X-rays apparatus in the nature of testing and measuring equipment for determining flaws, stress, fatigue, composition and structural analysis of materials; radiological apparatus for industrial purposes; X-rays producing apparatus and installations, not for medical purposes, namely, X-ray transmission imagers and X-ray fluorescence analyzers; X-rays tubes not for medical purposes; X-rays installations, not for medical purposes, namely, X-ray transmission imagers and X-ray fluorescence analyzers