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Andrea Magalini, David Vetturi
LASER INTERFEROMETRY FOR STRAIGHTNESS MEASUREMENTS IN A WEAKLY CONTROLLED ENVIRONMENT

Straightness measurements for the geometrical inspection of machining tools have been operated in a weakly controlled environment (concerning temperature, pressure, humidity and induced mechanical vibrations) with reference to industrial manufacturing departments.
Measurements have been performed by means of a Wollaston prism laser interferometer.
A first experimental characterization of this instrumentation has been operated by repeatability tests conducted in controlled and not controlled environments, considering different relative positions for the interferometer and the laser head. Then a calibration diagram has been constructed, assessing the accuracy and the instrumental uncertainty in the case of displacement measurements in a plane perpendicular to the laser beam direction.
In a second stage a suitable method has been developed to estimate the uncertainty level associated to straightness measures operated by the laser interferometric technique and also by traditional instrumentation, such as taut-wire and microscope and precision level. Measurement uncertainty is estimated by means of the Monte Carlo Method and according to standards.
Measures obtained by the laser interferometric method prove to be affected by higher levels of uncertainty than those coming from traditional approaches.

Alexandre Titov, Igor Malinovsky
ADVANCES AND NEW TECHNIQUES IN LENGTH MEASUREMENTS BY OPTICAL INTERFEROMETRY

Studies of a long gauge block Kösters interferometer, performed at INMETRO, and the results of the CIPM Key Comparison CCL-2 show that the uncertainty in realization of the SI length unit achieved with this type of instrument in the range of 500 mm is ~1 part in 108. Basic advances in philosophy and techniques of high-precision temperature measurements, realized in Brazil in the last few ears, permit to reduce crucially the uncertainty of length measurements by optical interferometry and to reach the Nanometrolgy regime in artifacts with nominal lengths above 100 mm. New measurement and calibration techniques give an opportunity to realize the temperature measurement of a particular point on the GB surface inside the interferometer with a total uncertainty below 0.1 mK, realizing the measurement without the contributions of the temperature gradient in the GB and velocity error. The demonstrated reproducibility in length measurements of 100-mm steel gauge block is at the level of 58 pm.

Olga B. Basun, Valery A. Granovsky, Mikhail D. Kudryavtsev
PRECISION SCALES OF PLANE ANGLE: PRINCIPLES AND METHODS OF CALIBRATION

Precision angular scales are considered from common point of view, and principles of their construction are formulated. Methods of mutual calibration of circular scales are developed to meet these principles taking into account the redundancy factor. Multidimensional classification of the methods is proposed. The family of designs is constructed, and relations of procedure parameters of a scale carrier calibration with required accuracy of the procedure results is established.

J. Sładek, R.Sitnik, M. Kupiec, P.Błaszczyk
THE NEW HYBRID METHOD FOR FAST AND PRECISION MEASUREMENT

In this article a new concept of a hybrid measurement method will be presented. The hybrid method is developed for fast and precise measurement especially for the automotive industry. It combines the high-speed of optical methods with the high-accuracy of CMMs measurement. A laboratory prototype of the system is described. Furthermore we present preliminary work on assessment of measurement uncertainty of the hybrid system based on the comparison of the results with CMM measurements.

José Sánchez, Sergio Padilla, J.M. Dorador
NEW FACILITIES OF VIRTUAL MACHINES: OPERATING MACHINES FROM CAD BROWSERS, FOR ANALYSIS

The main purpose of this paper is to show advances on the concept of virtual coordinate machines, already developed for aiding calibrating and teaching tasks. It is now possible to operate these machines directly from CAD browsers. No matter how distorted are the machines, it is possible to perform the analysis.

