Discussion on Using Filter to Expand the Testing Scope of Small Diameter Welding Tubes

A method for expanding the testing scope of small diameter welding tubes was presented. This method used the filter to expand the testing scope. And it was based on the analysis of the influences of scattering ray. It was explained that the material and the size of the filters played an important role on the testing scope. Its validity was proved by the turning experiment and its operation was simple and convenient.