SU1499210A1 - Apparatus for teddy current check - Google Patents

Abstract

The invention relates to non-destructive testing of materials and products and can be used in the development of products for disposable and non-removable defects. The aim of the invention is to increase the reliability of control by recognizing the type of defect and sorting out on the elimination of defects. The bridge measurement circuit 4 extracts an information signal from which, after detection, harmonic components are extracted that carry information about the size and type of the defect. The magnitudes of the harmonic components are compared with the given values, and when these values are exceeded, the AND 28 scheme triggers, causing the products to be sent to an unrecoverable defect. When only the comparator 17 is triggered, a signal appears at the output of the AND 11 circuit, which causes the items to be sent to a disposable scrap. 1 il.

Description

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The invention relates to non-destructive testing of materials and measurements and can be used to locate defects in metal products.

The purpose of the invention is to increase the reliability of control due to the recognition of the type of defect and the screening of the elimination of defects,

The drawing shows a block diagram of a device for eddy current testing.

The device contains a working 1 and compensatory 2 windings of the eddy converter and a generator 3 connected in series, a bridge measuring circuit 4 to which the worker 1 and compensating 2 windings are connected, detector 5, filter 6, expander 7, -integrator 8, comparator 9, the inverter 10, the circuit AND II, the power amplifier 12. and the electromagnet 13. In addition, the device contains a series-connected filter 14 connected to the output of the detector 5, rectifier 15, integrator J6, comparator 17, the output of which is connected to the second input of the circuitAnd 11, the circuit And 18, the second input of which is connected to the output of the comparator 9, the power amplifier 19 and the electromagnet 20.

The device works as follows.

The generator 3 excites the working winding 1 of the eddy current transducer, interacting with a controlled product (not shown). The disturbance signal is induced in the compensation winding 2. The bridge measurement circuit 4 selects the useful signal that is detected by the detector 5. Two harmonic components are extracted from the received signal envelope using filters 6 and 14, after rectification in rectifiers 7 and 15 and inyu .4

In the integrators 8 and 16, the signals are compared in the comparator 9 and 17 with the threshold values of the admissible size of the defect.

Both signals then arrive at circuits AND 11 and 18, and the signal from the low-frequency harmonic is inverted before arriving at circuit II. At the same time, signals from an unrecoverable defect trigger cxe№J and 18, and through the power amplifier 19, the electromagnet 20 sends a controlled item to the marriage.

In the case of a fixable defect, only the AND circuit 11 is triggered and, through the power amplifier 12, the electromagnet 13 sends a monitored product to eliminate the defect.

Claims (1)

Invention Formula A device for eddy current testing, containing a working and compensation for the eddy current winding and a series-connected generator, a bridge measuring circuit to which the working and compensation winding of the eddy current converter and a detector are connected, in order to increase the control reliability, connected by a first filter connected to the detector output, a rectifier, an integrator, a comparator, an inverter, an AND circuit, a power amplifier, and an romagnitom and series connected second filter podklyuche1shym to the output detector, rectifier, integrator, comparator, whose output is connected to second input of first AND circuit, AND circuit, the second input of which is connected to the output of the first comparator, a power amplifier and an electromagnet.