TY - CONF A1 - Ewert, Uwe A1 - Zscherpel, Uwe T1 - Aktuelle Entwicklungen in der Normung N2 - Es wird über die neuen Anforderungen ausgewählter Normen bzw. Normrevisionen informiert und insbesondere auch über die veränderten Parameter, die bei der Prüfpraxis, der Qualitätssicherung in der digitalen Radiographie und bei der Klassifizierung zu berücksichtigen sind. Das wichtigste Projekt ist die Revision der DIN EN ISO 17636-1, -2, RT von Schweißverbindungen, in ISO TC 44 SC 5 WG 1. Hauptaktivität bei ASTM ist gegenwärtig die Überarbeitung der CT-Standards und die Berücksichtigung der Anforderungen an das dimensionelle Messen. Der „Standard Guide for Computed Tomography“, ASTM E 1441, zur Bestimmung von MTF, Kontrast-Detail-Funktion (CDF) und Kontrast-Diskrimination-Diagramm (CDD) wurde revidiert und veröffentlicht. Die Mehrzahl der Hersteller von CT-Anlagen bietet entsprechende Software-Tools an. Weiterhin werden neue Festkörperentwürfe zur Charakterisierung von CT-Anlagen vorgestellt. Die folgenden Revisionen sind bei ASTM derzeit in Bearbeitung: ASTM E 2445, „CR Long Term Stability“ nach einem Round Robin-Test und für DDAs der Standard zur System-Charakterisierung, ASTM E2597/E2597M−14, und zur „DDA Long Term Stability“. Das Spider-Net-Diagramm zur Klassifizierung von DDAs wird um die Position „ISO Material Thickness limit“ erweitert. Der Standard EN 12679 zur Messung der Größe von Gammastrahlern wurde nach Revision unter Berücksichtigung von digitalen Messverfahren veröffentlicht. Die Revision der Standardserie EN 12543 zur Messung der Brennfleckgröße ist mit Verzögerung in Überarbeitung, um die digitalen Detektoren und Messmöglichkeiten mit Bildverarbeitungsprogrammen zu berücksichtigen. Die Messprozedur für Lochkameras wurde grundlegend revidiert und ist harmonisiert mit ASTM E 1165-12(2017). Die gemessenen Brennflecke unterscheiden sich und passen besser zu den Unschärfe-Messungen mit Doppeldraht BPKs (ISO 19232-5:2018) bei Vergrößerung. Ein Entwurf zur Messung der Brennfleckgröße von nano-Fokusröhren und Mikro-Fokusröhren (< 5 µm) wird derzeit vom Europäischen Metrologie-Programm EMPIR gefördert. Es wird über erste Ergebnisse informiert. T2 - 19. Seminar Aktuelle Fragen der Durchstrahlungsprüfung und Strahlenschutz CY - Online meeting DA - 23.03.2021 KW - Industrielle Durchstrahlungsprüfung KW - ZfP KW - Normentwicklung RT KW - DIN ISO ASTM International PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-524149 SP - Paper 8, 1 EP - Paper 8, 15 PB - DGZfP AN - OPUS4-52414 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Silva, W. A1 - Lopes, R. A1 - Zscherpel, Uwe A1 - Meinel, Dietmar A1 - Ewert, Uwe T1 - X-ray imaging techniques for inspection of composite pipelines N2 - The literature has shown that the application of laminography provides advantages as 3D radiographic imaging with depth information for in house and mobile testing. This permits to distinguish between overlapping indications, measure the extension along radiation direction and classify indications as surface open or subsurface ones as required in critical engineering assessment. This work provides a comparative study and measurements of the three techniques Digital Radiography (DR) with Digital Detector Arrays (DDA), Coplanar Translational Laminography (CTL) and Computed Tomography (CT), applied for composite pipeline inspection. It is demonstrated that CTL and CT provide advantages for the evaluation of pipe-to-pipe connections and the evaluation of adhesive applications. They show indications of discontinuities with higher contrast sensitivity than radiography. Beyond it, two specimen, namely Phantom 1 and Phantom 2, were developed and manufactured by additive manufacturing to analyze the preferential detection sensitivity and the direction of features and depth information for laminographic measurements. Another goal was to show the laminographic capabilities to distinguish between overlapping discontinuities. CTL is especially suitable for mobile inspection. Special glass fiber reinforced polymer samples (GRP) were manufactured for further analysis and comparisons between the abovementioned techniques. Finally, Phantoms 1 and 2 show the capability of laminography to detect overlapping indications and also show that discontinuities oriented perpendicular to the scan direction have the highest contrast sensitivity for laminographic measurements. KW - Digital Radiography KW - Laminography KW - Computed Tomography KW - Composite Pipes KW - Image Quality PY - 2021 DO - https://doi.org/10.1016/j.micron.2021.103033 SN - 0968-4328 VL - 145 SP - 103033 PB - Elsevier Ltd. AN - OPUS4-52415 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zscherpel, Uwe A1 - Ewert, Uwe T1 - Electronic reference images for flaw indications in welds and castings N2 - Since decades the evaluation of flaw indications on radiographs from welds or castings are based on well accepted reference film catalogues from organizations like IIW (weldments), ASTM (castings) or DGZfP (D5 recommendation on heavy steel castings). Today, the transformation of classical film radiography to the digital world is in full progress. Some ASTM standards do not permit the evaluation of digital radiographs in reference to film catalogues. Therefore, these reference film catalogues have to be converted into the digital age too. BAM is supporting this transition by high definition film scanning. The result is a corresponding reference image catalogue. The different standard organizations selected different ways to distribute the digital data. ASTM used high definition film scanning at 10 μm pixel size and distribution of a huge amount of high-res data via DVD. The user sub-samples these high-res data during catalogue import to the resolution of his system. The comparison is done by synchronized image viewing on the computer work station. IIW recently decided to distribute their ISO 5817 reference images installed on tablets, which are used for image viewing too. The tablet image has to be compared with the digital image on the system monitor. DGZfP transformed their D5 reference radiographs into a PDF for monitor viewing. This is the simplest and cheapest solution, but still allows the full usage of the catalogue in the digital era. The status of ongoing work in progress will be discussed. T2 - WCNDT 2016 CY - Munich, Germany DA - 13.06.2016 KW - Castings KW - NDT KW - RT KW - Radiography KW - Discontinuities KW - Catalogues KW - Welds PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-377306 UR - http://ndt.net/?id=19310 SN - 1435-4934 VL - 21 IS - 7 SP - 1 EP - 8 PB - NDT.net CY - Kirchwald AN - OPUS4-37730 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zscherpel, Uwe A1 - Ewert, Uwe T1 - Filmersatz in der radiographischen Schweißnahtprüfung: Neue ISO-Standards und Erfahrungen im praktischen Einsatz digitaler Detektoren N2 - Der Ersatz von Röntgenfilmen durch digitale Detektoren in der zerstörungsfreien Prüfung wurde in den letzten 10 Jahren kontrovers diskutiert. Nach der Erfolgsgeschichte der digitalen Photographie und der fast vollständigen Ablösung der Filmtechnik in der optischen Bilderfassung wurde erwartet, dass sich der Übergang von der Filmradiographie zur digitalen Radiographie schnell