SU1485114A1 - Adjusting specimen for electropotential flaw detection - Google Patents

Description

The invention relates to non-destructive testing and can be used for graduation and adjustment of means of electrical potential flaw detection. The purpose of the invention imitation of subsurface defects

and downsizing. It is achieved by using the symmetry of the electric field created by an electropotential transducer in the control zone. Tuning ob2

The sample consists of an electrically conductive plate 1 with side faces normal to the working surface of the sample. On the side of one of the side surfaces of the plate 1 along its normal, a cavity 2 is made half of the length 1 of the simulated defect. The length b of the trace of cavity 2 on the side surface of plate 1 corresponds to * the depth of the simulated defect, and the distance from the working surface of the plate to cavity 2 corresponds to the depth of the simulated defect. For operation with a tuning sample, conductive electrodes 3,4 and potential Electrodes 5,6 of an electric-potential converter are brought into contact with the corresponding face of the tuning sample. All other conditions being equal, the sample has half the size and allows simulating the effect of subsurface ^ defects. This * provides the possibility of calibration of electric potential flaw detectors in relation to subsurface defects. 1 il.

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The invention relates to non-destructive testing and can be used for the calibration and adjustment of the means of electropotential defectoscopy.

The purpose of the invention is to imitate subsurface defects and reduce ^! dimensions,

The drawing shows the proposed sample.

A tuning sample for electropotential flaw detection consists of an electrically conductive plate 1 with lateral faces normal to 15 of the working surface of the sample. On the side of one of the side surfaces of the plate, a cavity 2 is made normal to the depth of the plate 1 by half of the length 1 of the simulated defect. 20 The length H of the trace of cavity 2 on the side surface of plate 1 corresponds to the depth of the simulated defect, and the distance cG from the working surface of the plate to cavity 2 corresponds to the depth of the simulated defect. ί

Setting electropotential flaw detector using the proposed sample is as follows. thirty

The current-carrying 3 and 4 and potential 5 and 6 electrodes of an electropotential transducer are brought into electrical contact with the edge of the tuning sample formed by the intersection of the working and side surfaces. In this case, the voltage measured by the flaw detector and at a given current I through current electric drives will be 2 times the voltage, dd arising ¹ at the output of the electric-potential converter under the action of a simulated defect. At the same time, the voltage υ _σ , measured on the defect-free area of the sample, increases by 2 times. The voltage Q _o can be obtained by setting the transducer, for example, on the opposite side of the sample.

In electric potential flaw detectors in order to eliminate the influence of specific electric conductor4

ti <e measured at the defective portion of the voltage and voltage normalized and ₀ This is achieved, e.g., by ensuring the conditions _of C

= const due to adjustment of current I before measurement. Therefore, taking into account the preliminary adjustment of the flaw detector on the defect-free area, the magnitude and, measured on the tuning sample, exactly corresponds to the voltage arising from the effect of the simulated defect. We now show that the voltages and and ϋ _ο for a given current I really exceed 2 times the voltage and 'and that occur when measuring an object with a simulated defect. The ratio and _o = 2M ° follows directly from the fact that the electrical resistance between the potential electrodes, as a result of eliminating half of the electrically conductive medium, increases by 2 times. To substantiate the ratio and "2", we shall clarify the conditions under which the quantity and * are measured. Before measuring .and ¹ electropotential transducer set symmetrically with respect to the defect. With this signal. from the output of the converter has a local extremum and equally changes with symmetric displacement of the converter relative to the defect.

Claims (1)

Claim A tuning sample for electropotential defectoscopy, consisting of an electrically conductive plate, with at least one lateral surface, normal to the surface of the sample, and a cavity corresponding to the simulated defect, is so that imitations of subsurface defects and size reduction, the cavity is half the length of the simulated defect on the side of the side surface normal to the sample surface, and normal to this surface.