Leak testing of in-service large high-vacuum system is one of the difficult problems in leak detection techniques. In this paper, on basis of leak reason and characteristics of inservice large high-vacuum system, a new helium mass spectrometer leak testing system and method are introduced. Due to improvements in testing system design, sniff probe and sensor mass analyzer, the sensitivity of the leak testing system is much higher than that of the conventional helium leak testing and the response time of leak testing system is much shorter than that of the conventional helium leak testing. By this way inservice leakages of large high-vacuum can be inspected simple and effective. A new method of pre-test for micro-leakage of materials and welds in large high-vacuum system by ultrasonic inspection is also described. Its transducers and relative technology has been developed. By this way the discontinuities in materials and welds which may form micro-leakage can be detected before operation. so that inservice leak of large high-vacuum system can be minimized. The experimental results and practice show that the problem of inservice leak in large high-vacuum system can be satisfactorily solved by the above two ways.
Publication Source: Trends in NDE Science & Technology; Proceedings of the 14th World Conference on Non-Destructive Testing, New Delhi, 8-13 December 1996.full paper not received Publisher:Ashgate Publishing Company
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