Non-destructive Testing (NDT) based on Gamma and X-ray is one of the methods used in industry to inspect parts for cracks or other defects during the manufacturing process. Usually the inspection is maintained inside a production line, but some parts such as shipyards, aircrafts, as well as pipes, and oil/gas tanks are inspected in the field. For example in the oil and gas industry mobile non-destructive testing is used for the detection of deposits and corrosion as well as for weld inspection on pipelines in the field.
Traditionally radiographic testing in the field was carried out using film but nowadays digital X-ray radiography is increasingly being used for on-site NDT inspection. The use of mobile sources (X-rays or gamma rays) along with a lightweight portable detector as imager is a viable option. Digital Detectors are beginning to replace film, as digital imaging is more cost-efficient and real-time imaging offers the advantage of immediate on-site image evaluation and thus an improvement in inspection efficiency. In addition, due to the high safety guidelines for the inspection of pipelines, high requirements lend themselves to the image quality of such a mobile Digital Detector Array (DDA).
Varex industrial wireless Digital Detector Arrays XRpad2 3025 HWx-i and XRpad2 4336 HWx-I have been engineered for mobile non-destructive testing. The XRpad products have excellent resolution and image quality. They provide features like continuous imaging with up to 9 fps, on-board averaging, power saving, Automatic Exposure Detection (AED) and backscatter shielding. These detectors are designed to work with pulsed X-ray sources as well as continuous wave X-ray sources and gamma sources like Se and Iridium.
In this white paper we explore the usability of the XRpad2 HWx-i DDAs for mobile NDT. We tested the image quality performance at operational temperatures ranging from -20 °C to 50 °C. The XRpad2-i DDAs are evaluated with accordance to the Characterization of Digital Detector Array ASTM E-2597M-14. This standard defines several factors that must be determined to characterize a DDA – we looked the following factors:
• Interpolated basic spatial resolution (iSRb)
• Achievable contrast sensitivity (CSa)
• Image Lag
• Efficiency at 1 mGy
• Specific material thickness (SMTR)
The overall results found in the white paper indicate that the XRpad2 HWx-i detector family, due to its outstanding image quality, fast image acquisition, mobility, and ease of integration is well suited for mobile NDT.