- Email: [email protected]
Laser scanning cameras for in-reactor inspection
17-20 Sep. 1985, pp. 152-155. Proceedings Society for Optical Engineering, Vol. 581
map porosity distribution as well as organic binder/plasticizer distribution through-out the volume of a part. (2) X-ray tomography (both computed and analog) is being developed to map density variations throughout a part volume, as well as to detect defects such as cracks, inclusions, and voids. (3) Low-kV X-ray radiography (including use of microfocus X-ray tubes) with digital image processing is being developed to detect very smafl defects such as inclusions and cracks, as well as some density variations. (4) Ultrasonic methods (backscatter, through-transmission, and pulse-echo) are being developed to detect bulk density differences as weU as inclusions and cracks. The following sections briefly describe recent results obtained with several of these methods.
sachusetts (United States), of SPIE -The International
31655 Maldague, X.; Cielo, P.; Ashley, P.J.; Farahbakhsh, B. Thermographlc NDT of aluminum laminates Canadian Society for Nondestructive Testing Journal, Vol. 8, No. 4, pp. 44, 46-50 (Jul./Aug. 1987) This paper describes and discusses some applications of thermographic imaging to the nondestructive evaluation of aluminum laminates, with particular emphasis on aluminum-to-aluminum and aluminum-to-foam adhesively bonded sheets, Different heating and scanning techniques are described, such as the 2D heating of a stationary panel, line- heating of a laterally-scanned panel, heat-injection and heat-removal methods. The peculiar thermal-propagation properties of such laminates which comprise components having widely different thermal-conductivity values impose some challenging requirements as far as thermal NDT is concerned. These requirements are analysed with the help of finite- difference numerical models to simulate the thermal flow through the different layers. A number of experimental results are presented, and particular emphasis is given to image-processing methods to increase defect visibility.
37112 Link, R.; Nuding, W.; Sauerwein, K.; Souw, E. K. Image processing in real time radiography 11th World Conference on Nondestructive Testing, Las Vegas, Nevada (United States), 3-8 Nov. 1985. Vol. 1, pp. 560-565. Taylor Publishing Co., Dallas (1985). In this paper the possibilities, as well as the different tasks, of image processing in the field of real time radiography will be discussed.
37603 Jehenson, P.S. European developments in radiological methods International Journal of Pressure Vessels and PiDine. . -, Vol. 28. No. l-5, pp. 123-138 (1987) This paper gives an overview of the important current developments in Europe concerning radiological methods for Non-destructive Evaluation (NDE) of materials, including improvements in commercial X- or y- ray techniques (e.g. film radiography), and current advanced X-ray instrumentation (e.g. television fluoroscopy, image processing) as well as new instrumentation (computed tomography, real-time radiography). 37561 Dumont, P.; Bieth, M.; Launay, J. P. French developments in the ultrasonic examination of pressure vessels International Journal of Pressure Vessels and Piping. Vol. 28. No. 1-5. pp. 19-23 (1987) In 1985, thirty four Pressurized Water Reactors (PWRs) were already in service in France and twenty one were being constructed. The manufacturer (Framatome) and the owner (Electricite de France, EDF) have gained great experience in the ultrasonic examination of the various components and particularly of the reactor vessel. The development work initiated concerns improvement of the methods used, the beginning of automation in fabrication control and continuation of the technical implementation of signal and image processing. 37553 Hecht, A.; Neumann, E.; Rose, P. Computer-aided nondestructive ultrasonic testing of ceramic materials High Tech Ceramics. Proceedings of the World Congress on High Tech Ceramics, the 6th International Meeting on Modern Ceramic Technologies (6th CIMTEC), Milan, Italy, 24-28 Jun. 1986. pp. 1169-1178. Edited by P. Vincenzini. Elsevier Science Publishers,
Amsterdam (1987). Even very small defects are detectable by ultrasonic testing techniques. This paper describes the nondestructive ultrasonic testing of some ceramic materials. The ultrasonic results are compared with radiographic testing results by means of a digital image processing system. 31511 Okamura, T.; Sasaki, K.; Mizutani, T.; Shimada, A.; Matsui, M.; M&no, M.; Senoo, M.; Sasaki, M. Techniques of fuel-number imaging with ITV camera and ultrasonic waves for BWR’s loaded fuel subassembly (In Japanese) Journal of the Atomic Energy Society of Japan, Vol. 29, No. 9, pp. 815- 822 (Sep. 1987) An experimental investigation of automatic fuel-number imaging for BWR’s fuel subassemblies has been carried out to reduce the time and the mental load of operators for fuel-number confirmation. The experiments have been conducted for clear imaging with lighting and industrial television camera, and with ultrasonic waves. Following points were clarified: (1) Clear binary-valued character patterns can be obtained by means of sequential two directional lighting and subsequent image processing, and the same lighting technique can be applied to new or old fuel subassemblies, since this technique is based on the geometrical features of the carved characters. (2) Fuel-number images can be obtained by scanning ultrasonic waves on the carved character surface, which is buried in thick cladding mud (such carved characters can be hardly imaged with ITV cameras). 37201 Martin, J. W.; McKnight, M. E.; Bentz, D. P. Thermographic imaging and computer image processing of defects in building materials An International Conference on Thermal Infrared Sensing for Diagnostics and Control (Thermosense VIII), Cambridge, Mas-
NDT International
June 1990
(1986) An image processing system has been coupled to both a thermographic and a video camera to quantify defects from images of building materials. Several applications to building materials are presented including the detection of delaminations in single-ply roofing membrane seams, the characterization of the extent of corrosion under pigmented organic coatings on metallic substrates, the determination of the roughness of a sand-blasted metallic substrate, and the determination of the porosity in hardened cement paste.
