IMEKO Event Proceedings

Page 3 of 770 Results 21 - 30 of 7695

Jörg Seewig, Tobias Hercke
2nd GENERATION LEAD MEASUREMENT

Typically, a car has over 80 dynamically stressed seals. Since many years, the radial seal in combination with the shaft is a critical component for the automotive industry. A helix-like structure due to the manufacturing process (as a fingerprint of said process) can lead to an unacceptable oil consumption. In collaboration with Daimler, an objective method for characterising such function-relevant helix-structures better known as lead was developed. The lead parameters, which are relevant to leak-tightness, are derived from a least square fit of complex exponential functions in both directions radial and circumferential. The basic measurement setup consists of a stylus instrument in combination with a rotation unit.

Baris Çal, Sinan Fank, Hakan Ö. Özbay, Ercan Pelit, Cihan Kuzu, Bülent Aydemir
3 MN HYDRAULIC TYPE BUILD-UP FORCE STANDARD MACHINE INSTALLED AT NATIONAL METROLOGY INSTITUTE (UME)

A new hydraulic type build up force standard machine with a 3 MN loading capacity both in tension and compression modes is installed in Force Measurment Laboratory of UME. The machine is designed and manufactured by ÖZMAK Manufacturing Company according to the technical specifications outlined by UME.
The performance test results show that relative measurement uncertainty of a new 3 MN build-up machine of UME is better than 4·10-4.

M. H. Orhan, Ç. Dogan, H. Kocabas, G. Tepehan
3-D FINITE ELEMENT MODELLING OF A HIGH PRESSURE STRAIN GAUGE PRESSURE TRANSDUCER

The scope of this study is a review of the studies on the pressure transducers designed at the TÜBİTAK-UME by utilizing Finite Element Method (FEM) for stress and strain analysis to optimize the design parameters prior to the construction of the pressure transducer prototypes. The constructed and investigated pressure transducer, has a free hardened AISI 4340 steel active element. Hydraulic gauge pressure is applied to the inside and both open ends of this active element. The FEM analysis was conducted by investigating one half of the element in three dimensions and realized at three different pressure values of 60, 100 and 150 MPa. This study presents the FEM output stress and strain values. The validity of those values was established by comparing them with the results obtained from the strain gauge measurements. The relative difference between the two value sets was determined as being lower than 13% of the full scale. The presented results will be helpful for the appropriate design of this kind of pressure transducers using FEM.

David I. Serrano-Garcia, Yukitoshi Otani
3-D SURFACE PROFILOMETRY EMPLOYING THE POLARIZATION PHASE SHIFTING TECHNIQUE

Optical measurement techniques have become indispensable tools in many areas of science and engineering. The whole-field, non-contact and highly accurate measurement are among the principal features of these techniques. The purpose of this research is to analyze the case when the sample under study presents polarization properties, as retardance or diattenuation. The use of phase shifting modulated by polarization has the advantage of not requiring mechanical components, such as a piezoelectric transducer (PZT), to obtain the phase shifts. The main purpose of introducing polarization phase shifting techniques, added with replication systems, is to collect all the phase-shifted data in a single exposure in order to minimize time-varying environmental effects. When the sample under study changes the polarization properties of the object-beam, errors associated at the contrast and phase shift values on the final interferogram are obtained. The main purpose of this work is to find a suitable model in charge to modelate when the sample presents polarization properties as retardance or diattenuation. A model based in find a Mueller matrix of the polarization phase shifting interferometer is introduced in order to settle the basis for a non-ideal model.

Wirun Laopornpichayanuwat, Jakkapol Visessamit, Montian Tianprateep
3-D SURFACE ROUGHNESS PROFILE OF 316-STAINLESS STEEL USING VERTICAL SCANNING INTERFEROMETRY WITH A SUPERLUMINESCENT DIODE

Surface roughness is one of many parameters that influences on mass stability of standard weight, commonly used as a transfer standard of mass SI unit. One of the most famous non-invasive methods for determining surface roughness from a surface profile of material is a vertical scanning interferometry (VSI) with a white light source. In this research, 3-D surface profiles of 316-stainless steel, usually used as a material for standard weights, are constructed by using VSI, based on Michelson interferometer (MI). Because of its low-coherent properties, low cost, and compact light source, a superluminescent diode (SLD) is chosen as a low-coherence light source in our interferometry system. Since a continuous wavelet transform (CWT) algorithm provides accuracy results, it is also used as a numerical analyzing method for the interferogram signals, taking from our VSI. The surface roughness and measurement uncertainty, calculated from the constructed 3-D surface roughness profiles of 316-stainless steel samples, are discussed.

