Jan Maschke, Èestmír Vlèek, Ladislav Ševèík
Paper deals with measurement of polarization properties of fibers along incidence of different external effects as temperature, torsion and magnetic field. Study of polarization is important from the polarization dispersion point of view for communication systems and also in the area of interferometric and polarization sensors or general interferometric measurements. Analysis of individual effects is solved theoretically and practically in the series of works. Our contribution solves a relatively short part of fiber, where additionally fluctuation of power between both polarization modes...
XVII IMEKO World Congress
· TC2
· 2003
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Sami Asikainen, Marko Loisa, Juha Kortelainen, Veikko Seppälä
This paper gives an introduction to the imaging in process analysis. The analysed process, where the images are taken from, is the second stage pulp refining process in TMP-plant. Either the images or the analysed features of the images are compared with the process data. The obtained results show that changes in process variables have effect on the images.
XVII IMEKO World Congress
· TC2
· 2003
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Jarkko Unkuri, Jorma Manninen, Antti Lassila
In precision length measurements the accurate and traceable value of the linear thermal expansion coefficient (LTEC) is needed. A device for interferometric determination of the LTEC of gauge blocks has been constructed. Minimum temperature gradients in a gauge block with 500 mm maximum length and relatively fast operation were the objectives of this project. Based on uncertainty analysis LTEC can be measured with a standard uncertainty of 0,02·10 -6 1/K for 100 mm gauge blocks.
XVII IMEKO World Congress
· TC2
· 2003
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D. Doerner, A. Bai, P. Mangalasseril, T. Pfeifer
Interferometry is a common method for testing the form of ultra-precise components. However interferometrical measurements are very sensitive to external influences. Due to this reason, in-situ measurements are very difficult to perform, especially in the vicinity of production processes. In this paper we present a new concept for the integration of interferometers in a machine tool and first results of the analysis of fundamental influences on interferometers operated in-situ.
XVII IMEKO World Congress
· TC2
· 2003
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Damir Veza, Marc L. Salit, John C. Travis, Craig J. Sansonetti
We have investigated the intrinsic accuracy of the optical frequency scale in spectra acquired by a Fourier Transform Spectrometer (FTS). The uncalibrated accuracy of the FTS optical frequency axis is about 1 part in 10 5 . This uncertainty can be reduced by at least two orders of magnitude using a multiplicative calibration correction derived from a single wavelength standard line. The work reported here describes a new approach to accurate calibration of the wavenumber scale for a UV-visible FTS, which we have used to measure accurate wavenumbers and Ar pressure shifts for the prominent...
XVII IMEKO World Congress
· TC2
· 2003
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Edgar Scherleitner, Bernhard G. Zagar
An approach of a diffuse optical tomography system using NIR wavelengths will be presented to image heterogeneities in various kinds of turbid volumes, such as a wide range of biological substances, many translucent technical substances like plastics, foams and fluids. A light intensity modulation technique is employed to achieve imaging of the absorption and additionally even the scattering properties of superior resolution than usual transillumination images of technical process monitoring. Since the understanding of photon migration in strongly scattering media has improved much lately,...
XVII IMEKO World Congress
· TC2
· 2003
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Rainer Riesenberg, Andreas Wuttig
Experimental results of intelligent adaptive detection made with spectral sensors are presented. Firstly for a commercial detector array spectrometer the single entrance slit is replaced by a slit array. Differently patterned one-dimensional arrays are used. There are switched and fixed versions of arrays. An improvement of the detected signal and the signal-to-noise-ratio by the factor 10 has been achieved. Secondly the measured noisy signal is compared with known expected signals. Weak signals can be detected with an high probability and thus an increased sensitivity.
XVII IMEKO World Congress
· TC2
· 2003
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Hiromitsu Tsutsu, Ichirou Ishimaru, Fumikazu Oohira, Kenji Hirata, Fumio Sirai
The purpose of this study is establishment of the high precision transmittance measurement technology (accuracy: 0.01%) of the large diameter lens(material: CaF 2 , diameter: 200mm) for ultraviolet rays (wavelength: 193 nm). Transmittance measurement method with photoacoustic spectroscopy is proposed. This technology depends on only photothermal spectroscopy at a local minute area and is independent of lens size. So this proposed method can be applied to large diameter lens. And measurment time at one point is extremely short. So the superiority of this new method is that the transmittance...
XVII IMEKO World Congress
· TC2
· 2003
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D. Stifter, P. Burgholzer, O. Höglinger, E. Götzinger, C. K. Hitzenberger
We apply optical coherence tomography (OCT) and a modification thereof, namely polarisationsensitive OCT (PS-OCT), to a variety of problems posed in metrology for material analysis and diagnostics. Among these are imaging of glass-fibre enforced epoxy resin compounds and the detection of dry spots. Furthermore, PS-OCT measurements have been used to measure the birefringence and the orientation of the fast optical axis within test structures: mapping of strain fields of samples under uni-axial and non-uniform external stress and the detection of flow patterns in injection-moulded plastic...
XVII IMEKO World Congress
· TC2
· 2003
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Anselmo S. Paschoa, Felipe L. C. Moutella, Max T. Facchinetti, Luis A. T. Rovere, Olga Y. Mafra, Heitor Evangelista
The need for determining the 235 U/ 238 U ratio in environmental and biological samples is increasing, mostly after the Gulf War and the conflit on the Balkans. This paper describes a simple way to calibrate a low gamma counting system for measuring depleted, natural, and low enriched uranium.
XVII IMEKO World Congress
· TC2
· 2003
· Download