Universität Stuttgart
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Item Open Access Optical methods of measuring rough surfaces(1989) Leonhardt, Klaus; Rippert, Karl-Heinz; Tiziani, Hans J.The statistical parameters of surfaces to be measured for industrial applications vary over several orders of magnitude. Surfaces with large slopes or edges are particularly difficult to be recorded. Some measuring methods developed in our laboratory are compared and the range of applications are discussed. For polished and fine ground glass and metal surfaces a heterodyne profilometer with a vertical resolution of 0.5 nm, lateral resolution of 0.6 μm, and large scanning length is discussed. The interferometer can be changed from single- to double-pass operation by rotation of a quarter-wave-plate. For rougher surfaces a profilometer of the photometric-balance type with resolution Rq < 4 nm and dynamic range of 20 μm and an interference microscope with automated fringe evaluation is described. An integral white light roughness sensor covers the roughness range 0.04μm to 10μm and measures independently mean roughness and autocorrelation width.Item Open Access Holographic interferometry and speckle metrology : a review of the present state(1983) Tiziani, Hans J.The review paper will describe the present state of holographic and speckle techniques as applied to industrial measurement. The basic principles of both techniques will be outlined with special attention given to their advantages and limitations. Current developments in the field will then be described including the testlng of rotating automobile tyres by holographic interferometry and a heterodyne technique to gain an insight into noise generation mechanism. Methods for real-time holographic and speckle recording to facilitate the use of the techniques in an industrial situation will be discussed.Item Open Access Optical 3-D-measurement techniques : a survey(1989) Tiziani, Hans J.Close range photogrammetry will be more frequently applied in industry for 3-D-sensing when real time processing can be applied. Computer vision, machine vision, robot vision are in fact synonymous with real time photogrammetry. This overview paper concentrates on optical methods for 3-D-measurements. Incoherent and coherent methods for 3-D-sensing will be presented. Particular emphasis is put on high precision 3-D-measurements. Some of the work of our laboratory will be reported.Item Open Access Application of interferometry and holography for precision measurements(1984) Tiziani, Hans J.Phase measurement techniques are becoming a useful tool for precision measurements. Spatial as well as temporal phase shift methods can be used. Optical testing, where computer analysis of interference fringes is becoming increasing important, will be discussed in connection with testing optical components, microprofiles as well as for testing aspheric surfaces. In addition, methods using heterodyne techniques and real time holography will be described.Item Open Access Mikro-Profilometrie zur Bestimmung der Topographie und Rauheit technischer Oberflächen mittels Heterodyn-Laserinterferometrie(1989) Leonhardt, Klaus; Rippert, Karl-Heinz; Tiziani, Hans J.Ein Heterodyn-Profilometer zur Messung der Rauheit polierter und feingeschliffener Oberflächen und zur Formmessung wird beschrieben. Die Vertikal- oder Höhenauflösung liegt bei 0,5 nm, der Meßbereich für Formmessungen an glatten Oberflächen bei 40 pm bei einer maximalen Abtastlänge von 300 mm. Die Lateralauflösung kann je nach Aperturausleuchtung bis zu 0,5 pm eingestellt werden. Anwendungen und Grenzen werden gezeigt, Formeln zur Lateralauflösung und zur Erfassung von Phasensprüngen sowie Profilhöhen-Übertragungsfunktionen werden diskutiert.Item Open Access Remote nondestructive material analysis by photothermal interferometry(1987) Sodnik, Zoran; Tiziani, Hans J.Interferometry is used for the detection of thermal waves to study material properties. A symmetrical interferometer as thermal expansion detector was developed for photothermal nondestructive material analysis. After mixing a phase shifted reference signal electrically to the interferometer signal, phase and amplitude exchange phenomena have been observed.Item Open Access Current state of optical testing(1987) Tiziani, Hans J.Basic interferometry and holographic interferometry are becoming useful tools for precision measurements. The use of electronic solid state detector arrays, together with small computers for extracting the information from the interferograms improve their applications. Computer analysis is becoming increasingly important. A lot of information can be extracted from the interferograms leading to higher sensitivities and accuracies.Item Open Access Heterodyn-Speckle-Interferometrie zur Schwingungsmessung(1987) Jahn, Gerald; Tiziani, Hans J.Eine Kombination aus Speckle-Interferometrie und Doppler-Yelocimetrie ermöglicht die Messung von Schwingungen bzw. Geschwindigkeiten an rauhen Oberflächen an mehreren Punkten gleichzeitig. Wir nennen dieses Verfahren Heterodyn-Speckle-lnterferometrie. Das Messprinzip ist das der Laser-Speckle-Interferometrie, die durch Einführung einer Lichtfrequenzverschiebung im Referenzstrahl dynamisiert wird. Dem Speckle-Bild des Messobjekts wird die Referenzwelle überlagert, gemessen wird die Frequenz der Intensitätsänderung in bestimmten Punkten des Bildes.Item Open Access Echtzeitholografie mit BSO-Kristall zum Messen der Schichtdickenänderung beim Aushärten von Zwei-Komponenten-Klebstoffen(1987) Pfister, Berthold P.; Tiziani, Hans J.Die Präzisions-Klebeverbindungen empfindlicher Bauteile können infolge der Schichtdickenänderung des Klebstoffs beim Aushärten (Schwinden) neben maßlichen Veränderungen auch erhebliche Spannungen und daraus resultierende unzulässige Bauteildeformationen auftreten. Um die Schichtdickenänderung quantitativ erfassen zu können, sind insbesondere berührungslos messende Verfahren geeignet, da die Messungen während des Aushärtens des Klebstoffes, d.h. in seiner "flüssigen Phase" erfolgen müssen. Unter bestimmten noch zu erörternden Voraussetzungen bietet sich die Echtzeitholografie an, diese Meßaufgabe zu lösen.Item Open Access Dual wavelength heterodyne interferometry for rough surface measurements(1990) Fischer, Edgar; Sodnik, Zoran; Ittner, Thomas; Tiziani, Hans J.For interferometric topography measurements of optically rough surfaces dual wavelength heterodyne Interferometry (DWHI) is a powerful tool. A DWHI system based on a two-wavelength HeNe laser and a matched grating technique is described. This set-up improves system stability and simple heterodyne frequency generation.
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