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Copyright of Technisches Messen is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Technisches Messen is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Acceleration sensors for structural health monitoring of engineering structures under the influence of environmental factors at low frequencies Structural health monitoring (SHM) is increasingly used to continuously assess the condition of engineering structures. Important assessment parameters are global system properties, such as eigenfrequency, which are measured by accelerometers. micro‐electro‐mechanical systems (MEMS) sensors are often used, but have a high noise level. Alternatively, low‐noise IEPE (integrated electronics piezo electric) sensors can be used, which reliably detect vibrations even with the slightest structural excitation. Another problem is that changes in eigenfrequency due to structural damage are difficult to distinguish from changes in eigenfrequency due to environmental effects. The latter change the properties of both the structure and the measurement system. In order to investigate environmental effects on the measurement system in the field of civil engineering, IEPE accelerometers have been analyzed for their transmission behavior in the low‐frequency acceleration range. It was found that the behavior is not only frequency dependent, but also temperature dependent, while humidity has no influence. These nonstructural effects must be compensated for to ensure robust condition monitoring. IEPE sensors are recommended for civil engineering applications because of their high signal‐to‐noise ratio and ability to reliably detect low‐frequency structural vibrations. [ABSTRACT FROM AUTHOR]

Copyright of BHM Berg- und Hüttenmännische Monatshefte is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Technisches Messen is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Technisches Messen is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Technisches Messen is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Technisches Messen is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Technisches Messen is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Technisches Messen is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Technisches Messen is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Technisches Messen is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Technisches Messen is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Several different formulations of the general form HT ht have been proposed in the literature and are reviewed by Van der Grinten et al. [[25]]. The obtained parameters HT ht {a {1}}, to HT ht {a {7}} are valid only for tested gas meter. This also means that the expanded measurement uncertainty of the relative error HT ht must not exceed 0.5 %. Mathvariant="italic">x2+Bx+C+D-x+D-x2 ht \displaystyle E=\frac{A}{{x^{2}}}+\frac{B}{x}+C+D\cdot x+D\cdot {x^{2}} (A4) 5. [Extracted from the article]

Calibration method for constant strands of material with robot‐assisted concrete extrusion Robot‐assisted concrete extrusion is a complex, new type of additive manufacturing process in which strategy, material and conveyor system must be specifically coordinated with one another. In particular, the real shape of the extruded material strand is subject to significant fluctuations along the starting point, via the main extrusion phase, until the switch‐off process due to local over‐ and under‐extrusions, which usually do not meet the quality requirements. In this work, an efficient calibration process is used to develop the calibration method for the extrusion process according to the algorithm developed, to adjust and test it on the software side, and to examine the effects of the feed rate on the component quality. In this article, the efficient calibration of the extrusion process according to the developed method is compensated on the software side and the effects of the feed rate on the component quality are investigated. For this purpose, different calibration methods of current additive manufacturing processes were considered and evaluated with regard to their usability for the extrusion of mineral suspensions. Building on this, a general procedure for calibration and its practical implementation was theoretically developed. In the function tests carried out the method reduced the process preparation, increased process reliability through the stabilized extrusion and shortened the cycle time. This increase in productivity in additive manufacturing allows the use of high‐strength lightweight structures in construction and enables the serial implementation of free‐form modular designs. [ABSTRACT FROM AUTHOR]

Copyright of Technisches Messen is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Technisches Messen is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Automatisierungstechnik is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Technisches Messen is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Technisches Messen is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Mit einem Multi-Punkt-Positionsmesssystem ist es möglich, Positionen und Orientierungen mit sehr hoher Genauigkeit bildbasiert zu messen. Das Messsystem besteht aus einem einfachen Kamerasystem, das um ein diffraktives optisches Element (DOE) erweitert wird. Durch die Multi-Punkt-Methode (MPM) werden Messunsicherheiten von deutlich unter 1/100 Pixel erzielt. Um dies in der Praxis anwenden zu können, ist eine entsprechend hochgenaue Kalibrierung nötig. In diesem Beitrag werden verschiedene Kalibrierverfahren und -funktionen vorgestellt und untersucht. Die Auswertung zeigt, dass sich zur Kalibrierung ein allgemeiner Polynomansatz zusammen mit der Nanomess- und Positioniermaschine NPMM-200 am besten eignet. Es werden Standardabweichungen des Restfehlers von 0,31 µm im Objektraum (etwa 6/1000 Pixel im Bildraum) auf einer Fläche von etwa 87 mm × 49 mm 87\hspace{0.1667em}\text{mm}\times 49\hspace{0.1667em}\text{mm} erreicht (Polynomgrad = 9). A multipoint position measurement system is an image based measurement system to detect positions and orientations with very high accuracy. It consists of a simple camera system that is extended by a diffractive optical element (DOE) to reach accuracies of less than 1/100 pixel. To use this method in practice, an accurate calibration is necessary. In this artircle we will introduce different calibration methods and -functions and investigate them. It is to be seen that calibration with a general polynomial in combination with the Nanomeasurement- and positioning machine NPMM-200 provides the necessary means to reach standard deviations in reprojection error of 0,31 µm in object space (approximately 6/1000 pixel in image space) in an area of 87 mm × 49 mm 87\hspace{0.1667em}\text{mm}\times 49\hspace{0.1667em}\text{mm} (polynomial order = 9). [ABSTRACT FROM AUTHOR]

