Original scientific paper

Contrast gradient determination in digital radiography to optimize the capability in defect detection

Enkelejda Sotja ; Mechanical Department, Polytechnic University of Tirana, Tirane, Albania
Dhimitraq Sotja ; Mechanical Department, Polytechnic University of Tirana, Tirane, Albania
Giuseppe Nardoni ; I&T Nardoni Institute S.R.L., Brescia, Italy
Pietro Nardoni ; I&T Nardoni Institute S.R.L., Brescia, Italy

Abstract

Digital radiography is a growing technique in X-ray examinations. It is the aim of the present work to study the main parameters that affect the quality of image in terms of contrast and definitions. A number of tests have been carried out on a calibrated stepped wedge exposed to different levels of energy and related time. The range of thickness involved has been between 5 and 20 mm. The steps' change value has been between 0,2 and 1 mm. Two fundamental diagrams have been traced after the experimental tests: grey level/relative exposure relation and contrast gradient/ grey level relation. Another important thing has been taken into consideration during the test; changes of hundreds of millimetres (mm) in wire diameter can cause a level of sensitivity higher than 2 % which is, consequently, not accepted by the code. This change, in our opinion has no effective impacts on the detection of defects such, lack of penetration, porosity, cracks and slag inclusion.

Keywords

contrast; digital radiography; quality of image

Hrčak ID:

69580

URI

https://hrcak.srce.hr/69580

Publication date:

27.6.2011.

Article data in other languages: croatian

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