Regd. Office England 2149641 20, Potters Lane, Kiln Farm, Milton Keynes, Buckinghamshire, MK11 3HF, U.K. www.cituk-online.com Tel: +44(01908) 260082 Fax: +44(01908) 260084 e-mail [email protected]Supplier of the World’s Most Advanced Imaging, Digital Radiography, Enterprise Computer and Archive Systems Computerised Information Technology Case Application Note Weld Inspection of 8 mm – 75 mm thickness with Gamma Ir192 Radiation Isotope & Digital Computed Radiography Technology This Case Application report describes the CR – Computed Radiographic Image Quality that meets the requirements of ASME Section VIII Division 1 (UW - 51 & UW – 52), Division 2 (Al-510 & AI-511), ASME Section 1 (PW - 51), ASME B31.1 (136.4.5), EN444 and EN1435 standards. This computed radiographic image quality is achieved by using an Ir192 radiation isotope. The radiographic image quality is assessed by measuring the contrast sensitivity and the radiographic resolution measured with the geometric unsharpness. The results measured are comparable to those achieved with conventional radiography. Selection of radiographic technique and the radiation source depends on various factors such as: • The types of the material that you are inspecting • Thickness of the material • Types of defects, flaws • Radiographic sensitivity required by the referencing code, standards or specifications • The cost of radiography Ir192 is one of the most important sources of energy for use in industrial γ-Radiography for Non Destructive Testing of metals. Due to its high-energy spectra, it is widely used for thick wall inspection (with CR one can inspect up to 100mms of material thickness). With Computed Radiography it has eliminated the requirement for Co60 radiation sources. The Ir192 gamma source characteristics coupled with the source activity controls the overall quality of the radiographic image. Technical details of the source are as follows: Ir192 Isotope Details 192 77 Ir 115 Half life 73.831 d 8 Jπ 4 (+) S π (keV) 6198.08.20 S p (keV) 5729.4.12 Prod. Mode Fast neutron activation Thermal neutron activation ENSDF Citation NDS 84, 717 (1998) Literature cut-off date 1-Aug-1998 Author(s) C. M. Baglin References since cut-off 192 Ir decay from 1998-98 (NSR) Decay Properties Mode Branching (%) Q-value (keV) References β 95.24 4 1459.7 19 88Li06 E 4.76 4 1046.2 23 88Li06 For further details of how CITs Digital Radiography Solutions can help YOUR organisation, please contact us at the address below
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Supplier of the World’s Most Advanced Imaging, Digital Radiography, Enterprise Computer and Archive Systems
Computerised Information Technology
Case Application Note
Weld Inspection of 8 mm – 75 mm thickness with
Gamma Ir192 Radiation Isotope &
Digital Computed Radiography Technology This Case Application report describes the CR – Computed Radiographic Image Quality that meets the requirements of ASME Section VIII Division 1 (UW - 51 & UW – 52), Division 2 (Al-510 & AI-511), ASME Section 1 (PW - 51), ASME B31.1 (136.4.5), EN444 and EN1435 standards. This computed radiographic image quality is achieved by using an Ir192 radiation isotope. The radiographic image quality is assessed by measuring the contrast sensitivity and the radiographic resolution measured with the geometric unsharpness. The results measured are comparable to those achieved with conventional radiography.
Selection of radiographic technique and the radiation source depends on various factors such as: • The types of the material that you are inspecting • Thickness of the material • Types of defects, flaws • Radiographic sensitivity required by the referencing code, standards or specifications • The cost of radiography
Ir192 is one of the most important sources of energy for use in industrial γ-Radiography for Non Destructive Testing of metals. Due to its high-energy spectra, it is widely used for thick wall inspection (with CR one can inspect up to 100mms of material thickness). With Computed Radiography it has eliminated the requirement for Co60 radiation sources.
The Ir192 gamma source characteristics coupled with the source activity controls the overall quality of the radiographic image. Technical details of the source are as follows:
Ir192 Isotope Details
19277 Ir 115
Half life 73.831 d 8 Jπ 4 (+) Sπ(keV) 6198.08.20 Sp(keV) 5729.4.12
Prod. Mode Fast neutron activation Thermal neutron activation
ENSDF Citation NDS 84, 717 (1998) Literature cut-off date 1-Aug-1998 Author(s) C. M. Baglin References since cut-off 192Ir decay from 1998-98 (NSR)
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Ir192 Results and Radiographic Image Mentioned below are the Results (with Radiographic Image and Exposure Parameters) of the Ir192 trials that have been carried out on different thickness of Steel Plate - Weld Samples and the CR Phantom. Note: The Radiographic Images displayed here are only for illustration purpose. The actual images are of high quality and contain more details. CR Phantom - Exposure Parameters & Radiograph Image
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Note: The Radiographic Images displayed here are only for illustration purpose. The actual images are of high quality and contain more details. 14mm Steel Plate - Exposure Parameters & Radiograph Image
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Note: The Radiographic Images displayed here are only for illustration purpose. The actual images are of high quality and contain more details. 38mm Steel Plate - Exposure Parameters & Radiograph Image
From the above results it can be seen that, for the range of plate thicknesses tested, acceptable results are achieved by taking 35% of the calculated D4 exposure time as an exposure, achieving required sensitivity and an equivalent radiographic density of 2.0 to 2.9 in the weld. It is provisionally assumed that this relationship will hold for exposures up to and including 75mm (to inspect greater thickness of material – radiographic techniques need to be developed).