SU1227943A1 - Method of article electromagnetic inspection - Google Patents

Abstract

The invention relates to Hepaspyuiaio eddy current testing and can be used to control the movements of ferromagnetic and non-magnetic conductive products, as well as the thickness of dielectric coatings on them. The purpose of the invention is to increase the control accuracy and expand the functionality due to the fact that the converter is driven by currents of three different frequencies, the amplitude and phase of the compensating voltage are changed to equal the amplitudes of the output total voltages of the converter at three frequencies and the resulting amplitudes are determined controlled parameter. IN Is5 CO

Description

The invention relates to non-destructive eddy current testing and can be used to control the movements of ferromagnetic and non-magnetic conductive products, as well as the thickness of dielectric coatings on them.

11, the spruce of the invention is new, the accuracy of control due to the adaptation to the conditions of control, and the expansion of functional possibilities due to the possibility of control of products, both magnetic and nonmagnetic, with an unlimited value of electrical conductivity.

The method is constructed as follows.

The transducer is installed above the controlled product. With the nomonghiu generator, m) and the frequencies f |, I, -),

--fy- exciting electromagnetic

current field and compare the amnality of the output nanowire of the transform gel to each other. The frequency li is initially determined from the condition of an intact coil, at which, for example, the thickness or diameter of the product is sandwheel different 1) 1H1, it sets the total depth of rotation of the eddy currents and

squeeze

fji (i.niT / - /2l/:Tsiam.1m/).1... ;,, T, where f.j - the maximum frequency is chosen

 conditions

R. h | d. () am; 1ks / | .1mi |

 R / 2 / c. 1 (1 (Tmn||/im;1Кс; 1-.- (7 м а КС Н МП КС

 Llmhi

where R is the radius and the transformation.p;

j.i (i-- magnetically stable; Omax, am11. -S, respectively, maxim.ma; 1no and. the minimum possible values of the specific electrical density of the product;

JUKIKC.UMHII are, respectively, the maximum and minimum possible values of the relative magnetic propagation and hiring of the product; 6 is a generalized parameter (fiojii is its optimal value). As follows from the theory of the eddy current tube and the analysis of the output converter panel, the amplitude of the output voltage of the eddy current probe is different at different frequencies. However, the year | | rafes of the output nanowire of the eddy current transducer located above the ferro1-nit1P 1m conductor and a non-magnetic product, depending on the dimension (a, | d) of the product, can be unsyncated by an arc of a circle with a suitable choice of the origin of coordinates. curve. At the same time, the amplitudes of the output voltage of the converter turn out to be the same for different values of the parameters of the hodograph and thereby eliminate the norpenjHocTb measurement of the parameter H - Y, where h is the distance between the windings of the converter and the surface of the product, from the change in center and point.

The output vector of the converter, OUTLOOKING, from the center of the arcs of circles, limited by the values of,,,, 1. ,.ax, alternately form the frequency f and fs and from the variable A. amplitude compensate) which

vector is summed with the output voltage of the converter. A change in the amplitude of the compensating voltage and osunchest until the amplitudes of the total output voltage of the converter are equal to two frequencies f | and f, - ;. Then alternately set the frequencies 1 1 -j and f.-j excite the current, and compare the output total voltages of the converter. If the amplitudes of the oscillations are not paiiHbi, then with the help of KOMnenca i Opa, the phases of the gearings of the oscillations at frequencies f2 and f.-j are changed up to the moment of equalization of cvMMapinjx output nanometers (111) e) at these frequencies.

Then the Biioiib sequence 11o sets the frequencies fi and t: -; exciting current if at

this amnlitu.; of 1 stresses not conforming) 1, again change the magnitude of the com- municated stresses; io the moment of time, amp.chitud sums. marmp1s1 X cap rpc and and converse.

Thus, HTepaiiHonno because of the amplitude and phase number of the secondary pan,

achieve equal values of the total transactions of the L. i-.bi.Ji UiiMNf) Uni.ixf.-j. The number of iterative ones is determined by a given degree of versatility ii and of the counterpart of the item and e; 1I have no practical problems like the level of three or four.

Using the n) e.rviaraeMoro method with a tunable in the process of contact; 5o the coordinate system of the output of the voltage of the transient current transducer (the model makes it possible to measure with

The use of both ferromagnetic and non-magnetic products of various shapes and 5az.measures, as well as that of dielectric coatings on them.

45

Claims (1)

Formula invented C.1.of e. 1ectromagitic1 about a co2girl production ;-; 1, concludes that the converter in a controlled product excites all 1 currents, it is the com- mand voltage, sum, etc., which is applied. The voltage of the transducer, which generated the total output voltage of the transducer, does not allow for the amplitude B1) of the input voltage and is determined by a controlled parameter that differs from that of the controlled TOHI- IOCTH controls and the spreading of functionality, but (i) the user, excite by currents three times 1223943 34 personal frequencies, change the amplitude and phase of the transducer at three frequencies and compensating voltage to equal to the amplitude value obtained determine The amplitudes of the output total voltage are the controlled parameter of the product.