vollziehen sollte. Dieser Trend ist derzeit so noch nicht zu beobachten. Zur mobilen Prüfung wird in Europa immer noch vorrangig die Filmradiographie und nur teilweise die Speicherfolientechnik eingesetzt. Im Bereich der stationären Prüftechnik haben sich die Matrixdetektoren (DDA) weitgehend durchgesetzt, wobei es auch hier noch alternative Detektoren wie Bildverstärker und Fluoroskope gibt. Mit Einführung der DIN EN ISO 17636-2 wird seit 2013 erstmalig geregelt, wie man einen digitalen Detektor für die technische Radiographie auswählen soll, um im Vergleich zur Filmradiographie eine äquivalente Bildqualität zu erhalten. Essentielle Parameter bestimmen, ob die geforderte Bildgüte erreicht werden kann. Es wird ein Überblick gegeben, welche Parameter zum praktischen Einsatz wichtig sind und wie sie ermittelt werden. Erste Erfahrungen im praktischen Einsatz werden diskutiert. T2 - Sondertagung "Schweissen im Anlagen- und Behälterbau" 2016 CY - Munich, Germany DA - 23.02.2016 KW - Welds KW - RT KW - Radiography KW - NDT KW - Discontinuities KW - Catalogues KW - Zerstörungsfreie Prüfung KW - Praktische Erfahrungen KW - Standardisierung KW - Durchstrahlungsprüfung KW - Filmersatz durch digitale Detektoren PY - 2016 SN - 978-3-945023-59-4 VL - 322 SP - 55 EP - 58 PB - DVS Media CY - Düsseldorf AN - OPUS4-37733 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Zscherpel, Uwe A1 - Ewert, Uwe ED - Russo, Paolo T1 - Handbook of X-ray imaging: Physics and technology N2 - Industrial Radiology is used for volumetric inspection of industrial objects. By penetration of these objects (typically weldments, pipes or castings) with X-ray or Gamma radiation the 3D-volume is projected onto a 2D image detector. The X-ray film is the oldest radiographic image detector and still in wide use in industry. The industrial X-ray film systems used today differ from these used in medicine. Medical film systems are described well in the literature, but industrial film systems not. So we start with a description of the properties and standards for industrial film systems. The requirements on image quality are defined by several standards and can be verified with different image quality indicators (IQIs). They describe the ability of the human being to detect small and low contrast indications in a noisy image background. The essential parameters for digital industrial radiology are described. Since about 30 years electronic image detectors are gradually replacing the industrial film. These detectors are based on storage phosphor imaging plates in combination with Laser scanners (“Computed Radiography”, CR) or a variety of different digital detector arrays (DDA). Typical applications of CR and DDAs are discussed as well as new possibilities by digital image processing, which is enabled by the computer based image handling, processing and analysis. KW - Industrial radiology KW - Industrial radiography KW - NDT films KW - Computed radiography KW - Digital detector arrays PY - 2018 SN - 978-1-4987-4152-1 SP - Chapter 30, 595 EP - 617 PB - CRC Press CY - Boca Raton, FL, USA AN - OPUS4-44026 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ewert, Uwe A1 - Zscherpel, Uwe A1 - Vogel, Justus A1 - Zhang, F. A1 - Long, N.X. A1 - Nguyen, T.P. T1 - Visibility of Image Quality Indicators (IQI) by Human Observers in Digital Radiography in Dependence on Measured MTFs and Noise Power Spectra N2 - Digital radiographic images were analysed to predict the visibility of image quality indicators (IQI), based on normalized noise power spectra (NNPP) and modulation transfer function (MTF) measurements. The fixed pattern noise of some digital detectors result in different noise spectra, which influence the visibility of different IQIs, depending on the hole diameter. Studies, based on measurement of basic spatial resolution and contrast to noise ratio were performed together with presampled MTF measurements and the NNPS in dependence on the spatial frequency. Plate hole IQIs, step hole IQIs, and equivalent penetrameter sensitivity (EPS) IQIs based on ASTM E 746 were measured to verify the influence of the different parameters. Modelling of digital images was used to verify the applied numeric tools. A study has been performed for imaging plates and digital detector arrays to analyse differences. Formulas for the prediction of the visibility functions for hole type IQIs are derived. In consequence the standards for characterization and classification of computed radiography (ASTM E 2446) and radiography with DDAs (ASTM E 2597) need to be revised. T2 - 12th ECNDT 2018 CY - Gothenburg, Sweden DA - 11.06.2018 KW - Image evaluation KW - Computed radiography (CR) KW - Digital Detector Array (DDA) KW - Detail detection PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-473486 UR - www.ndt.net/?id=22967 SN - 1435-4934 VL - 23 IS - 8 SP - 1 EP - 7 PB - NDT.net CY - Kirchwald AN - OPUS4-47348 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ewert, Uwe A1 - Zscherpel, Uwe A1 - Zhang, F. A1 - Long, N.X. A1 - Phong, N. T1 - Essentielle Parameter zur numerischen Abschätzung der Sichtbarkeit von Bildgüteprüfkörpern in der digitalen Radiographie N2 - Die Voraussetzungen für die Vorhersage der Sichtbarkeit von Bildgüteprüfkörpern (BPK) wurden seit Beginn der kommerziellen Anwendung der technischen Radiographie diskutiert und in diversen nationalen und internationalen Standards festgeschrieben. Diese Fragen werden nach Einführung der digitalen Radiographie und der CT wieder neu diskutiert. Draht BPKs wurden in Deutschland seit 1935 (DIN 1915: 1935) und später in den meisten europäischen Ländern benutzt. In den USA und Frankreich wurden vorzugsweise BPKs mit Löchern verwendet (ASTM E 1025 seit 1984 oder E 1742 seit 1992 bzw. die Vorgängernorm MIL STD-543 seit 1962). Jetzt werden auch die Umrechnungsnormen zur Erkennbarkeit von Draht zu Loch-BPKs in Frage gestellt. ISO 19232-3, der französische RCCM-Kode einerseits und ASTM E 747 und ASME BPVC Section V Tab. T-276 andererseits unterscheiden sich erheblich bei den Anforderungen im Bereich hoher Wandstärken (Hochenergieradiographie). Untersuchungen dazu werden vorgestellt. Mit Einführung der digitalen Detektoren ändern sich auch die Rauschspektren. Durch die Herstellung werden insbesondere bei Speicherfolien "Rauschmuster" eingeprägt, die bei hohen Belichtungsdosen sichtbar werden. Diese veränderten Rauschspektren ergeben auch veränderte Erkennungsparameter für menschliche Bildauswerter. Hierzu wurden an ausgewählten Detektoren MTFs (presampled) und normierte Rauschspektren gemessen. Erweiterte Erkennbarkeits-Formeln zur Vorhersage der Sichtbarkeit von BPKs für Bildauswerter und erste Ergebnisse werden vorgestellt. T2 - DGZfP-Jahrestagung 2018 CY - Leipzig, Germany DA - 07.05.2018 KW - Image quality KW - Computed radiography (CR) KW - Digital Detector Array (DDA), KW - Sichtbarkeit von Anzeigen PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-473496 UR - www.ndt.net/?id=23069 VL - 2018 SP - 1 EP - 14 PB - Deutsche Gesellschaft für zerstörungsfreie Prüfung e.V. (DGZfP) AN - OPUS4-47349 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schumacher, David A1 - Zscherpel, Uwe A1 - Ewert, Uwe T1 - Recent developments of photon counting and