This standard (Part 1) specifies the method for radiographic examination of fusion welded butt joints in steel plates up to 50 mm thick. It details the requirements for radiographic techniques, equipment, image quality indicators (IQIs), and film processing to ensure the production of satisfactory radiographs for interpretation.
Specifies the method for radiographic examination of fusion welded butt joints in steel plates.
Quick Reference Values
Minimum film density (single film)1.5 H&D
Preferred film density (single film)2.0 H&D
Maximum allowable geometric unsharpness (Ug) for thickness up to 50 mm0.5 mm
Required IQI sensitivity for critical applications2% of specimen thickness
Minimum source-to-film distanceGenerally 7 times the specimen thickness
Key Formulas
Ug = f * t / D — Geometric Unsharpness (f=source size, t=thickness, D=source-to-object distance)
Practical Notes
This is a 'method' standard; acceptance criteria for weld defects are typically found in other codes like IS 1182 or project-specific documents.
Proper selection between X-rays and Gamma-rays is crucial. X-rays provide better contrast on thinner sections, while portable Gamma-ray sources are often used for site work and thicker materials.
Image Quality Indicator (IQI) placement is critical for validating the sensitivity of the radiograph. It should typically be placed on the source side.