Yuri Chugui, Sergei Plotnikov, Anatoly Potashnikov, Alexander Verkhogliad
3D MEASURING TECHNOLOGIES FOR INDUSTRIAL AND SCIENTIFIC APPLICATIONS

The novel results of the R & D activity of TDI SIE SB RAS in the field of the optical measuring technologies, as well as laser technologies for solving safety problems are presented. To measure the rocks stress and to prevent the mountain impact, as well as for basic investigations, a set of optical-electronic deformers and systems was developed and produced. For permanent noncontact bearing position inspection of oil-drilling platforms on Sakhalin coast (Russia) we have developed optical-electronic method and system SAKHALIN. Multifunctional laser technological system LSP-2000 equipped by two Nd-YAG lasers was developed for cutting, welding and surface micro profiling with ablation process (working range of 3 x 2 x 0.6 m³, positioning error less than 10 mkm). Results of development and testing the specialized high productive laser measuring machine, based on structured illumination, for 3D inspection of grid spacers for Russian nuclear reactors with micron resolution are presented. Using high-speed laser noncontact method on the base of triangulation position sensors, TDI SIE has developed and produced automatic laser diagnostic system COMPLEX for inspection of geometric parameters of wheel pairs (train speed up to 60 km/hr.), which is used successfully on Russian railways.

Flávia Pompéia, Luiz A. P. Gusmão, Carlos R. Hall Barbosa, Elisabeth Costa Monteiro, Lídice A. P. Gonsalves, Fernando L. A. Machado
CHARACTERIZATION OF A MAGNETIC FIELD TRANSDUCER BASED ON THE GMI EFFECT

A magnetic field transducer based on the giant magnetoimpedance (GMI) effect has been developed by the Laboratory of Biometrology at PUC-Rio. It is aimed at biomedical applications, especially three-dimensional localization of needles accidentally inserted in the human body. This manuscript presents some new measurements that led to a better understanding of the prototype’s behavior.

Ireneusz Jabłoński, Janusz Mroczka
MEASUREMENT – MODELING, MODELING – MEASUREMENT: A TRANSITIVE COUPLE OF REALITY AND ABSTRACTION IN EQUIPAGE OF COMPREHENSION AND PREDICTION FOR EXAMPLE OF BREATHING CONTROL

The paper presents the problems of modeling and measurements in the medical sciences in the context of a dynamical system theory. Modeling can be seen here not only by the optics of a concrete object – system of breathing control, but first of all by the features of the tools used during reality reconstruction, which directly transfer to measurement procedure. The article is an introduction to a given research area.

Ireneusz Jablonski, Janusz Mroczka
INTRODUCTION TO RESPIRATORY MECHANICS MEASUREMENT BY ENHANCED INTERRUPTER METHOD

In the paper, there are postulated the basic requirements for the effective modification of a standard scheme of the interrupter technique (IT). The new method dedicated to respiration mechanics measurements, which meets such assumptions, is called enhanced interrupter technique (EIT). Using the idea of indirect measurements, it was showed by computer simulations the possibility to estimate the more number of parameters in EIT than in IT (only airway resistance Raw) for the proposed, modified Dubois’ model. EIT gives the higher accuracy and the reduced dispersion of the measurement results, at the same time. As it follows from the computer simulations, analysing the measurement data in the time domain and the use of as quick as possible occlusion valve (occlusion needs to include both the sudden, postocclusional transient states and the slow rise of the pressure at the mouth Pao) is essential to optimize EIT from the metrological point of view. The worked out problems are a base to construct a portable device, dedicated to measurement of the mechanical properties of the respiratory system.

T. M. Almeida, M. S. Piedade, P. C. Lopes, L. Sousa, J. Germano, F. Cardoso, H. A. Ferreira, P. P. Freitas
MAGNETORESISTIVE BIOSENSOR MODELLING FOR BIOMOLECULAR RECOGNITION

This paper presents the modelling of a magnetic biosensor included on a hand held microsystem based on a fully integrated magnetoresistive biochip for biomolecular recognition (DNA hybridisation, antibody antigen interaction, etc.). The biochip uses magnetic field arraying of magnetically tagged biomolecules and high sensitivity sensors which can be used to detect single or few biomolecules. The biosensor has an matrix-array structure and each biosensor site consists of a thin film diode in series with a magnetic tunnel junction. Schottky and pin diodes are used as temperature sensors and switching devices, although this paper specially emphasises pin diodes characterisation. A complete theoretical model characterising biosensor electrical, temperature and magnetic behaviour is derived and experimental results are provided.

Page 851 of 938 Results 8501 - 8510 of 9371