36923 Potet, P.; Jeannin, P.; Bath& C. The use of digital image processing in vihrothermographic detection of impact damage in composite materials Materials Evaluation, Vol. 45, No. 4, pp. 466-470 (Apr. 1987) Some applications of digital image processing in vibrothermographic detection of impact damage in composite materials are described. Heat transfer mechanisms in composite laminates are outlined. Basic image- processing functions feature soatial fiherina. temwral averaaina. and image subtraction. A specific image-processing funcgon, the resolution-of the bidimensional heat transfer equation, is described. Some vibrothermograms processed with the image-processing program are also presented. 36907 Batchelor, B.C.; Hill, D.A.; Hodgson, D.C. (ea’s.) Automated visual inspection IFS (Publications) Ltd., 561 pp. (1985) This book discusses the automation of inspection with light and its application to a wide range of problems in many different industries. The various chapters include: optics for image sensors; image acquisition; lighting and viewing techniques; coherent optical techniques; television techniques; solid state image sensors; flying spot laser scanners; fibre-optic sensors; principles of digital image processing: microprocessor-based visual inspection; and the INTELLECT image processing system. 36766
Adrain, R.S.; Armour,
I.A.;
Bach, J. H.
Laser scanning cameras for in-reactor inspection Sensor Review, Vol. 7, No. 2, pp. 68-76 (Apr. 1987) Laser scanning cameras have been developed for various inspection jobs in nuclear reactors. These cameras have large depth of field and resolution of approx. 0.16m rad and in some of the designs for AGR use, large angular coverages can be obtained e.g., 360 deg by 100 deg. Zoom ratios of about 20 can be achieved on and off axis. Using these highly sensitive cameras, objects at ranges of up to 16m can be inspected with high contrast. Since the cameras have S-bits contrast, a greater range of contrasting scenes can be viewed than in conventional television cameras. In practice they have proved robust, simple to use and insensitive to radiation. Also, in the case of the AGR laser scanning cameras, the digital picture is ideal for digital archival storage or image processins.
36645 Abdul-Razzak, M. M.; Hardwick, B.A.; Hey-Shipton, G.L.; Matthews, P.A.; Monson, J. R. T.; Kester, R. C. Microwave thermography for medical applications IEE Proceedings, Vol. 134, Pt. A, No. 2, pp. 171-174 (Feb. 1987) A scanning microwave thermograph has been built, operating in the band 9-10 GHz, which produces a video display of the variations in the emission temperature of the human body. Image processing is incorporated in the instrument to reduce the effects of noise and antenna smoothing and also to assist in image analysis. Preliminary medical studies on a number of patients suffering from occlusive vascular disease of the lower limbs have shown that the instrument both confirms medical diagnosis made by conventional techniques and improves assessment of tissue blood flow. The technique is fast, noninvasive and passive. The instrument is self-contained and can be used wherever convenient in clinics. 36641 Moore, F.W. Remote visual inspection video image processing
of nuclear fuel pellets with Rher optics and
Optical Engineering, Vol. 26, No. 2, pp. 152-155 (Feb. 1987) Westinghouse Hanford Company has designed and constructed a nuclear fuel fabrication process line for the U.S. Department of Energy. This process line includes a system that remotely inspects the cylindrical surface of nuclear fuel pellets for surface spots, flaws, or discoloration. The pellets are inspected on a 100% basis after pellet sintering. A feeder delivers the pellets directly to a fiber optic inspection head, which views one pellet surface at a time and images it to a closed-circuit colour television camera (CCTV). The output signal of the CCTV is input to a digital imaging processor that stores approximately 25 pellet images at a time. A human operator visually examines the images of the pellet surfaces on a hiah resolution monitor and accepts or reiects the oellets based on visual standards. The operator uses a digitizing tablet to record the location of rejected pellets, which are then automatically removed from the product stream. The system is expandable to automated disposition of the pellet surface image.
