SU1534294A1 - Apparatus for eddy current inspection of distance - Google Patents

Abstract

The invention relates to non-destructive testing and can be used to control a predetermined distance to an electrically conductive product. Improving the accuracy of controlling a given distance to an electrically conductive product is achieved by forming a phase-sensitive total voltage of the operating and compensating eddy-current transducers, which is weakly dependent on the electrical conductivity of the product. The working and compensation eddy current transducers 4 and 5, respectively, are powered by the voltages of two pulse sequences that are 90 ° out of phase with each other. In the device, the phase shift of the sum signal U ₁₂ from the output of the adder 14 is fed to the input of the subtractor 15, from the output of which the output bus 20 supplies a code corresponding to the deviation of the end of the working eddy current transducer 4 from the specified distance. The difference of the distance codes is formed in the subtractor 15 with the aid of the setpoint adjuster 21 of the model code. 2 Il.

Description

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Inventive refers to non-destructive testing and can be used to control a given distance to 1 electron of your product.

The purpose of the invention is to improve the accuracy of controlling a given distance to an electrically conductive product by forming a phase-voltage total voltage of the working and compensating eddy-current transducers, weakly dependent or electrical conductivity of the product.

Tjnii 1 shows a block diagram of the device for monitoring distance, a two-vector diagram illustrating the operation of the device.

The eddy current control device for races nn consists of the first connected I operator 1. frequency divider 2 and phase switch, working eddy current converter 4 and compensating lo ed voltage converter 5, excitation Uiioinite transmogram 1 and 7 eddy current converters 4 and 5 connected to the first and end outputs of the phase resolver 3, the measuring windings 8 and 9 of eddy current pre-electrons 4 and 5 are connected and sequentially opposite and located on the side of the workers' legal transducers Besides that, i o. cipoiuiBo consists of HI in series with non-different low-pass filter 10, s II, quantize 12. Peiister 13 according to the synchronous input, adder 14 and low-frequency pin 16 connected in low frequency, usi-cmr 17, the quantizer 18 and perncipa 19 but the sync input, the output of registers 19 is connected to the second input of the summation JUR 14, O (and the subtractor 15 with an advantageous spike 20 (TWI also contains IKK 21 of the model code connected by the output I) and the control sample 22, mounted at a predetermined distance from the working A common compensation point for eddy current transducer is G common point of measuring tubes 8 and (i but JK 1К1chen to the first output isxoia fi; low frequency open 16, free output (1 and winding 9 sub K) 4ui to nerve} output of the low frequency filter 1U, and the free output and in the limiting 1 winding 8 is connected to the MI gateways to the outputs of the filter inputs 10 and 16 The information inputs of the registers 13 and 19 oi are connected to the divider 2 frequencies, 1 vyury i (we quantizers 12 and 18 units, with the second output of the generator 1

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le.iepaiop 1 generates clock with them ii1 1y.y Ko: oj) i, ie arrive at divide 2 kkYU formative cm code code P i3HtpiKi In fa virasteped 3 of them about azogs napr -keni two phases for pit i and BII zb z melting windings b and 7 swirl- io oiiiiis ipeoopa call ie k and 4 and about Papr

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Neither phases are output as two pulse sequences that are 90 ° out of phase with each other.

When the working eddy current transducer 4 is installed, at a given distance from the electrically conductive product 23 on the measuring windings b and 7, the signals are equal in amplitude, but shifted by 90 °, marked in Fig. 2 as LJi and C2 respectively. The sum signal is depicted by a vector separated from the vectors L) | and U2 at 45 °. Moving the working vortex converter 4 relative to the conductive product 23 in the vicinity of a predetermined distance to it causes a change in voltage Ui. The voltage LJ2 remains unchanged. FIG. Figure 2 shows the vector diagram for the case when the changed value of the voltage on the measuring winding 6 of the working vortex converter 4 is mapped by the vector L l out of phase with respect to the voltage 1 by the angle f2. Pr and this the total output voltage of converters 4 and 5 is equal to Ui2, and its phase shift relative to the voltage U) 2 is equal to the change in phase fi2 of the output signals of converters 4 and 5 is equal to (pi2

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In the device, the phase shifts of these signals relative to the first pulsed serial are converted into codes Ki and Cl from the sum of which the reference code Co corresponding to the phase shift of the signal Uu is subtracted, resulting in code Ki2 outputting the output bus 20 corresponding to the position deviation of the first eddy current transducer 4 from a predetermined distance to an electrically conductive article 23

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For this, signals from measuring windings 8 and 9 are passed through low-frequency filters 10 and 16 The first harmonics of the signals extracted at their outputs are fed through amplifiers 11 and 17 to the first inputs of quantizers 12 and 18, in which they are charged by pulses from the second output of generator 1, and converted into phase-quantized strobe pulses. The output signals of quantizers 12 and 18 arrive at the synchronization input of registers 13 and 19, in which they record the values of the codes that appeared at the time of their arrival at the information input corresponding Enikeev register and equivalent phase shifts output cm vihretokovy.h catch transducers 4 and 5 relative to the first pulse sequence code values recorded in retistry 13 and 19 are applied to inputs of adder 14, and its outputs - to the first

input of the subtractor 15. The second input of the subtractor 15 is supplied from the setter 21, an exemplary code equal to the code at the output of the adder 14, which forms when the operating eddy current transducer 4 is set at a predetermined distance from the electrically conductive product 23. At the same time, from the output of the subtractor 15 to the output bus 20 is given a code corresponding to the deviation of the end of the working eddy current transducer, connected by an input to the generator output via a phase splitter, the first and second outputs to the exciting windings of the working and compensation video x-ray transducers, respectively, connected in series by an amplifier, a quantizer, a register on a synchronizing input and an adder connected to the first output of the subtractor, connected in series by second bodies 4 from a predetermined distance to an electrophore by a low-frequency filter, amplifier, conductive product 23. quantizer and register synchronously, the control sample 22 is made from a sensing input connected to a second, similarly electrically conductive product to the adder input, with an indicator of a sample 23 mat serial This makes it possible to reduce the code connected to the second input, the calculation of the measurement results from the tatel, the second inputs of the first and second

the quantizers are connected to the second output of the generator, the output of the frequency divider is connected to the information inputs of the first and second registers, the measuring windings of the worker and the compensation value to the electrically conductive product, comprising 20 eddy current transducers connecting the overhead transformer us in series-counter and connected to the eddy current transducer with a common point to the first output of the input winding, placed on the side of the second filter, free output of the measuring end of the transducer a low power winding generator, a low winding compensating eddy-frequency filter, an amplifier, a connected transducer is connected to the first

the input of the first low-pass filter, the common point of the measuring windings connected to each other is connected to the second terminals of the inputs of the first and second low-pass filters, and the 30 output of the subtractor is connected to the output bus.

electrophysical properties of the product.

Claims (1)

The invention of the eddy current control device with the output of the low-pass filter, and the subtractor, characterized in that, in order to increase the accuracy of control of a given distance to an electrically conductive product, it is equipped with a compensation eddy current transducer identical to the working frequency divider, phase i eri 2