Quality control radiography

The detection sensitivity of radiography is related among others to the properties and quality of industrial x-ray film systems. Changes of the products, variations due to different emulsions and combinations of products of different manufacturers can influence the decisive properties of film systems as classified in EN 584-1.To ensure the quality of industrial x-ray film systems a system for quality assurance open to all interested parties is proposed which is based on periodical round robin tests and quality controls of the manufacturer or an independent third party institution. 

ASTM El42 Method for Controlling Quality of Radiographie Testing... 

This specification includes requirements for random radiographic inspection for mill quality control. If the 0.90 joint factor is to be used, the welds shall meet the requirements of Table IP-10.5 for longitudinal butt welds with spot radiography in accordance with Table IP-2.2.9. This shall be a matter of special agreement between purchaser and manufacturer. 

Radiography using x- or gamma-rays is well established and is a routinely used technique of non-destructive quality control. It is applied for checking welds, castings, assembled machinery (such as jet engines), and in ceramics. 

It is clear that macroscopic and microscopic flaws affect the properties of PTFE parts. It is important to characterize their impact quantitatively. These flaws can be directly measured by a number of techniques. The measurement methods are complex and not suitable for routine quality control. Macroscopic flaws are frequently detectable visually or by a simple magnifying glass. Internal defects can be detected by x-ray techniques such as radiography. ASTM E94 can be applied as a guideline in establishing procedures. 

Spot Radiography is a random sampling of welding used to aid quality control. About one percent of the weld is examined. 

---