energy discriminating detectors for radiographic imaging N2 - The direct detection of X-ray photons into electrical signals is enabled by usage of highly absorbing photo conducting materials (e.g. CdTe) as detection layer of an underlying CMOS semiconductor X-ray image detector. If the read-out speed is high enough (ca. 50 - 100 ns dead time) single X-ray photons can be counted and their energy measured. Read-out noise and dark image correction can be diminished. By setting energy thresholds, selected energy ranges of the X-ray spectrum can be detected or suppressed. This allows material discrimination or reduction of scattered radiation, which results in an enhanced contrast sensitivity. T2 - Far East NDT New Technology & Application Forum (FENDT) CY - Xi'an, China DA - 22.06.2017 KW - Industrial X-ray imaging KW - Photon counting KW - Energy discrimination KW - Dual energy imaging KW - Direct detection PY - 2018 UR - https://ieeexplore.ieee.org/document/8584559 SN - 978-1-5386-1615-4 DO - https://doi.org/10.1109/FENDT.2017.8584559 VL - 2017 SP - 281 EP - 285 PB - IEEE Xplore AN - OPUS4-47175 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zscherpel, Uwe A1 - Ewert, Uwe A1 - Jechow, Mirko ED - Thompson, D. O. ED - Chimenti, D. E. T1 - Concepts for evaluation of image quality in digital radiology N2 - Concepts for digital image evaluation are presented for Computed Radiography (CR) and Digital Detector Arrays (DDAs) used for weld inspection. The precise DDA calibration yields an extra ordinary increase of contrast sensitivity up to 10 times in relation to film radiography. Restrictions in spatial resolution caused by pixel size of the DDA are compensated by increased contrast sensitivity. First CR standards were published in 2005 to support the application of phosphor imaging plates in lieu of X-ray film, but they need already a revision based on experiences reported by many users. One of the key concepts is the usage of signal-to-noise (SNR) measurements as equivalent to the optical density of film and film system class. The contrast sensitivity, measured by IQI visibility, depends on three essential parameters: The basic spatial resolution (SRb) of the radiographic image, the achieved signal-to-noise ratio (SNR) and the specific contrast (µeff - effective attenuation coefficient). Knowing these 3 parameters for the given exposure condition, inspected material and monitor viewing condition permits the calculation of the just visible IQI element. Furthermore, this enables the optimization of exposure conditions. The new ISO/FDIS 17636-2 describes the practice for digital radiography with CR and DDAs. It considers the first time compensation principles, derived from the three essential parameters. The consequences are described. T2 - 38th Annual Review of Progress in Quantitative Nondestructive Evaluation CY - Burlington, VT, USA DA - 17.07.2011 KW - Image resolution KW - Inspection KW - Production engineering computing KW - Radiography KW - Welding KW - X-ray imaging KW - ZfP KW - Radiographie KW - Bildqualität KW - Filmersatz KW - Digitale Detektoren PY - 2012 SN - 978-0-7354-1013-8 DO - https://doi.org/10.1063/1.4716281 SN - 0743-0760 SN - 0094-243X N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings IS - 1430 SP - 589 EP - 596 PB - American Institute of Physics CY - Melville, NY AN - OPUS4-26697 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kolkoori, Sanjeevareddy A1 - Wrobel, Norma A1 - Zscherpel, Uwe A1 - Ewert, Uwe T1 - A new X-ray backscatter imaging technique for non-destructive testing of aerospace materials N2 - This paper presents a new X-ray backscatter technique (XBT) for non-destructive imaging of aerospace materials with only a single-sided access. It uses a special twisted slit collimator to inspect the whole object by changing the viewing direction of the X-ray backscatter camera. For the first time, the X-ray backscatter measurements were conducted using high-energy (>500 keV) X-ray sources. Experiments were performed on thick complex structured aluminium components, stringers and honeycomb structures to validate the applicability of the present technique to image small changes in the material properties and also to detect low-density material inclusions. In order to reduce the inspection time from hours to several seconds and to improve the image quality of the X-ray backscatter image, the backscattered signals were measured using a digital detector array with high spatial resolution (200 µm). The influence of the energy of the X-ray source and the slit width of the camera on the X-ray backscatter image were also investigated. In the proposed technique, the whole object is irradiated by an un-collimated X-ray beam resulting in a low image acquisition time of 3 min that facilitates the use of XBT for the real time NDT&E of aerospace materials. KW - X-ray backscatter imaging KW - Digital radiography KW - Digital detector array KW - Non-destructive evaluation KW - Aerospace applications PY - 2015 DO - https://doi.org/10.1016/j.ndteint.2014.09.008 SN - 0963-8695 VL - 70 SP - 41 EP - 52 PB - Butterworth-Heinemann CY - Oxford AN - OPUS4-32515 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ewert, Uwe A1 - Zscherpel, Uwe T1 - Minimum requirements for digital radiography equipment and measurement procedures by different industries and standard organizations N2 - The digital photography has almost completely substituted the film photography. The film replacement is also fast progressing in medical X-ray radiography. This process is slower in NDT and especially in Europe. Reasons for the hesitating change to digital radiography (RT-D) in NDT are the necessary time for adoption of standards and the conservative request for film RT by auditors and NDT managers for applications in large plants and at construction areas. The fast serial inspection for small castings is already almost completely dominated by RT-D due to the cost effective short exposure and interpretation times. Standards were developed in parallel at CEN, ISO, ASTM and ASME. Unfortunately, the standard practices are different and the requirements on image quality and useable hardware are different too. The first standard series on Computed Radiography were developed and published by CEN and ASTM in 2005. Harmonized classification and qualification standards are available but the published practices are different. ASTM has developed the first standards for application of Digital Detector Arrays (DDA) in 2010. The first digital RT ISO standard practice is ISO 17636-2 (2013), which describes the practice for application of DDAs and Imaging Plates for weld inspection. At the first time this standard provides requirements for the selection of suitable hardware. Minimum image quality requirements are specified in analogy to film radiography and 3 Compensation Principles are defined to enable the application of a wider range of digital detectors. A comparison of the different international digital RT standards is given and first experiences with ISO 17636-2 are discussed. New standards on RT wall thickness and corrosion measurements (EN 16407, film and digital) have been developed recently. T2 - ECNDT 2014 - 11th European conference on non-destructive