X Ray CT/7 Abstract A small forest-ball was manufactured and calibrated using CMM F25. An industrial CT called Metrotom1500 was calibrated by the small forest-ball and another big forest-ball produced by Carl Zeiss. These two forest-balls were separately measured at two different magnifications of the industrial CT, and the measurement results could meet the maximum…
X Ray CT/6 Abstract This paper presents the principles of industrial x-ray-computed tomography (XCT) and its enormous potentials for the non-destructive 3D measurement and quality assurance of technical parts. Due to many overall factors and many nonlinear factors having an influence on the tomographic imaging process, the reconstructed volume model and thus the measurement results,…
X Ray CT/5 Abstract Non-destructive testing (e.g. defect detection, material characterization), reverse engineering, fibre orientation, and morerecently coordinate metrology represent the broad range of today`s applications of industrial X-ray computed tomography(CT). However, the use of CT as a coordinate measurement system opens up new challenges to technology. This is especiallytrue of dimensional inspections of multi-material…
X Ray CT/4 Abstract X-ray computed tomography (CT) is increasingly used in industry for dimensional quality controlpurposes. However, due to numerous and complex error sources and to the current lack ofstandardization, industrial users are facing difficulties in the evaluation of CT measurements uncertaintyand metrological performance of CT systems. This paper analyses the state of the…
X Ray CT/3 Abstract X-ray computed tomography (XCT) is increasingly being used for evaluating quality and conformance of complex products, including assemblies and additively manufactured parts. The metrological performance and traceability of XCT nevertheless remains an important research area that is reviewed in this paper. The error sources influencing XCT measurement results are discussed, along…
X Ray CT/2 Abstract The number of industrial applications of Computed Tomography (CT) is large and rapidly increasing. After a brief market overview, the paper gives a survey of state of the art and upcoming CT technologies, covering types of CT systems, scanning capabilities, and technological advances. The paper contains a survey of application examples from the…
X Ray CT/1 Abstract The paper gives a survey of the upcoming use of X-ray computed tomography (CT) for dimensional quality control purposes: i.e. for traceable measurement of dimensions of technical (mechanical) components and for tolerance verification of such components. It describes the basic principles of CT metrology, putting emphasis on issues as accuracy, traceability…
Existing techniques for measuring and characterising anisotropy are discussed. The advantages are suggested in treating anisotropic surfaces as self-affine fractals, characterised by two parameters, the fractal dimension and the topothesy. These parameters are conveniently determined experimentally by measuring the slope and intercept of a logarithmic plot of the structure function. A 3D version of the…
Abstract Proliferation of redundant parameters for characterizing surface roughness is explained as a historical consequence of the predominant influence of instrument manufacturers over users. Problems of roughness characterization are introduced: high and low-pass filtering, transitional topographies, sampling error. The needs of three classes of user, the machinist, the researcher and the quality control engineer, are…
Abstract A number of specimen surfaces, including machined surfaces and calibration standards, are examined by a stylus instrument on-line to a microcomputer. For each measuement on each specimen 14 roughness parameters are computed for each of 10 profiles, and the mean and standard deviation of each parameter is calculated. Variations of up to 15% are…
Profile measurements of the surface topography of engineering components are often used in attempts to assess the functional suitability of surfaces. This paper reviews the definitions and properties of a large number of parameters which are used to characterize measurements of this type.
