J. Santolaria, J.J. Aguilar, C. Cajal, M.A. Lope
A technique for intrinsic and extrinsic calibration of a laser stripe sensor (LSS) integrated in a coordinate measurement arm (CMA) is presented in this paper. By means of a single calibration object, a one-step calibration method to obtain both intrinsic (laser plane, CCD sensor and camera geometry) and extrinsic parameters related to CMA main frame has been developed, allowing the integration of LSS and CMA mathematical models. The results obtained in accuracy and repeatability experimental tests show the suitable performance of this method, as well as a great ease of use and a very low...
XVIII IMEKO World Congress
· TC21
· 2006
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Hung-kung Liu, William F. Guthrie, Juan Soto
In this paper we introduce an approach for constructing statistical metrology tools with a Microsoft Excel based interface that uses the open source statistical package R as the computational engine. These metrology tools will enable Excel users to access a larger array of specialized statistical tools for metrology. We will describe our general approach and demonstrate one tool - an automated uncertainty calculator. This uncertainty calculator provides users with a simple and flexible tool for estimating measurement uncertainty using the methods outlined in the ISO Guide to the Expression...
XVIII IMEKO World Congress
· TC21
· 2006
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Daniela Ichim, Franco Pavese
The paper will describe the techniques that have been used to perform the comparison on large batches of cryogenic semiconductor-type thermometers, calibrated for the CERN LHC and the main results obtained: they concern either the uncertainty of the CernoxTM thermometers under calibration and the behaviour of the standards used during the calibrations.
XVIII IMEKO World Congress
· TC21
· 2006
· Download
F. Adamo, F. Attivissimo, G. Cavone, N. Giaquinto, A. M. L. Lanzolla
The paper deals with the problem of pointing out and mark the various kind of defects (mainly scars, wrinkles and fire brandings) of tanned calf leathers used in many industrial areas (e.g. household couches and car seats lining ones). In the first experiments here presented the authors try to use the same inspection method previously successfully applied to quality control of hands-made satin glasses, that is a two-dimensional wavelet-based de-noising technique of high resolution images of the leather under inspection; according to multiresolution analysis, this method produces a suitable...
XVIII IMEKO World Congress
· TC21
· 2006
· Download
A. Silva Ribeiro, J. Alves e Sousa, C. Oliveira Costa, M. Pimenta de Castro
Linear Regression Analysis (LRA) is one of the statistical tools most intensively used in all branches of science, with many applications in the study of measurement processes and is therefore important in metrology. The implementation of metrology in quality systems, led to a widespread evaluation of measurement uncertainties based on the GUM uncertainty framework (Guide to the Expression of Uncertainty in Measurement). This methodology, however, has its own restrictions among which one could include the use of LRA in multi-stage measurement. To overcome these restrictions, an alternative...
XVIII IMEKO World Congress
· TC21
· 2006
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Wilhelm Kolaczia
In the field of metrology it is common practice to approximate the results of a measurement by functions modelling physical facts. The most simple form of such an approximation is the linear fit. This article presents five different methods of linear fit in R 2 by working out the characteristic features of these methods like scale unit invariance. The author's intention is to be helpful in finding the most useful method from case to case.
XVIII IMEKO World Congress
· TC21
· 2006
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Adriana Hornikova, William F. Guthrie
Key comparisons are international interlaboratory studies used to establish the degree of equivalence between national measurement standards. These studies, carried out by National Metrology Institutes (NMIs), are time-consuming, but necessary to facilitate international trade. From the signing of the Mutual Recognition Arrangement (MRA) in 1999 through the end of 2004, 85 key comparisons in a wide range of metrological areas were completed and have results posted in the Key Comparison Database (KCDB) maintained by the BIPM in France and in the International Comparisons Database (ICDB)...
XVIII IMEKO World Congress
· TC21
· 2006
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Roman Flegar, Tanasko Tasić
Applications of modern, computer (software) controlled measuring systems are various, from automation of testing and calibration laboratories to legal metrology measuring instruments and systems. Requirements to be met by such instruments or systems are usually defined by national or international legislation or international technical, safety, or laboratory competence standards. Validation of fulfilment of these requirements is essential for the conformity assessment of these instruments and systems. The complexity of validation and resources needed in the validation process depend on the...
XVIII IMEKO World Congress
· TC21
· 2006
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Paulo R. G. Couto, Jailton C. Damasceno, Renata M. H .Borges
The limitations presented by the ISO-GUM 95 methodology can by bypassed by applying Monte-Carlo simulation on measurement uncertainty estimation. In this work, uncertainty results from tensile strength, torque and Brinell hardness measurements evaluated using ISO-GUM 95 recommendations, Monte-Carlo simulation and the EURACHEM numerical simulated method are compared and discussed.
XVIII IMEKO World Congress
· TC21
· 2006
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Andrzej Miękina, Roman Z. Morawski
The paper is on the usefulness of global optimization for developing variational algorithms of spectrophotometer calibration. A new nonlinear method for reconstruction of absorption spectrum, on the basis of spectrophotometric data, is proposed and used for demonstrating that the quality of reconstruction depends on the ability of the calibration procedure to reach a global minimum during optimization of the parameters of the operator of reconstruction. The results obtained using calibration algorithms based on local and global optimization are compared in terms of measurement uncertainty...
XVIII IMEKO World Congress
· TC21
· 2006
· Download