Research Article on Measurements for Digital Radiography Reference Standards
In order to find out defects or discontinuities in aluminum components digital radiography images are used. ASTM creates standards to enhance safety and improve the quality of consumer and industrial products. The ASTM standard is proven and well researched. ASTM has already upgraded from film reference to digital format.
However, ASTM gives all (Digital and Film) radiography reference standards for visual interpretations only. The reference images can only be interpreted manually. It is likely to have errors during interpretation. Human errors are quite natural. Several studies have shown that the same person might give two different levels of defect interpretation when the same image is given after some time gap.
Sample X-Ray Image – Off the Shelf Purchased Brake Lever
Some OEMs like BMW, AUDI, Volkswagen, Ford have developed their own standards based on measurements of discontinuity. For example, Volkswagen uses VW50097 measurement of porosity in castings.
But it is not possible for every buyer to create their own standards. One main advantage in digital radiography is that measurements on images can be done. If we can add measurement in the images, the process of inspection becomes much more effective, faster and easy.
Karma, with three highly qualified and experienced radiographers, has made research on calibration and provided an analysis on gas holes based on ASTM standards to help digital radiography community. This will help the end user to find the level of discontinuity based on measurements. Most of the current digital radiography software interfaces have measurement tools such as lines, circles, squares and rectangles. Team Karma has attempted to correlate the eight degrees (Level 1 to Level 8) for each type of discontinuity in E2422 Digital Radiography Standard with the available measurement tools.
This is not an ASTM Standard. Karma on its own research to support ASTM standard has developed the following analysis.