testing CY - Prague, Czech Republic DA - 06.10.2014 KW - NDT KW - X-Ray KW - Digital detectors KW - Standards KW - Radiographic procedures KW - Unsharpness KW - Basic spatial resolution KW - Requirements KW - Digital industrial radiology PY - 2014 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-323081 UR - https://www.ndt.net/?id=16708 SN - 1435-4934 VL - 19 IS - 12 SP - 1 EP - 18 PB - NDT.net CY - Kirchwald AN - OPUS4-32308 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Osterloh, Kurt A1 - Rädel, Christoph A1 - Zscherpel, Uwe A1 - Meinel, Dietmar A1 - Ewert, Uwe A1 - Buecherl, T. A1 - Hasenstab, A. T1 - Fast neutron radiography and tomography of wood N2 - Wood is the material that has accompanied the whole development of mankind in various applications, for manufacturing tools and weapons, for buildings and constructions and also as fuel. It has various appearances and is subjected to decomposing changes, so there are sufficient arguments for non-destructive testing of wooden objects in the same way as is common practice with other technologically used materials. However, even today wood is rarely tested. Moreover, artefacts of cultural heritage containing wood are rare and delicate, so dismantling these for studying purposes is undesirable. Radiological inspection technologies are the methods of choice to provide a non-destructive insight. Interrogations of a specimen with various kinds of radiation provide different answers about their internal structures. High-quality detailed images are achievable with X-rays or gamma radiation in cases where heavy metals or other dense materials are not involved. Neutrons behave complementarily; they are avidly absorbed by light elements such as hydrogen on the one hand and yet are capable of easily penetrating heavy metals on the other. This provides an alternative for X-ray radiography and tomography when material characteristics are of primary interest rather than structural details, or when shielding with plates or sleeves of heavy metal severely impedes inspections with X-ray or gamma radiation technologies. However, due to the moderating effect of wooden samples it is essential to use fast neutrons for radiography and tomography of voluminous objects. Some typical examples described here will show the difference between neutron and X-ray photon-based radiographic technologies. KW - Materialgeschichtliches KW - Vergleich zwischen Röntgen- und Neutronenradiographie PY - 2008 DO - https://doi.org/10.1784/insi.2008.50.6.307 SN - 0007-1137 VL - 50 IS - 6 SP - 307 EP - 311 PB - British Institute of Non-Destructive Testing CY - Northampton AN - OPUS4-18034 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ewert, Uwe A1 - Zscherpel, Uwe A1 - Bavendiek, Klaus T1 - Digitale Radiologie in der ZfP - Belichtungszeit und Kontrastempfindlichkeit - Der Äquivalenzwert zur optischen Dichte des Films KW - Digitale Radiologie PY - 2005 SN - 1616-069X SN - 0948-5112 VL - 97 SP - 41 EP - 47 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung CY - Berlin AN - OPUS4-22947 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ewert, Uwe A1 - Zscherpel, Uwe A1 - Horky, M. A1 - Kennedy, J. A1 - Hutchinson, M. T1 - Ein neues PC-basiertes Konzept zur Beurteilung moderner digitaler Röntgendetektoren mit Referenzbildern T2 - DGZfP-JAHRESTAGUNG 2002 CY - Weimar, Germany DA - 2002-05-06 PY - 2002 AN - OPUS4-19973 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Thoms, M. A1 - Zscherpel, Uwe A1 - Ewert, Uwe T1 - Image Quality of High Definition Computed Radiography (HDCR) in NDT T2 - INDE 2007 CY - Chennai, India DA - 2007-04-24 PY - 2007 AN - OPUS4-19967 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ewert, Uwe A1 - Zscherpel, Uwe A1 - Beckmann, Jörg A1 - Bavendiek, K. T1 - Digital radiography - Films and digital detectors in comparison T2 - MINDTCE `09 - Malaysia international NDT conference and exhibiton `09 - NDT Driving industry safety, growth and performance CY - Kuala Lumpur, Malaysia DA - 2009-07-20 KW - Radiography KW - Film replacement KW - Computed radiography KW - Imaging plates KW - Digital detector arrays KW - Contrast sensitivity KW - SNR KW - standards PY - 2009 SP - 181 EP - 189 AN - OPUS4-20253 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Osterloh, Kurt A1 - Jechow, Mirko A1 - Fratzscher, Daniel A1 - Wrobel, Norma A1 - Zscherpel, Uwe A1 - Ewert, Uwe A1 - Bücherl, T. A1 - Hasenstab, A. A1 - Weiss, P. A1 - Weiss, C. A1 - Tannert, T. T1 - Strukturmerkmale im Holz - radiologisch gesehen N2 - Die radiologische Untersuchung von Holz ist hinsichtlich der Durchführung und Auswertung komplex. Im Gegensatz zu künstlich hergestellten Materialien zeichnet sich Holz besonders durch seine Heterogenität und Individualität aus, kein Stück ist wie das andere. Dies erschwert bei der radiologischen Inspektion die Fehlerdetektion, da diese teilweise schwer von natürlichen Wachstumsmerkmalen zu unterscheiden sind. Insektenfraßgänge und Hohlräume durch biologischen Abbau sind deutlich erkennbar, schwieriger wird es bei feinen Rissen und Anzeichen für Fäulnis. Metallische Einbauten wie Nägel und Bolzen sind natürlich gut zu erkennen, großflächigere Platten können jedoch den Einblick in die benachbarten Gebiete versperren. Klebstoffschichten sind im Röntgenbild nur dann sichtbar, wenn sie exakt parallel zum Strahlengang getroffen werden. Verschiedene Strukturmerkmale treten also radiologisch recht unterschiedlich in Erscheinung, deshalb liegt es nahe, zu deren Erkennung mehr als nur eine Durchstrahlungstechnologie anzuwenden. Während bei immobilen Objekten, d.h. Bauwerken und Bäumen, mobile Durchstrahlungstechniken mit Röntgen- oder Gammastrahlen (Se-75) in Frage kommen, stehen im Labor auch (schnelle) Neutronen alternativ zur Verfügung. Die verschiedenen Techniken, einschließlich der Tomographie mit Neutronen, werden an zwei größeren Prüfteilen demonstriert, einer Brettschichtholzprobe und einem Knotenpunkt aus einer Holzbrücke mit eingebauter Stahlplatte. Neutronen lassen Materialunterschiede differenzierter hervortreten und durchdringen sperrige Metallteile besser, trotz verringerter Bildqualität. An Verbesserungen wird derzeit gearbeitet. T2 - DGZfP-Jahrestagung 2010 CY - Erfurt, Deutschland DA - 2010-05-10 KW - Mobile Radiographie KW - Holzbauteilprüfung PY - 2010 SN - 978-3-940283-26-9 IS - DGZfP-BB 122 (Poster 14) SP - 1 EP - 2 CY - Berlin AN - OPUS4-22532 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beckmann, Jörg A1 - Zscherpel, Uwe A1 - Ewert, Uwe A1 - Skerik, M. T1 - Image Quality Assessment of CR Systems N2 - Computed Radiography exposure experiments on welded plate sections were performed to demonstrate that the requirements for pressure vessels weld inspection according to EN1435 or EN14784-2 class B can be achieved. The representative comparative studies of the image qualities were performed with standardized image quality indicators and image evaluation procedures on both film and digital radiographs. Recommendations for weld inspections with CR systems are drawn from the results. It is demonstrated that present CR systems can be used for weld inspection and produce images with testing class B if the selected X-ray tube voltage is reduced compared with the max. voltage