175
map porosity distribution as well as organic binder/plasticizer distribution through-out the volume of a part. (2) X-ray tomography (both computed and analog) is being developed to map density variations throughout a part volume, as well as to detect defects such as cracks, inclusions, and voids. (3) Low-kV X-ray radiography (including use of microfocus X-ray tubes) with digital image processing is being developed to detect very smafl defects such as inclusions and cracks, as well as some density variations. (4) Ultrasonic methods (backscatter, through-transmission, and pulse-echo) are being developed to detect bulk density differences as weU as inclusions and cracks. The following sections briefly describe recent results obtained with several of these methods.
sachusetts (United States), of SPIE -The International
31655 Maldague, X.; Cielo, P.; Ashley, P.J.; Farahbakhsh, B. Thermographlc NDT of aluminum laminates Canadian Society for Nondestructive Testing Journal, Vol. 8, No. 4, pp. 44, 46-50 (Jul./Aug. 1987) This paper describes and discusses some applications of thermographic imaging to the nondestructive evaluation of aluminum laminates, with particular emphasis on aluminum-to-aluminum and aluminum-to-foam adhesively bonded sheets, Different heating and scanning techniques are described, such as the 2D heating of a stationary panel, line- heating of a laterally-scanned panel, heat-injection and heat-removal methods. The peculiar thermal-propagation properties of such laminates which comprise components having widely different thermal-conductivity values impose some challenging requirements as far as thermal NDT is concerned. These requirements are analysed with the help of finite- difference numerical models to simulate the thermal flow through the different layers. A number of experimental results are presented, and particular emphasis is given to image-processing methods to increase defect visibility.
37112 Link, R.; Nuding, W.; Sauerwein, K.; Souw, E. K. Image processing in real time radiography 11th World Conference on Nondestructive Testing, Las Vegas, Nevada (United States), 3-8 Nov. 1985. Vol. 1, pp. 560-565. Taylor Publishing Co., Dallas (1985). In this paper the possibilities, as well as the different tasks, of image processing in the field of real time radiography will be discussed.
37603 Jehenson, P.S. European developments in radiological methods International Journal of Pressure Vessels and PiDine. . -, Vol. 28. No. l-5, pp. 123-138 (1987) This paper gives an overview of the important current developments in Europe concerning radiological methods for Non-destructive Evaluation (NDE) of materials, including improvements in commercial X- or y- ray techniques (e.g. film radiography), and current advanced X-ray instrumentation (e.g. television fluoroscopy, image processing) as well as new instrumentation (computed tomography, real-time radiography). 37561 Dumont, P.; Bieth, M.; Launay, J. P. French developments in the ultrasonic examination of pressure vessels International Journal of Pressure Vessels and Piping. Vol. 28. No. 1-5. pp. 19-23 (1987) In 1985, thirty four Pressurized Water Reactors (PWRs) were already in service in France and twenty one were being constructed. The manufacturer (Framatome) and the owner (Electricite de France, EDF) have gained great experience in the ultrasonic examination of the various components and particularly of the reactor vessel. The development work initiated concerns improvement of the methods used, the beginning of automation in fabrication control and continuation of the technical implementation of signal and image processing. 37553 Hecht, A.; Neumann, E.; Rose, P. Computer-aided nondestructive ultrasonic testing of ceramic materials High Tech Ceramics. Proceedings of the World Congress on High Tech Ceramics, the 6th International Meeting on Modern Ceramic Technologies (6th CIMTEC), Milan, Italy, 24-28 Jun. 1986. pp. 1169-1178. Edited by P. Vincenzini. Elsevier Science Publishers,
Amsterdam (1987). Even very small defects are detectable by ultrasonic testing techniques. This paper describes the nondestructive ultrasonic testing of some ceramic materials. The ultrasonic results are compared with radiographic testing results by means of a digital image processing system. 31511 Okamura, T.; Sasaki, K.; Mizutani, T.; Shimada, A.; Matsui, M.; M&no, M.; Senoo, M.; Sasaki, M. Techniques of fuel-number imaging with ITV camera and ultrasonic waves for BWR’s loaded fuel subassembly (In Japanese) Journal of the Atomic Energy Society of Japan, Vol. 29, No. 9, pp. 815- 822 (Sep. 1987) An experimental investigation of automatic fuel-number imaging for BWR’s fuel subassemblies has been carried out to reduce the time and the mental load of operators for fuel-number confirmation. The experiments have been conducted for clear imaging with lighting and industrial television camera, and with ultrasonic waves. Following points were clarified: (1) Clear binary-valued character patterns can be obtained by means of sequential two directional lighting and subsequent image processing, and the same lighting technique can be applied to new or old fuel subassemblies, since this technique is based on the geometrical features of the carved characters. (2) Fuel-number images can be obtained by scanning ultrasonic waves on the carved character surface, which is buried in thick cladding mud (such carved characters can be hardly imaged with ITV cameras). 37201 Martin, J. W.; McKnight, M. E.; Bentz, D. P. Thermographic imaging and computer image processing of defects in building materials An International Conference on Thermal Infrared Sensing for Diagnostics and Control (Thermosense VIII), Cambridge, Mas-
NDT International
June 1990
(1986) An image processing system has been coupled to both a thermographic and a video camera to quantify defects from images of building materials. Several applications to building materials are presented including the detection of delaminations in single-ply roofing membrane seams, the characterization of the extent of corrosion under pigmented organic coatings on metallic substrates, the determination of the roughness of a sand-blasted metallic substrate, and the determination of the porosity in hardened cement paste.
