. At the same time, the constant component of the signal is integrated and through the logic block 12 enters the control and signaling unit 13, which records the state of the eddy current transducer 3 and the presence of a controlled product, and in violation of the modes of operation, the control and signaling unit 13 generates a corresponding signal. 2 Il ,. (WITH

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The invention relates to a technique for non-destructive testing of materials for products and can be used in the inspection of extended products.

The purpose of the invention is to improve the reliability of operation and reliability of control by registering the unbalance of the eddy current transducer and changing its design.

Fig. 1 shows a block diagram of a device for monitoring extended metal products; in fig. 2 - eddy current transducer.

The device contains a series-connected generator 1, indicator 2 of the impedance coil of the eddy current transducer, eddy current transducer 3, amplifier 4, selective amplifier 5, power amplifier 6, amplitude-phase discriminator 7 and recorder 8. In addition, the device includes a biasing unit 9 and sequentially connected linear rectifier 10 connected to the output of power amplifier b, integrator 11, logic unit 12, the second input of which is connected to indicator 2 of full center inductor coil eddy current transducer and the block 13 control and signaling.

The eddy current transducer 3 contains a ferromagnetic continuous cylinder 14 (Fig. 2) with grooves 15 and inductor and measuring windings 16 and 17.

A ferromagnetic continuous cylinder 14 is mounted in a magnetization unit 9 comprising a bias coil 18 and a housing 19. In FIG. 2 also indicates a controlled article 20.

The device works as follows.

The generator 1 generates a sinusoidal voltage, which is supplied to the eddy current transducer 3 through the indicator 2 of the impedance of the INDUCTOR SWITCHING

converter The eddy current signal 3 carries information about defects and interfering factors.

After amplification from the output of amplifier 4, the signal is fed to the input of the selective amplifier 5, and from the output of the latter to the input of amplifier 6 of power. From the output of amplifier 6, the power voltage is applied to the signal input

amplitude-phase discriminator 7, the second input of which receives the reference voltage from the output of the generator 1. At the output of the amplitude-phase discriminator 7, a signal from the defect is output, which is fed to the input of the recorder 8.

The current flowing through the bias winding 18 of the bias magnifying unit 9 creates in the housing 19 a magnetic flux that penetrates the walls of the ferromagnetic cylinder 14 and the product under test 20. In this case, the magnetic permeability of the material of both the product 20 and the ferromagnetic continuous cylinder 14 tends to be one. This leads to a sharp increase in the penetration depth of the electromagnetic wave into the metal, and an electromotive force is induced on the measuring windings 17, which is determined by defects and interfering factors. The voltage of the differential signal is fed to the input of amplifier 3. Next, from the output of power amplifier 6, the voltage of the differential signal is fed to the linear rectifier Yu, where from a sinusoidal voltage is converted to direct voltage, then the constant voltage is fed to the integrator 11, constant the time of which is determined by the speed of movement of the product 20 in the eddy current transducer 3. From the output of the integrator 11, the voltage is fed to the input of the logic unit 12, which outputs a signal in case of a sharp decrease in noise, which occurs when turning off the bias coil 18 or stopping the movement of the test item 20.

At the output of the indicator 2 impedance of the inductor winding of the eddy current transducer, the signal occurs when the bias winding 18 is disconnected or the inductor winding 16 is broken. It is fed to the input of the logic unit 12. In the event that the movement of the controlled article 20 stops moving, the signal does not occur. From the output of the logic block 12, the signal is fed to the input of the control and signaling unit 13, which fixes the breakdown of the eddy current transducer 3 or the cessation of movement of the monitored product 20.

Claims (1)

Apparatus of the Invention A device for monitoring extended metal products containing