of EN 14784-2 and set equivalent to maximum X-ray voltage values for steel as defined in the radioscopic standard EN 13068-3. The work was part of the European 'Filmfree' Project promoted during the 6’th framework. T2 - 10th European conference on non-destructive testing CY - Moscow, Russia DA - 2010-06-07 KW - Film KW - Digital radiography KW - Computed radiography KW - Image quality PY - 2010 UR - http://www.ndt.net/article/ecndt2010/reports/1_04_07.pdf IS - Paper 4.02.18 SP - 1 EP - 10 AN - OPUS4-22536 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ewert, Uwe A1 - Bavendiek, K. A1 - Robbins, J. A1 - Zscherpel, Uwe A1 - Bueno, C. A1 - Gordon, T. A1 - Mishra, D. T1 - New compensation principles for enhanced image quality in industrial radiology with digital detector arrays KW - Radiography KW - Film replacement KW - Digital detector arrays KW - Contrast sensitivity KW - SNR KW - CNR KW - Spatial resolution KW - Bad pixels KW - Standards KW - Compensation principles PY - 2010 SN - 0025-5327 VL - 68 IS - 2 SP - 163 EP - 168 PB - Society for Nondestructive Testing CY - Columbus, Ohio AN - OPUS4-22538 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Osterloh, Kurt A1 - Jechow, Mirko A1 - Fratzscher, Daniel A1 - Wrobel, Norma A1 - Zscherpel, Uwe A1 - Ewert, Uwe A1 - Bücherl, T. A1 - Schillinger, B. A1 - Schwabe, A. A1 - Hasenstab, A. A1 - Weiss, P. A1 - Weiss, C. A1 - Tannert, T. T1 - Durchstrahlungsverfahren - Ein komplexer Einblick in Objekte, ohne sie zu zerlegen T2 - Jahrestagung Archäometrie und Denkmalpflege 2010 CY - Bochum, Deutschland DA - 2010-09-15 KW - Mobile Radiographie KW - Neutronentomographie KW - Archäologischer Nassholzfund PY - 2010 SN - 0947-6229 IS - Metalla Sonderheft SP - 52 EP - 54 CY - Bochum AN - OPUS4-22539 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Beckmann, Jörg A1 - Zscherpel, Uwe A1 - Ewert, Uwe T1 - Untersuchungen zur Optimierung der Bildqualität in der Computer-Radiografie für die Schweißnahtprüfung N2 - In der Filmradiografie kann durch den Einsatz von Metallfolien und Metallfolienkombinationen der Bildkontrast verbessert werden. Die Mechanismen zur Erzeugung der latenten Röntgenbilder und deren Sichtbarmachung für das menschliche Auge sind in Speicherfolien nicht mit denen in einem Röntgenfilm identisch. Demzufolge lassen sich die in den Normen zur Filmradiografie veröffentlichten Empfehlungen zum Einsatz von Metallfolien und zur Auswahl der Röhrenspannung nicht unmittelbar auf die Computer-Radiografie zur Schweißnahtprüfung übertragen. Die Qualität digitaler Röntgenbilder wird von der Bildunschärfe und dem Kontrast-zu-Rausch-Verhältnis (CNR) bestimmt. Während die Norm EN 14784-1 handhabbare Verfahren zur Bestimmung der inneren Unschärfe und des Signal-zu-Rausch-Verhältnisses (SNR) beschreibt, sind die in EN 14784-2 vorgegebenen Vorgehensweisen zur Kontrastverbesserung durch die Vorgaben zur geeigneten Röhrenspannung und Metallfoliendicke für die Schweißnahtprüfung nicht ausreichend dargelegt. Um die Parameter zur Verbesserung der Bildqualität von CR-Systemen für den Fall der radiografischen Durchstrahlungsprüfung von Schweißnähten zu optimieren, wurden systematische Untersuchungen zum Einfluss eines Kupfer-Vorfilters, von Bleifolien-Speicherfolien-Kombinationen und der Röhrenspannung auf den Bildkontrast von Stahlstufenaufnahmen durchgeführt. Auf der Grundlage dieser Ergebnisse wurden Empfehlungen zum Einsatz der Metallfilter und -folienkombinationen sowie zur Auswahl geeigneter Röhrengrenzspannungen für die Speicherfolientechnik zur Optimierung der Durchstrahlungsprüfung von Schweißnähten abgeleitet. KW - Speicherfolien KW - Digitale Radiographie KW - Schweißnahtprüfung KW - Durchstrahlungsprüfung PY - 2008 SN - 0025-5300 VL - 50 IS - 10 SP - 552 EP - 559 PB - Hanser CY - München AN - OPUS4-18345 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Ewert, Uwe A1 - Beckmann, Jörg A1 - Bellon, Carsten A1 - Jaenisch, Gerd-Rüdiger A1 - Zscherpel, Uwe A1 - Jechow, Mirko A1 - Großer, A. T1 - Fehlergrößenabhängige Kontrastreduktion und zusätzliche Unschärfe durch Streustrahlung reduzierendie Bildqualität radiologischer Abbildungen - Film und digitale Detektoren im Vergleich T2 - DACH-Jahrestagung 2008 - Zerstörungsfreie Materialprüfung, ZfP in Forschung, Entwicklung und Anwendung CY - St. Gallen, Schweiz DA - 2008-04-28 KW - Digitale Radiologie KW - Streuverhältnis KW - Strahlenkontrast KW - Unschärfe PY - 2008 SN - 978-3-940283-09-2 IS - DGZfP-BB 113 (Di.1.A.1) SP - 133 EP - 144 AN - OPUS4-18349 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beckmann, Jörg A1 - Rachny, S. A1 - Zscherpel, Uwe A1 - Ewert, Uwe T1 - Improved Procedure for Computed Radiography - A Comparative Study on Welded Tube Sections by Film Radiography and Computed Radiography N2 - Different girth welds of tube sections have been inspected by elliptical projection technique according to the EN 1435. The radiographic images were taken by using both film radiography and computed radiography. The purpose of this study was to compare a C3 (AGFA D4) film system and a Duerr HDCR 35 NDT / HR IP imaging plate system with respect to the exposure time, image quality and the detection of fine weld imperfections. The results indicate to a dominant influence of the lead screens on the image contrast sensitivity if doing the inspection according to the EN 14748 -2 for imaging plate exposures. New screen combinations had been applied to make a computed radiograph of a testing class B quality possible. T2 - 17th World Conference on Non-Destructive Testing CY - Shanghai, China DA - 2008-10-25 KW - Film KW - Digital radiography KW - Computed radiography KW - Image quality PY - 2008 IS - Paper 69 SP - 1 EP - 7 PB - International Committee for Non-Destructive Testing CY - Shanghai AN - OPUS4-18412 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Beckmann, Jörg A1 - Großer, Anja A1 - Zscherpel, Uwe A1 - Ewert, Uwe T1 - Einfluss von Metall - Speicherfolien - Kombinationen auf die Bildqualität in der Computer - Radiographie N2 - Bei der Normgestaltung für Speicherfolien sind die Auswirkungen von Metallfolien und Metallfolienkombinationen auf die Bildqualität von Speicher-folienaufnahmen nicht ausreichend berücksichtigt worden. Es ist bekannt, dass bei Film - Metallfolien - Kombinationen zusätzlich zur Änderung der optischen Dichte und der Filmgranularität auch Änderungen der inneren Unschärfe durch den seitli-chen Energietransport in der Film – Metallfolien - Kombination entstehen, welche überwiegend durch ausgelöste Elektronen und zum Teil durch sekundäre Strahlung hervorgerufen werden. Gleichzeitig dienen die Metallfolien bei Röntgenaufnahmen mit Film als Streustrahlfilter und können zur Verbesserung des Bildkontrastes bei-tragen. Die Mechanismen zur Erzeugung des virtuellen Röntgenbildes und dessen Visualisierung sind in Speicherfolien nicht mit denen in einem Röntgenfilm iden-tisch. Demzufolge können die in den Normen festgelegten Vorschriften zum Einsatz von Metallfolien in der Filmradiographie nicht auf Speicherfolien uneingeschränkt übertragen werden. Anhand der hier erzielten Ergebnisse lassen sich Empfehlungen zum zukünftigen Einsatz der Metallfilter und -folienkombinationen für die Speicher-folientechnik zur Verbesserung