Takashi Takuma, Shinji Yabushita, Takeshi Kawajiri, Kana Yanogawa, Takaki Harada, Kazuya Yamamoto, Ichirou Ishimaru
3-DIMENSIONAL SPECTROSCOPIC-TOMOGRAPHY OF BIOLOGICAL MEMBRANE BY THE IMAGING-TYPE 2-D FOURIER SPECTROSCOPY

We proposed the imaging-type 2-D Fourier spectroscopy that is the phase-shift interferometry between the objective lights. The proposed method can measure the 2-D spectral image on the focal plane. We construct the proposed method by the infrared radiation optical system to try to apply for the noninvasive measurement of the blood glucose level. In this report, we discuss about the spectroscopy method to measure the vessel area of the proximal skin surface that is little affected by the diffusion cased by the biological membrane. The proposed method is constructed with Fourier spectroscopy with high wavenumber resolution. Therefore, the proposed method can measure spectroscopy of greenhouse gases and noxious fumes with narrowband width of spectral adsorption index. In this report, we mention the principle of the imaging-type 2-D Fourier spectroscopy and the development of the 2-D spectroscopic measurement for unstructured environment.

C.Donciu, O.Costea
3D E-SHADE DENTAL COLOR MATCHING INTELLIGENT SYSTEM

Shade matching is a much complicated task then it may look like. Variability of the factors which influence the shade matching procedure should be minimized. There is a need for a new, better, logically and scientifically arranged shade guide which would cover the complete color range of natural teeth. The project proposes to accomplish a color prosthetical establishing performing system through image processing methods by using cumulative informations concerning chromatic analysis and also the transparency variation depending on work’s 3D geometry. By realizing a bidirectional communication routine on a cable support dentist office- dental technician laboratory it is facilitated the establishing of the acquired information volume and quality sufficiency, on the one hand, and on the other hand the prosthetical work delivery programming depending on the material and human resources available in the dental technician laboratory.

Karl J. Lenz
3D HIGH SPEED HIGH ACCURATE LASER MEASUREMENT ON SHINY SURFACES WITHOUT SPRAYING

The majority of industrial surfaces is optically not cooperative and is difficult or not possible to be measured optically. This forces customers to use slow tactile measurement methods. Today surfaces are made optically cooperative by spraying some powder. This method is not economical (takes additional preparation time) and is not accurate (the sprayed layer thickness is unknown). The presentation will explain how optically non cooperative industrial parts can be conditioned for optical high accurate, high speed measurements. The presentation will explain the conditions for the expected substantial increase of optical high speed sensors for dimensional inspection

Yu. V. Chugui, E. S. Senchenko
3D IMAGE FORMATION IN TRANSMITTED PARTIALLY COHERENT AND INCOHERENT LIGHT APPLIED TO DIMENSIONAL INSPECTION

The peculiarities of 3D objects image formation with clear shadow projection under their illumination by partially coherent and perfectly incoherent light based on the constructive theory of 3D objects formation are investigated. Threshold algorithms for determining the position of 3D object geometric boundary, taking into account its thickness, the light source angular size and the projection system angular aperture are developed. These algorithms are based on the application of true (calculated) threshold or standard one using the corrective component for threshold. The cases of weak and strong 3D object volumetricity for partially coherent and incoherent illumination are studied. The analytical equations for these algorithms are given. It has been shown that their use can significantly improve the measurement accuracy of extended objects.

Roberto Cesareo, Stefano Ridolfi, Antonio Brunetti, Ricardo T. Lopes, Giovanni E. Gigante
3D Imaging of Paintings by Scanning with a Portable EDXRF-Device

3D map of chemical elements distribution from energy dispersive X-ray fluorescence (EDXRF) analysis would be a perfect conclusion to study in detail any type of artifact. This map can be easily achieved by using synchrotron light as source of radiation, and micro-optics both at the source and at the detector. In such a manner a micro-voxel is irradiated and detected, which can be at any depth with respect to the surface of the artifact. This method is effective but needs a synchrotron; therefore its use in archaeometry is greatly limited. An alternative method is proposed in the present paper, which uses the altered Kα/Kβ or Lα/Lβ-ratios to localize the chemical elements. This method employs a portable EDXRF-device, characterized by a small size X-ray tube and a Si-drift detector. Several examples are described.

Page 3 of 770 Results 21 - 30 of 7695