SU1229672A1 - Eddy-current device for inspecting electro-physical parameters - Google Patents

Abstract

This invention relates to non-destructive testing by the eddy current method. The purpose of the invention is to improve the accuracy of control due to the elimination of the error caused by variations in the characteristics of the signal processing unit .. and the initial voltage of the eddy current converter unit when the frequency of its excitation current varies. The device consists of a connected in series controlled oscillator, an eddy current converter and a controlled frequency converter, a controlled compensator, and a controlled signal processing unit. The control inputs of all units are designed to be connected to a control system, in which quality a microprocessor or microcomputer can be used. The device performs multi-frequency sequential control over the quadrature components of the signal by appropriately adjusting the frequency of the controlled oscillator and fixing the obtained results in the controllable signal processing unit. The dependence thus obtained reflects the electrophysical properties of the controlled product. 2 Il. from F (L to 1 OE)

Description

The invention relates to non-destructively, controlled by the method of vortex shackles and can be used in engineering and instrument-making industry for measuring the electrophysical parameters of materials and products.

The aim of the invention is to improve the accuracy of control by eliminating the error caused by variations in the characteristics of the signal processing unit and the initial April 1 of the eddy current transducer unit (ETP) when its excitation current frequency is changed,

FIG. 1 shows a block diagram of an eddy current device; on ig. 2 is a block diagram of a converter and a compensator.

The device contains a serially controlled generator 1, an eddy current converter 2, a controlled frequency converter 3, a controlled compensator 4 and a control for the signal processing unit 5, the output of which is intended for connection to the display and sorting cluster (not shown).

The controlled frequency converter 3 comprises a serially connected control synthesizer 6 frequency (FIG. 2), the input of which is connected to the controlled oscillator 1, a lance converter 7, the second input of which is the input of the controlled frequency converter 3, and a filter 8 whose output is the output of a controlled frequency converter 3.

Controlled compensator 4 contains a voltage transformer 9 connected in series, the input of which is connected to the controlled generator 1, a control voltage divider 10 and an adder 11, the second input of which is the input of the controlled compensator 4, and the output of its output.

The reference input of the controlled signal processing unit 5 is connected to the controlled oscillator 1, and the control inputs of the controlled oscillator 1 управ controlled frequency synthesizer 6, the controlled voltage divider 10 and the controlled signal processing unit 5 are connected to the control system (not shown).

The device works as follows.

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The control inputs of the controlled oscillator 1 (Fig. 1) are set to the frequency Si. and the amplitude of the excitation current of the eddy current transducer 2, and at the control inputs of the frequency converter 3 - the frequency j, -f. The signal from the internal current converter 2 is fed to one input of the balanced converter 7 (Fig. 2), to the other input of which voltage is supplied by the frequency uJ, from the output of the frequency synthesizer 6, and the side frequencies of the signal are formed at the output. Filter 8 selects the first harmonic of the frequency of the signal Q, -, f,

A sinusoidal signal with frequency f is applied to one of the inputs of the adder 11, and the sinusoidal quadrature voltages are fed to the other two inputs. They are formed by a voltage form converter 9 from quadrature pulse voltages of frequency f produced by controlled generator 1, and are controlled in amplitude by a controlled voltage divider 10, the coefficients d "of which are given by the control inputs, In the absence of a control object ( ) the division factors Q are set so that the signal at the output of the adder 11 is zero. In this way, the initial voltage of the eddy current transducer 2 is compensated.

When interacting with the control object, the signal is fed to the input of the signal processing unit 5. It performs amplification, detection and quadrature components of the signal, as well as conversion into a digital code, which is transmitted to the recording unit, and then processed by the operator or computer,

With multiparameter-multifrequency monitoring, different values of the excitation current frequency are set. In accordance with this, the frequencies at the output of the synthesizer 6 are set to the frequencies CL (), J,,. . ujj. . uJ,

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so 1. Due to this, the error caused by variations in the characteristics of the signal processing unit and the initial voltage of the eddy current transducer when the frequency of its excitation current is changed is eliminated, the operating frequency range of the device is expanded and its circuits are simplified.

Claims (1)

Invention Formula An eddy current device for monitoring electrophysical parameters, containing a series-connected controlled generator and eddy-current converter and a controlled signal processing unit, the supporting input of which is connected to a controlled generator, in order to improve the accuracy of control, it equipped with a controlled frequency converter, consisting of a series of a controlled frequency synthesizer, the input of which is connected to a controlled generator, a balanced converter, the second input of which is connected to an eddy current converter, and a filter, as well as a controlled compensator consisting of voltage transducers connected in series to a controlled generator , controlled divider and adder, the second input of which is connected to the filter, and the output to the controlled signal processing unit. 1 LT Editor I. Nikolaichuk Compiled by Y. Glazkov Tehred V. Kadar Order 2445/44 Circulation 778. Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4 Corrector A, T sc