der Bildgüte ableiten. T2 - DACH-Jahrestagung 2008 - Zerstörungsfreie Materialprüfung, ZfP in Forschung, Entwicklung und Anwendung CY - St. Gallen, Schweiz DA - 2008-04-28 PY - 2008 SN - 978-3-940283-09-2 IS - DGZfP-BB 113 (Poster 29) SP - 1 EP - 8 AN - OPUS4-18413 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Beckmann, Jörg A1 - Großer, Anja A1 - Zscherpel, Uwe A1 - Ewert, Uwe T1 - Einfluss von Metall-Speicherfolien-Kombinationen auf die Bildqualität in der Computer-Radiographie T2 - DACH-Jahrestagung 2008 - Zerstörungsfreie Materialprüfung, ZfP in Forschung, Entwicklung und Anwendung CY - St. Gallen, Schweiz DA - 2008-04-28 KW - Speicherfolien KW - Durchstrahlungsprüfung KW - Computer Radiographie KW - Metallfolien PY - 2008 SN - 978-3-940283-09-2 IS - DGZfP-BB 113 (Poster 29) SP - 847 EP - 856 AN - OPUS4-18351 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Osterloh, Kurt A1 - Ewert, Uwe A1 - Rädel, Christoph A1 - Zscherpel, Uwe A1 - Hasenstab, A. A1 - Bücherl, T. T1 - Radiographie und Tomographie von Holz mit Neutronen T2 - DGZfP-Jahrestagung 2008 CY - St. Gallen, Switzerland DA - 2008-04-28 KW - Materialgeschichtliches KW - Möglichkeiten der Neutronenradiographie PY - 2008 SN - 978-3-940283-09-2 IS - DGZfP-BB 113 (Poster 30) SP - 727 EP - 733 AN - OPUS4-20714 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Osterloh, Kurt A1 - Zscherpel, Uwe A1 - Ewert, Uwe T1 - Threat detection and imaging T2 - 2nd Security research conference Karlsruhe CY - Karlsruhe, Germany DA - 2007-09-12 KW - Digitale Bildbearbeitung KW - Automatische Rauscherkennung und Kompensation PY - 2007 SN - 978-3-86644-147-7 SP - 179 EP - 182 PB - Universitätsverlag Karlsruhe AN - OPUS4-20715 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Osterloh, Kurt A1 - Zscherpel, Uwe A1 - Rädel, Christoph A1 - Weidemann, Gerd A1 - Meinel, Dietmar A1 - Goebbels, Jürgen A1 - Ewert, Uwe A1 - Hasenstab, A. A1 - Bücherl, T. T1 - Durchstrahlungsprüfung von Holz T2 - DGZfP-Jahrestagung 2007 CY - Fürth, Deutschland DA - 2007-05-14 KW - Digitale Radiographie KW - Tomographie KW - Spaltneutronen KW - Neutronenradiographie PY - 2007 SN - 978-3-931381-98-1 IS - DGZfP-BB 104 (Vortrag 40) SP - 1 EP - 12 AN - OPUS4-20717 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Osterloh, Kurt A1 - Wrobel, Norma A1 - Fratzscher, Daniel A1 - Jechow, Mirko A1 - Zscherpel, Uwe A1 - Ewert, Uwe A1 - Hasenstab, A. T1 - Backscatter radiation - using X-rays for illumination T2 - MATEST 2009 CY - Cavtat/Dubrovnik, Croatia DA - 2009-09-23 KW - X-ray back scatter KW - Unilateral access KW - Twisted slit collimator KW - Pinhole camera principle with high energy radiation PY - 2009 SN - 978-953-7283-03-2 IS - #12 SP - 1 EP - 11 AN - OPUS4-20709 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Osterloh, Kurt A1 - Wrobel, Norma A1 - Kunte, Hans-Jörg A1 - Zscherpel, Uwe A1 - Ewert, Uwe T1 - Making the world a safer place - some know-how already exists T2 - MATEST 2009 CY - Cavtat/Dubrovnik, Croatia DA - 2009-09-23 KW - Existing hazards KW - Threat detection KW - Interdisciplinary approach KW - Existing safety rules and procedures KW - Bridging safety and security KW - Common definitions PY - 2009 SN - 978-953-7283-03-2 IS - #10 SP - 1 EP - 7 AN - OPUS4-20710 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Osterloh, Kurt A1 - Zscherpel, Uwe A1 - Ewert, Uwe T1 - X-ray backscatter radioscopy for security applications with a novel twisted slit collimator KW - Röntgenrückstreuung KW - Kamera für hochenergetische Strahlung PY - 2009 SN - 1619-2486 IS - 10 SP - 22 EP - 25 PB - ddp Goldenbogen CY - Dresden AN - OPUS4-20711 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Osterloh, Kurt A1 - Zscherpel, Uwe A1 - Ewert, Uwe T1 - Visualisation of radioactive materials and backscatter radiography with a novel collimation based camera system T2 - 4th Security research conference Karlsruhe CY - Karlsruhe, Germany DA - 2009-09-29 KW - Kamera für hochenergetische Strahlung KW - Bildliche Wiedergabe der Formen von Strahlenquellen KW - Röntgenrückstreustrahlung KW - Anwendung für die öffentliche Sicherheit (Security) PY - 2009 IS - #052 SP - 1 EP - 8 AN - OPUS4-20712 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Redmer, Bernhard A1 - Ewert, Uwe A1 - Rädel, Christoph A1 - Zscherpel, Uwe A1 - Likhatchov, A.V. A1 - Pickalov, V.V. A1 - Neundorf, B. T1 - Mobile 3D-X-Ray Tomography for Analysis of Planar Defects in Welds by "Tomocar" N2 - Tomographical Computer Aided Radiology (TomoCAR) is based on the mechanical position control of an X-ray tube in front of a welding seam and the application of a planar array detector behind it. Several hundred radiometric projections in small angle steps are acquired. The tomographical reconstruction allows the three-dimensional (3D) representation of the defects. A new radiometric array detector system with a small internal unsharpness and high image contrast is used for the 2- and 3-dimensional visualization and sizing of planar defects with a defect opening of less than 100 µm. This detector is based on a CMOS-flat panel with a direct converting CdTe-single crystal layer. The small design allows the application of the mobile testing equipment for mechanized X-ray inspection in industrial plants. The physical pixel size of the detector amounts to 0,1x0,1 mm². Nevertheless, this system yields a better spatial resolution than indirect converting detectors (e.g. cameras with fluorescence layers of Gd2O2S). It allows the reliable detection of planar defects with openings far below the detector pixel size by subpixel resolution. 'TomoCAR' is qualified at present in the context with a German pilot study following to the ENIQ guidelines for the employment within the nuclear power industry. T2 - 16th World Conference on Nondestructive Testing CY - Montreal, Canada DA - 2004-08-30 KW - Digitale Radiologie KW - Radiometrie KW - Laminografie KW - Mobile Anwendungen PY - 2004 SP - 8 pages PB - International Committee for Non-Destructive Testing CY - Montreal AN - OPUS4-4717 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ewert, Uwe A1 - Zscherpel, Uwe T1 - New detectors and perspectives in industrial radiography KW - Radiographie KW - Detectors KW - ZfP KW - Corrosion PY - 2005 VL - 12 IS - 1 SP - 59 EP - 71 PB - National Association for Applications of Radioisotopes and Radiation in Industry CY - Mumbai AN - OPUS4-7229 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ewert, Uwe A1 - Zscherpel, Uwe T1 - Najnowsze trendy w cyfrowej radiografii przemystowej / Neue Trends in der digitalen Radiographie in der Industrie KW - Radiographie KW - Detektoren KW - ZfP KW - Korrosion PY - 2005 SN - 0209-1763 SN - 0137-3684 IS - 1 SP - 9 EP - 16 CY - Warszawa AN - OPUS4-7230 LA - pol AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Redmer, Bernhard A1 - Ewert, Uwe A1 - Rädel, Christoph A1 - Zscherpel, Uwe A1 - Likhatchov, A.V. A1 - Pickalov, V.V. T1 - Mobiler Einsatz digitaler Röntgen-Detektoren zur tomografischen Visualisierung flächiger Fehler im Anlagenbereich T2 - Jahrestagung Zerstörungsfreie Materialprüfung 2004 CY - Salzburg, Österreich DA - 2004-05-17 KW - Digitale Radiologie KW - Zeilenkamera KW - Flächendetektor KW - Laminografie KW - Mobile Anwendungen PY - 