NDTnet 1998 Aug, Vol.3 No.8

Abstract

Introduction.
The increase of ultrasonic nondestructive testing reliability is connected to exception of the subjective factor from an its results estimation. For the decision of this problem is developed or automated installation, or scanning system, supposing a fixed trajectory of the transducer moving. Further development of the ultrasonic testing means we connect to developed principles of construction automated systems. The usually automated system is constructed on algorithm, according to which, inside a testing product acoustic oscillations in a direction of possible development of defects are raised. Then in a chosen temporary interval, appropriate to testing area, pulses coming on the receiver are analyzed. Depending on that they exceed whether or not on amplitude size of a pulse from extreme allowable defect, decision on the validity or unsuitability of a product is accepted. In case of a complex surface and internal structure of object there are the problems with scanning of object and with the analysis of received results. A way of the automated monitoring system construction on a principle of selftraining is offered.

Principle of work.
From the first, scanning a sample in immersion bath is made by the precision moving by transducers system on a given trajectory. Through given by program interval x a signals from the receiver are recording. Upon termination of a scanning cycle in memory of the computer there is the image of a product F_o(x). The further testing is made by comparison of a written down image of a exemplary product F_o(x) with images of testing objects F_m(x). Comparison received images of a products are realized on reference points, located inside a bath or characteristic points on the product. The similar systems well work at the testing of the precision products. At the testing of products carried out inside the same allowance it is necessary to carry out additional mathematical processing of received images, connected to smoothing of received images of products and correlation under estimations of defects. Structure of installation enter the source-receiver of acoustic oscillations, block of ultrasonic transducers, system of scanning, control system engines, block of the analysis and registration.

Conclusion.
The convenience of the offered monitoring system consists in an opportunity fast adjustment in conditions of many nomenclature manufacture, reception of the protocol of the testing results, opportunity of use of the unskilled personnel. By an offered principle installations for the testing of welding by explosion of cases of plunger pumps, details of air engineering and other ere developed.

Abstract Source:
Book of Abstracts, 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN: 87-986898-0-00

Full-Text Source:
Proceedings of the 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN:

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