1985 Volume 3 Issue 1 Pages 16-21
A reliable method of weld-line detection for electron beam welding has been developed by incorporating semiconductor X-ray sensor and signal processor.
The fundamental characteristics of weld-line detection and the signal processing to eliminate the noise component are studied. The sensing methods of X-ray and scattered electrons are compared under the condition of practical use.
The conclusion obtained are summarized as follows:
(1) The X-ray sensing method is very reliable, comparing with the scattered electron method, because of its durability against metal vapours and sputters, and its complete shielding property against an electromagnetic noise.
(2) The processing of the weld-line signal, such as a time averaging, is very effective for high resolving power, because the weld-line detector is used in the environment of high noise level caused by high-frequency inverters, power contactors, and so forth.