2004 UR - http://www.ndt.net/article/dgzfp04/papers/v62/v62.htm SN - 3-931381-55-2 SP - 1(?) EP - 9(?) PB - DGZfP CY - Berlin AN - OPUS4-5227 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ewert, Uwe A1 - Zscherpel, Uwe A1 - Bavendiek, K. T1 - Digitale Radiologie in der ZfP KW - Industrielle digitale Radiologie KW - ZfP KW - Filmersatz KW - Flachdetektor KW - Bildqualität KW - Signal/Rausch-Verhältnis KW - Kontrastempfindlichkeit PY - 2005 SN - 1616-069X SN - 0948-5112 VL - 97 SP - 41 EP - 47 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung CY - Berlin AN - OPUS4-11861 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Ewert, Uwe A1 - Zscherpel, Uwe A1 - Bavendiek, K. T1 - Digitale Radiologie in der ZfP T2 - DGZfP Jahrestagung CY - Rostock, Deutschland DA - 2005-05-02 KW - Industrielle digitale Radiologie KW - ZfP KW - Filmersatz KW - Flachdetektor KW - Bildqualität KW - Signal/Rausch-Verhältnis KW - Kontrastempfindlichkeit PY - 2005 SN - 3-931381-64-1 N1 - Serientitel: Berichtsband / Deutsche Gesellschaft für zerstörungsfreie Prüfung e. V. – Series title: Berichtsband / Deutsche Gesellschaft für zerstörungsfreie Prüfung e. V. IS - 94-CD SP - 1(?) EP - 10(?) PB - DGZfP CY - Berlin AN - OPUS4-11862 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Osterloh, Kurt A1 - Hasenstab, Andreas A1 - Zscherpel, Uwe A1 - Goebbels, Jürgen A1 - Ewert, Uwe T1 - Non-Destructive Testing of Wood by Radiography N2 - Throughout human history, wood has been used for various purposes: for building shelters, houses and bridges, for manufacturing furniture and household or agricultural appliances (from ploughs to spoons), as burning material or simply as walking sticks. Contemporarily, vast amounts of wood are going into paper production. As a consequence, different qualities of wood are selected appropriately for the various applications. Beams incorporated into buildings and constructions have to be sturdy and durable; boards for furniture are supposed to be free of knots or are expected to have certain ornamental structures. As long as wood is not simply destined for burning it should be free of undesired knots or internal damages such as rot or worm holes. Particularly in cases of infestation with wood destroying fungi that definitely impairs mechanical strength and even may generate hollows such damages are frequently invisible from the outside. Radiographic methods are capable to detect internal damages as well as hidden knots without the need of drilling holes or cutting a specimen to pieces. The most thoroughly method to visualise the interior of a wooden specimen is tomography which shows annual growth rings in their complete circumference and all the knots or damages that might be included. However, some of them as well as patterns of annual rings suitable for dendrological investigations are recognisable with a less laborious method that might be applicable even in the field, i.e. contemporary digital radiography combined with image processing. Samples of lumber shall be presented showing the typical annual ring structures and some infested areas. T2 - MATEST 2005 CY - Opatija, Croatia DA - 2005-10-06 KW - NDT of wood KW - Quality of wood KW - Tomography KW - Presentation of spatial data KW - Digital radiography KW - Image processing KW - Noise KW - On-site radiography PY - 2005 SN - 953-7283-00-3 SP - 108 EP - 119 PB - Croatian Society of Non-Destructive Testing (CrSNDT) CY - Opatija AN - OPUS4-11865 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zscherpel, Uwe A1 - Ewert, Uwe A1 - Infanzon, S. A1 - Rastkhan, N. A1 - Vaidya, P. R. A1 - Einav, I. A1 - Ekinci, S. T1 - Radiographic Evaluation of Corrosion and Deposits in Pipelines - Results of an IAEA Co-ordinated Research Programme T2 - 9th European Conference on NDT CY - Berlin, Germany DA - 2006-09-25 KW - ZfP KW - Radiographie KW - Korrosion KW - Deposit KW - Rohrleitungen KW - IAEA CRP KW - Tangentielle Projektionstechnik KW - Doppelwandtechnik KW - Anwendungsgrenze PY - 2006 SN - 3-931381-86-2 SP - 1(?) EP - 14(?) PB - European Federation for Non-Destructive Testing CY - Berlin AN - OPUS4-13873 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beckmann, Jörg A1 - Döring, Joachim A1 - Bartusch, Jürgen A1 - Zscherpel, Uwe A1 - Ewert, Uwe A1 - Erhard, Anton T1 - Time Domain Spectroscopy Techniques for Non Destructive Contact less Flaw Detection and Imaging in Advanced Materials T2 - 9th European Conference on NDT CY - Berlin, Germany DA - 2006-09-25 KW - Time domain spectroscopy KW - Air coupled ultrasound KW - Pulsed THz radiation system KW - Pulse compression KW - THz imaging PY - 2006 SN - 3-931381-86-2 SP - 1(?) EP - 8(?) PB - European Federation for Non-Destructive Testing CY - Berlin AN - OPUS4-13874 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beckmann, Jörg A1 - Richter, Heike A1 - Zscherpel, Uwe A1 - Ewert, Uwe A1 - Weinzierl, J. A1 - Schmidt, L.-P. A1 - Rutz, F. A1 - Koch, M. A1 - Richter, H. A1 - Hübers, H.-W. T1 - Imaging Capability of Terahertz and Millimeter-Wave Instrumentations for NDT of Polymer Materials T2 - 9th European Conference on NDT CY - Berlin, Germany DA - 2006-09-25 KW - Time domain spectroscopy KW - Air coupled ultrasound KW - Pulsed THz radiation system KW - Pulse compression KW - THz imaging PY - 2006 SN - 3-931381-86-2 SP - 1(?) EP - 9(?) PB - European Federation for Non-Destructive Testing CY - Berlin AN - OPUS4-13875 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Osterloh, Kurt A1 - Hasenstab, Andreas A1 - Zscherpel, Uwe A1 - Alekseychuk, Oleksandr A1 - Meinel, Dietmar A1 - Goebbels, Jürgen A1 - Ewert, Uwe T1 - Radiographic and Tomographic Testing of Wood T2 - 9th European Conference on NDT CY - Berlin, Germany DA - 2006-09-25 KW - NDT of wood KW - Naturally grown material with individual structuring KW - Loss of integrity due to biological decay (rot) KW - CT KW - DR KW - IP PY - 2006 SN - 3-931381-86-2 SP - 1(?) EP - 10(?) PB - European Federation for Non-Destructive Testing CY - Berlin AN - OPUS4-14170 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Ewert, Uwe A1 - Jaenisch, Gerd-Rüdiger A1 - Osterloh, Kurt A1 - Zscherpel, Uwe ED - Czichos, Horst ED - Tetsuya Saito, ED - Leslie Smith, T1 - Industrial Radiology KW - Fundamentals KW - Particle-Based Radiological Methods KW - Film Radiography KW - Digital Radiological Methods KW - Public Safety and Security PY - 2006 SN - 978-3-540-20785-6 SP - 844 EP - 858 PB - Springer CY - Berlin AN - OPUS4-14473 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bavendiek, K. A1 - Heike, U. A1 - Meade, W. D. A1 - Zscherpel, Uwe A1 - Ewert, Uwe T1 - New Digital Radiography Procedure Exceeds Film Sensitivity Considerably in Aerospace Applications T2 - 9th European Conference on NDT CY - Berlin DA - 2006-09-25 KW - Radiographie KW - Filmersatz KW - Luftfahrt KW - Bildqualität KW - Signal/Rausch-Verhältnis PY - 2006 SN - 3-931381-86-2 SP - 1(?) EP - 16(?) PB - European Federation for Non-Destructive Testing CY - Berlin AN - OPUS4-15713 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zscherpel, Uwe A1 - Ewert, Uwe A1 - Bavendiek, K. T1 - Possibilities and Limits of Digital Industrial Radiology: The new high contrast sensitivity technique - Examples and system theoretical analysis