NDTnet 1998 Aug, Vol.3 No.8

Full-Text - Abstract

Despite of an immense improvement of non-destructive testing, the results of the evaluation depends on the inspector who does it. Absolutely clear for the material testing experts that the most important part of the reliability is the operator, but not the perfect one. So it is very important and a hard problem to measure the reliability of the operator and the harder problem is to develop the skill. Well-known is the one of the most effective methods to measure the personal reliability to organise a Round-robin test, and the only way to develop it is to do practice from time to time.

In Hungary a Round - robin test was organised to measure the reliability of the NDT personnel in the frame of the TINCA ~ PLUS project. The TINCA and TINCA-PLUS program are European projects for management of the remaining life of power plant components by means of an intelligent software tool.

The organisation of the round robin test happened in the following ways: a certain ultrasonic equipment and a strict testing technology was given to the voluntary operators. They examined a 60 mm thick welding which contained artificial flaws. The work took approximately 8 hours. This test was performed by 24 operators coming from 8 Hungarian NDT laboratories.

You can evaluate the reliability of the operators, if you have the real values of measured values. In the ultrasonic test the real values can be determined by the calculation of mean of measured values, by more accurate automated ultrasonic tests, by using the planned measurement after a correct manufacturing, and by destructive testing. We can discuss the question which is the best real values by comparing the manual testing results.

In the process and the results of the evaluation provided interesting experiences for us. For example, the experts of reliability all over the world use several mathematical methods to evaluate the performance of operators. But the operators aren't able to understand the results, and the laboratory leaders don't know which are the acceptable level of a certain method. Who will tell the operators and why that they will have to do a refreshment practice? The other problem is that in our work there were only volumetric artificial failures and planar and real discontinuity weren't prepared.

The customer of NDT laboratories expect to increase and demonstrate the reliability of the testers. For this reason we have to develop the measuring methods and specify the conditions f the Round-robin tests. Suggestions will be made in the paper.

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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