36923 Potet, P.; Jeannin, P.; Bath& C. The use of digital image processing in vihrothermographic detection of impact damage in composite materials Materials Evaluation, Vol. 45, No. 4, pp. 466-470 (Apr. 1987) Some applications of digital image processing in vibrothermographic detection of impact damage in composite materials are described. Heat transfer mechanisms in composite laminates are outlined. Basic image- processing functions feature soatial fiherina. temwral averaaina. and image subtraction. A specific image-processing funcgon, the resolution-of the bidimensional heat transfer equation, is described. Some vibrothermograms processed with the image-processing program are also presented. 36907 Batchelor, B.C.; Hill, D.A.; Hodgson, D.C. (ea’s.) Automated visual inspection IFS (Publications) Ltd., 561 pp. (1985) This book discusses the automation of inspection with light and its application to a wide range of problems in many different industries. The various chapters include: optics for image sensors; image acquisition; lighting and viewing techniques; coherent optical techniques; television techniques; solid state image sensors; flying spot laser scanners; fibre-optic sensors; principles of digital image processing: microprocessor-based visual inspection; and the INTELLECT image processing system. 36766
Adrain, R.S.; Armour,
I.A.;
Bach, J. H.
Laser scanning cameras for in-reactor inspection Sensor Review, Vol. 7, No. 2, pp. 68-76 (Apr. 1987) Laser scanning cameras have been developed for various inspection jobs in nuclear reactors. These cameras have large depth of field and resolution of approx. 0.16m rad and in some of the designs for AGR use, large angular coverages can be obtained e.g., 360 deg by 100 deg. Zoom ratios of about 20 can be achieved on and off axis. Using these highly sensitive cameras, objects at ranges of up to 16m can be inspected with high contrast. Since the cameras have S-bits contrast, a greater range of contrasting scenes can be viewed than in conventional television cameras. In practice they have proved robust, simple to use and insensitive to radiation. Also, in the case of the AGR laser scanning cameras, the digital picture is ideal for digital archival storage or image processins.
36645 Abdul-Razzak, M. M.; Hardwick, B.A.; Hey-Shipton, G.L.; Matthews, P.A.; Monson, J. R. T.; Kester, R. C. Microwave thermography for medical applications IEE Proceedings, Vol. 134, Pt. A, No. 2, pp. 171-174 (Feb. 1987) A scanning microwave thermograph has been built, operating in the band 9-10 GHz, which produces a video display of the variations in the emission temperature of the human body. Image processing is incorporated in the instrument to reduce the effects of noise and antenna smoothing and also to assist in image analysis. Preliminary medical studies on a number of patients suffering from occlusive vascular disease of the lower limbs have shown that the instrument both confirms medical diagnosis made by conventional techniques and improves assessment of tissue blood flow. The technique is fast, noninvasive and passive. The instrument is self-contained and can be used wherever convenient in clinics. 36641 Moore, F.W. Remote visual inspection video image processing
of nuclear fuel pellets with Rher optics and
Optical Engineering, Vol. 26, No. 2, pp. 152-155 (Feb. 1987) Westinghouse Hanford Company has designed and constructed a nuclear fuel fabrication process line for the U.S. Department of Energy. This process line includes a system that remotely inspects the cylindrical surface of nuclear fuel pellets for surface spots, flaws, or discoloration. The pellets are inspected on a 100% basis after pellet sintering. A feeder delivers the pellets directly to a fiber optic inspection head, which views one pellet surface at a time and images it to a closed-circuit colour television camera (CCTV). The output signal of the CCTV is input to a digital imaging processor that stores approximately 25 pellet images at a time. A human operator visually examines the images of the pellet surfaces on a hiah resolution monitor and accepts or reiects the oellets based on visual standards. The operator uses a digitizing tablet to record the location of rejected pellets, which are then automatically removed from the product stream. The system is expandable to automated disposition of the pellet surface image.
175