Filtern
Dokumenttyp
- Beitrag zu einem Sammelband (11) (entfernen)
Referierte Publikation
- nein (11)
Schlagworte
- Unilateral access (2)
- Automatische Rauscherkennung und Kompensation (1)
- Backscatter (1)
- Bridging safety and security (1)
- Common definitions (1)
- Computertomography (1)
- Diaphragm for high energy radiation (1)
- Digital Radiological Methods (1)
- Digital radiography (1)
- Digitale Bildbearbeitung (1)
- Digitale Radiographie (1)
- Dual Energy (1)
- Existing hazards (1)
- Existing safety rules and procedures (1)
- Explosives (1)
- Fibre composites (1)
- Film Radiography (1)
- Flash generator (1)
- Flaw Detection (1)
- Fundamentals (1)
- Image processing (1)
- Interdisciplinary approach (1)
- Laminography (1)
- Metal Detector Test Trials (1)
- Mine Detection (1)
- Mobiles Röntgen (1)
- Multiple View Inspection (1)
- NDT of wood (1)
- Noise (1)
- On-site radiography (1)
- Particle-Based Radiological Methods (1)
- Pinhole camera principle with high energy radiation (1)
- Presentation of spatial data (1)
- Prohability of Detection (1)
- Public Safety and Security (1)
- Quality of wood (1)
- Receiver Operating Characteristics (1)
- Security application (1)
- Terahertz Imaging (1)
- Threat Detection (1)
- Threat detection (1)
- Tomography (1)
- Twisted slit collimator (1)
- X-ray back scatter (1)
- X-ray backscatter technology (1)
- X-ray light materials (1)
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.
In diesem Beitrag wird die Anwendung von Radiographiesystemen zum Auffinden von Holzschäden beschrieben. Die Anlage besteht aus einer mobilen Röntgenblitzröhre und einem digitalen Radiographiesystem mit Speicherfolie oder einem Flachdetektor. An Hand der durchgeführten Versuche an Laub- und Nadelbäumen sowie an Eichenbalken der Marienkirche der Lutherstadt- Wittenberg wird die Detektion innerer Schäden gezeigt.
The detection of defects in aircraft components or parts of a power plant or mines in the ground is connected with the task to distinguish between signals caused be the item searched for and noisy signals from other sources. The reliability of the system is the better the better the system is in detecting the wanted signal and avoiding false alarms caused by noise. It is usual to measure the reliability of diagnostic systems in terms of ROC-curves (Re-ceiver Operating Characteristics) and POD-curves (Probability of Detec-tion). The ROC curves describe the POD versus Probability of False Alarm with growing system sensitivity along the curve. POD curves describe the Probability of Detection for a fixed sensitivity for a variation of item sizes or depths. Reliability of the whole system is always a composition of the physics
and technique, application influences and the human factors. For the scien-tific understanding and possibilities of improvement, decomposition accord-ing to a modular model is helpful. The authors present their experiences with the reliability evaluation of metal detectors for humanitarian demining and an NDT system of mechanized ultrasonic phased array testing of copper welds. The special concern in demining is the influence of soil types, detec-tors and the experiences of human beings.
Industrial Radiology
(2006)
Threat detection and imaging
(2007)