T2 - DIR 2007 - International Symposium on Digital industrial Radiology and Computed Tomography CY - Lyon, France DA - 2007-06-25 KW - Digital radiography KW - High contrast sensitivity technique KW - Digital detector arrays KW - NDT film systems KW - Computed Radiography (CR) with imaging plates KW - Film replacement KW - Image quality KW - Basic spatial resolution KW - Signal/noise ratio KW - Contrast sensitivity PY - 2007 IS - (Vortrag V1) SP - 1 EP - 17 CY - Lyon, France AN - OPUS4-16073 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Ewert, Uwe A1 - Zscherpel, Uwe A1 - Fratzscher, Daniel A1 - Alekseychuk, Oleksandr A1 - Einav, I. A1 - Infanzon, S. A1 - Zirnhelt, J. T1 - Optimization of Digital Industrial Radiography (DIR) Techniques for Specific Applications: An IAEA Coordinated Research Project T2 - 4. Conferencia Panamericana de END CY - Buenos Aires, Argentina DA - 2007-10-22 KW - Radiographie KW - Digitale Detektoren KW - Grenzen der Bildqualität KW - Preiswerte Prüftechnik PY - 2007 SN - 978-987-23957-0-4 IS - CD-ROM SP - 1 EP - 6 AN - OPUS4-16424 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Ewert, Uwe A1 - Zscherpel, Uwe A1 - Bavendiek, K. T1 - Strategies for Film Replacement in Radiography - a comparative study T2 - 4. Conferencia Panamericana de END CY - Buenos Aires, Argentina DA - 2007-10-22 KW - Radiographie KW - Digitale Detektoren KW - Grenzen der Bildqualität KW - Vergleich Film KW - Speicherfolien KW - Detektor-Arrays PY - 2007 SN - 978-987-23957-0-4 IS - CD-ROM SP - 1 EP - 18 AN - OPUS4-16425 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Osterloh, Kurt A1 - Bücherl, T. A1 - Lierse von Gostomski, C. A1 - Zscherpel, Uwe A1 - Ewert, Uwe A1 - Bock, S. T1 - Filtering algorithm for dotted interferences N2 - An algorithm has been developed to remove reliably dotted interferences impairing the perceptibility of objects within a radiographic image. This particularly is a major challenge encountered with neutron radiographs collected at the NECTAR facility, Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II): the resulting images are dominated by features resembling a snow flurry. These artefacts are caused by scattered neutrons, gamma radiation, cosmic radiation, etc. all hitting the detector CCD directly in spite of a sophisticated shielding. This makes such images rather useless for further direct evaluations. One approach to resolve this problem of these random effects would be to collect a vast number of single images, to combine them appropriately and to process them with common image filtering procedures. However, it has been shown that, e.g. median filtering, depending on the kernel size in the plane and/or the number of single shots to be combined, is either insufficient or tends to blur sharp lined structures. This inevitably makes a visually controlled processing image by image unavoidable. Particularly in tomographic studies, it would be by far too tedious to treat each single projection by this way. Alternatively, it would be not only more comfortable but also in many cases the only reasonable approach to filter a stack of images in a batch procedure to get rid of the disturbing interferences. The algorithm presented here meets all these requirements. It reliably frees the images from the snowy pattern described above without the loss of fine structures and without a general blurring of the image. It consists of an iterative, within a batch procedure parameter free filtering algorithm aiming to eliminate the often complex interfering artefacts while leaving the original information untouched as far as possible. KW - Neutron KW - Radiography KW - Tomography KW - Filtering KW - Evaluation KW - NECTAR PY - 2011 DO - https://doi.org/10.1016/j.nima.2011.01.107 SN - 0168-9002 SN - 0167-5087 VL - 651 IS - 1 SP - 171 EP - 174 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-24917 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Osterloh, Kurt A1 - Fratzscher, Daniel A1 - Schwabe, A. A1 - Schillinger, B. A1 - Zscherpel, Uwe A1 - Ewert, Uwe T1 - Radiography and partial tomography of wood with thermal neutrons N2 - The effective high neutron scattering absorption coefficient of hydrogen (48.5 cm²/g) due to the scattering allows neutrons to reveal hydrocarbon structures with more contrast than X-rays, but at the same time limits the sample size and thickness that can be investigated. Many planar shaped objects, particularly wood samples, are sufficiently thin to allow thermal neutrons to transmit through the sample in a direction perpendicular to the planar face but not in a parallel direction, due to increased thickness. Often, this is an obstacle that prevents some tomographic reconstruction algorithms from obtaining desired results because of inadequate information or presence of distracting artifacts due to missing projections. This can be true for samples such as the distribution of glue in glulam (boards of wooden layers glued together), or the course of partially visible annual rings in trees where the features of interest are parallel to the planar surface of the sample. However, it should be possible to study these features by rotating the specimen within a limited angular range. In principle, this approach has been shown previously in a study with fast neutrons [2]. A study of this kind was performed at the Antares facility of FRM II in Garching with a 2.6×107/cm² s thermal neutron beam. The limit of penetration was determined for a wooden step wedge carved from a 2 cm×4 cm block of wood in comparison to other materials such as heavy metals and Lucite as specimens rich in hydrogen. The depth of the steps was 1 cm, the height 0.5 cm. The annual ring structures were clearly detectable up to 2 cm thickness. Wooden specimens, i.e. shivers, from a sunken old ship have been subjected to tomography. Not visible from the outside, clear radial structures have been found that are typical for certain kinds of wood. This insight was impaired in a case where the specimen had been soaked with ethylene glycol. In another large sample study, a planar board made of glulam has been studied to show the glued layers. This study shows not only the limits of penetration in wood but also demonstrates access to structures perpendicular to the surface in larger planar objects by tomography with fast neutrons, even with incomplete sets of projection data that covers an angular range of only 90° or even 60°. KW - Neutron computed tomography KW - Limited angle tomography KW - Wood KW - Annual rings PY - 2011 DO - https://doi.org/10.1016/j.nima.2011.02.095 SN - 0168-9002 SN - 0167-5087 VL - 651 IS - 1 SP - 236 EP - 239 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-24918 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wrobel, Norma A1 - Osterloh, Kurt A1 - Zscherpel, Uwe A1 - Ewert, Uwe ED - Ender, J. ED - Fiege, J. T1 - Variable irradiation geometry with a nex X-ray backscatter camera for security applications T2 - Future Security 2011 Conference CY - Berlin, Germany DA - 2011-09-05 KW - Technical safety and public security KW - Bridging separate competence areas PY - 2011 SN - 978-3-8396-0295-9 SP - 128 EP - 131 CY - Berlin AN - OPUS4-25355 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -