Robert Schmitt, Susanne Nisch
Today the scanning-technology on coordinate measuring machines (CMMs) is used for tactile detection of form deviations. Many companies apply CMMs instead of form measuring devices because of their high flexibility and the possibility of fast workpiece inspection. However, the kinematic of CMMs is more complex than the one of specialized form measurement devices. Dynamic effects, like centrifugal force of roundness measuring, result in a rising measurement uncertainty. The right setup of scanning parameters, like point density and scanning speed, is a challenging task. It is up to the machine...
XIX IMEKO World Congress
· TC14
· 2009
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M. G. Cox, Alistair B. Forbes, P. M. Harris, I. M. Smith
Calibration procedures are widely implemented in metrology. This paper considers the evaluation of measurement uncertainty associated with the use of a calibration function. Three methods for uncertainty evaluation are described and the differences in the results returned are discussed. A simple calibration function is used to illustrate these differences.
XIX IMEKO World Congress
· TC21
· 2009
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Albert Garcia Benadí, S. Shariat-Panahi, Joaquín del Río, Antoni Mànuel
In this article an improvement of a calibration process of measurement equipment in the field of dimensional metrology is presented. Devices under calibration process are dial comparators. The semi-automated process is focused on the acquisition and treatment of the calibration data. The aim of the semi-automated implementation is the improvement of the process performance for error minimization produced by human factors and a reduction of time. We have implemented semi-automated process is as the operator experience and knowledge also brings quality to the calibration process itself.
XIX IMEKO World Congress
· TC8
· 2009
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Zbigniew Moron, Tomasz Grysinski
The four-point probe method, elaborated by van der Pauw, can be applied also in absolute measurements of electrical conductivity of electrolyte solutions. Conductance cells designed and used according to the method have their cell constant dependent on a single geometrical dimension only – the height. One of such designs, with electrodes located in chambers separated from the measuring space of the cell by narrow gaps, has especially advantageous properties as a calculable cell. This was presented in the previous works of the main author of this paper. The analysis performed there indicates...
XIX IMEKO World Congress
· TC13
· 2009
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Darko Vasic, Silvano Perkovic, Vedran Bilas
Low-frequency electromagnetic measurement of inner radius of metal tubes is indispensable in their production and condition assessment. Two challenges in such a measurement are corrections for variations in electromagnetic properties of a tube and coil radial offset. The authors investigate adaptation of the single-coil method for measurement of inner radius to a small scale embedded system based on a DSP microcontroller. The electromagnetic gauge can be used for both magnetic and nonmagnetic tubes and its performances are comparable to the laboratory implementation of the method based on a...
XIX IMEKO World Congress
· TC4
· 2009
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S. Shariat-Panahi, F. Corrêa Alegria, Antoni Mànuel, Joaquín del Río
During the past decades, Ocean Bottom Seismometers (OBS) have played a key role in permanent seismic activity monitoring at sea as well as allowing a better understating of the earth interior. Data collected by the instrument can provide information on the ocean bottom sub-layers down to a depth of 40 km beneath the ocean floor. The accuracy of the results directly depends on the time drift of the equipment due to change of environmental conditions. Time base of the OBS is given by a unique stable crystal oscillator. This paper presents the time drift study of an Ocean Bottom Seismometer in...
XIX IMEKO World Congress
· TC22
· 2009
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Joaquín del Río, Daniel Toma, Antoni Mànuel, Helena Geirinhas Ramos
Marine Sensor Networks (MSN) and ocean observatories are complex data acquisition systems where in many cases, synchronized acquisition is needed between the different networked nodes. In the development of OBSEA project, (EMSO CAC-2007-09) distributed acquisitions nodes based in low power embedded systems have to be synchronized. This paper presents the evaluation results obtained using IEEE 1588 standard as the synchronization protocol for the networked acquisition devices and a IM3220 microprocessor based embedded system.
XIX IMEKO World Congress
· TC4
· 2009
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Luís Rosado, Telmo Santos, Moisés Piedade, Pedro M. Ramos, Pedro Vilaça
In this paper a new non-destructive testing (NDT) system focusing on micro size superficial defects in metals is presented. The innovative system is composed by a new type of eddy currents probe, electronic devices for signal generation, conditioning and conversion, automated mechanized scanning and analysis software. The key original aspect of this system is the new type of eddy currents probe. This new IOnic probe provides enhanced lift-off immunity and improved sensitivity for micro size imperfections. The probe concept was studied using a Finite Element Modeling (FEM) tool and...
XIX IMEKO World Congress
· TC4
· 2009
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Mariolino De Cecco, Marco Pertile, Luca Baglivo, Giorgio Parzianello, Massimo Lunardelli, Francesco Setti, Antonio Selmo
A method for the reconstruction of a 3D shape is described and applied to a practical measurement case. Multiple stereo systems are employed to measure a 3D surface with superimposed colored markers. The described procedure comprises a detailed uncertainty analysis of all the measurement phases, and a statistical compatibility analysis of the colored markers measured by different stereo pairs. The compatible acquired markers are statistically merged in order to obtain a measurement of a 3D shape and an evaluation of the associated uncertainty. The obtained results show that the selected...
XIX IMEKO World Congress
· TC14
· 2009
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David Samper, Jorge Santolaria, Jorge Juan Pastor, Juan José Aguilar
This paper describes the Metrovisionlab computer application implemented as a toolbox for the Matlab program. It is designed for learning the key aspects of camera calibration techniques in dimensional metrology applications such as laser triangulation sensors and photogrammetry or stereovision systems. The software is used in several industrial vision courses for senior undergraduate mechanical engineering students. The application: 1) simulates a virtual camera, providing a simple and visual understanding of how the various characteristics of a camera influence the image that it captures;...
XIX IMEKO World Congress
· TC1
· 2009
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