Digital Radiography of Welds Using Flat Panel Detector Base Image Sensors

Introduction

The structural integrity of components is controlled by material properties, the presence of flaws, and levels of applied stress. Several factors such as temperature, type of loading, toughness, corrosion resistance, micro-structural stability, cost etc. dictate the suitable material for the desired application. Even after proper material selection, engineering components can be subjected to various non-destructive testing methods to ensure there are no flaws that could lead to failure during equipment service life. Conventional film radiography is the most frequently used technique for detecting flaws. Over the last decade, digital radiography has emerged as an effective alternative to film radiography. Unlike a film radiograph, the digital radiograph is not an inflexible snapshot frozen in time. Several image processing techniques can be applied on digital images to extract various information. This article briefly outlines the different flat panel sensors available and their use during weld inspection, as well as the usefulness of various image processing options in digital radiography. 

Digital Radiography

Digital radiography is made up of a set of techniques which produce virtual images that may be analyzed, parsed, shared, re-produced and saved with full traceability. The most popular techniques in this field are fluoroscopy, image plate base computed radiography, and digital detector arrays (i.e. flat panel detectors). The operating principles for each method are different, but all of them can produce digital radiographs. There are numerous advantages of digital images, such as no requirement for wet chemical processing, the ability to digitally archive images, better organization and accessibility easier transmission of images through multiple digital channels, etc.