Vladimir Pašagic, Tijana Parlic Risovic
Althought the surveying instruments grow ever more complex, yet the telescope remains the basic part of modern-day surveying instruments. When considering the problem of measuring with a surveying instrument, that is with the telescope, it is necessary to consider the issue as a whole. In other words it is necessary, alongside the function of the telescope, to take into consideration the object to be measured, atmosphere as the medium transmitting light and physiological and psychological attributes of the sighter. In order to define a complex optical system that would facilitate prediction...
XVII IMEKO World Congress
· TC2
· 2003
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Erik Novak, Joanna Schmit
White light interferometry has become a common tool for measuring surfaces with large height ranges, slopes, and large roughness. The object is generally scanned through focus, varying the optical path difference between the light reflected from the object and from a secondary reference surface. The quality of the measurement is dependent on having a known and constant- velocity scan, as well as knowing the effective wavelength of the white light source at all times. In this paper we present a white light interferometer with an embedded second interferometer utilising a HeNe laser which...
XVII IMEKO World Congress
· TC2
· 2003
· Download
Erik Novak, Der-Shen Wan, Paul Unruh, Michael Schurig
Accurate measurements of MEMS surfaces, geometries and motions are crucial to achieving the desired performance of the devices. The wide variety of MEMS devices in development and production requires very flexible metrology for single-platform characterization. In addition to having greatly varying geometries, devices must also be characterized statically and under actuation. White-light interferometry, fortunately, is a technique flexible and accurate enough to meet MEMS metrology needs. This high-speed, non-contact measurement method allows both large lateral and vertical ranges with...
XVII IMEKO World Congress
· TC2
· 2003
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Leonardo D’Acquisto, Roberto Montanini
When compared with traditional electrical strain gauges used for strain monitoring, Fibre Bragg Grating (FBG) sensors have several distinguishing advantages that make them very attractive for many applications in different fields. Nevertheless, for practical applications, their metrological performance needs to be assessed under different operative conditions. In this paper attention has been focused on the response of FBGs when glued on a metallic surface that is not flat. Hollow-tube specimens with two different curvatures have been considered, together with a plane specimen used as...
XVII IMEKO World Congress
· TC2
· 2003
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Consolatina Liguori, Alfredo Paolillo, Antonio Pietrosanto
In this paper a parametric model of the uncertainty of digital images in industrial contest is presented and characterized. The functional dependency of the model parameters from the operating conditions and the image characteristics are theoretically established and experimentally verified.
XVII IMEKO World Congress
· TC2
· 2003
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Pal Greguss , Edith Greguss
Panoramic Annular Lens based Attitude Measurement sensor combined with Ground Imager (PALAMGI) for satellites. There is a need of miniaturized platform elements of spacecrafts, especially for nano and micro satellites programs. A single unit is proposed instead of two separate ones using the newly developed Humanoid PAL vision system.
XVII IMEKO World Congress
· TC2
· 2003
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Marta Valledor, Juan Carlos Campo, Miguel A. Perez, Juan C. Alvarez, Juan C. Viera
Phosphorescent sensors are usually based on measurement of light intensity or lifetime of sensor emitted light. This goal may be accomplished by measuring the phase-shift between the excitation and the emitted light. Scattered signals must be removed to perform the measurement; however, some of the scattered light due to fluorescence is impossible to remove when measuring phosphorescence decay times. In this paper, a new method to measure lifetime in the presence of fluorescence light emitted by the phosphorescence sensor is presented. This method is based on the measurement of the...
XVII IMEKO World Congress
· TC2
· 2003
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Wolfgang Holzapfel, Nejat Mahdavi, Martin Suske
A novel laser accelerometer is introduced, its physical principle and main characteristics are explained, and preliminary experimental results are presented. The accelerometer utilizes two Nd:YAG laser crystals and a common proof mass which operate in push-pull mode. The main advantages of the described laser accelerometer are wide measuring range which covers 9 decades up to 100 m/s², very high linearity over measuring range and excellent dynamics (20 kHz bandwidth). In comparison to servo accelerometers, these results represent a high-performance sensor. The measurement uncertainty and...
XVII IMEKO World Congress
· TC2
· 2003
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Andrea Cataldo, Bahram Nabet, Adriano Cola, Amerigo Trotta
In this paper we describe the characterization of a family of optical devices based on heterojunction and heterodimensional structures and we investigate their static and dynamic properties. Such devices are good candidates, due to their high performance, for utilization as the sensing element for the realization of sensors in the fields of telecommunications, remote sensing, LIDAR and medical imaging. First, we present a Heterostructure Metal-Semiconductor-Metal (HMSM) photodetectors that employ a uniformly doped GaAs/AlGaAs heterojunction for the dual purpose of barrier height enhancement...
XVII IMEKO World Congress
· TC2
· 2003
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Christof Bosbach, Tilo Pfeifer, Frank Depiereux
White light interferometry or coherence radar is a well known and established measurement technique for years. But especially the field of production technology and medical technology need measurement systems with continuously increasing performance. This paper demonstrates, how the use of special optical components for higher measurement frequencies and the miniaturizing of the sensor tip can enlarge the application fields for this system. First, the fundamental aspects of white light interferometry are presented and lead to the new concept of a distance measurement system. It is shown how...
XVII IMEKO World Congress
· TC2
· 2003
· Download