Copyright of Automatisierungstechnik is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Seit dem 20. Mai 2019 gilt das neue Internationale Einheitensystem SI. Dies stellt eine Zäsur in der Geschichte der Einheiten dar, denn von nun an sind alle 7 Basiseinheiten durch Fundamentalkonstanten definiert. Gerade für die Masse und die daraus abgeleiteten Größen hat das weitreichende Folgen. Das Urkilogramm ist jetzt nur noch ein normales 1 kg-Wägestück. Der Gewinn aber ist enorm. Das Kilogramm lässt sich zukünftig für jeden Massewert darstellen und muss nicht mehr auf das Urkilogramm rückgeführt werden. Da die Kraft bislang über die Masse rückgeführt wurde, öffnen sich aber auch deren Definition neue Wege. In diesem Artikel soll beschrieben werden, wie die prinzipiellen Realisierungen des Kilogramms über die Kibble-Waage und die Röntgenkristalldichtemessungen (XRCD-Methode, oder auf Englisch X-ray-crystal-density method) funktionieren und welche Ideen für die Kraft-Messung bereits umgesetzt wurden. The new International System of Units SI is in effect since May 20th 2019. For the first time in the history of metrology, all seven base units are defined by fundamental constants. Notably, this implies major consequences on the mass and the units derived from it. From now on, the International Prototype of the Kilogram (IPK) is just a regular mass standard. The Kilogram can be represented independently from the nominal value of a weight and has not to be traced back to the IPK. Since the force was traced back to mass until the redefinition, there are new possibilities of traceability of force measurements now. This article presents the concepts of the primary realizations by a Kibble balance or the X-ray-crystal-density (XRCD) method and ideas that were utilized for force measurements. [ABSTRACT FROM AUTHOR]

Numerical simulation of passive earth pressure in sand and comparison with measurements in model tests. In the paper a finite‐element‐model is presented, adjusted by Hegert [1] to Bartl's model test device and verified in detail by the comparison of the coefficients of mobilised earth pressure, displacements in the limit state, surface displacements, local coefficients of earth pressure and the point of application of the resultant earth pressure. The measurements can be well simulated in consideration of the possibilities and limitations of the hardening soil model. It can be shown, that the approach of DIN 4085 for the coefficient of active and passive earth pressure and the mobilisation functions of Bartl, Besler and Vogt are good approximations. Particularly it could be verified that the coefficients of earth pressure proposed by Pregl [4] and Sokolowski [5] are a good approach for parallel wall movement and that the reduction factors for rotation about the top and rotation about the foot of the wall, proposed in DIN 4085, give realistic results. [ABSTRACT FROM AUTHOR]

Netzwerke von Sensoren für verschiedene Messgrößen stellen zunehmend das Rückgrat für eine Vielzahl von Anwendungsgebieten in beispielsweise Industrie, Maschinenbau und Umweltüberwachung dar. Dabei spielt das Zusammenführen der Daten (Sensorfusion) eine zentrale Rolle in der Anwendung und ist im Allgemeinen ein gut untersuchtes Forschungsgebiet. Die Berücksichtigung metrologischer Grundprinzipien wie Kalibrierung, Messunsicherheiten und damit Rückführung auf das SI-Einheitensystem für vergleichbare und reproduzierbare Messergebnisse ist jedoch vergleichsweise wenig untersucht. Dieser Beitrag diskutiert Grundsatzfragen, stellt Lösungsansätze aus dem aktuell laufenden EMPIR-Projekt "Metrology for the Factory of the Future" (Met4FoF) vor und gibt einen Ausblick auf zukünftige Forschungsfelder. Dabei fokussiert sich der Artikel auf das Anwendungsfeld der sog. „Industrie 4.0" als „Fabrik der Zukunft". Networks of sensors for different measured variables increasingly represent the backbone for a multitude of application areas, for example in industry, mechanical engineering and environmental monitoring. The merging of data (sensor fusion) plays a central role in the application and is generally a well investigated field of research. However, the consideration of metrological basic principles such as calibration, measurement uncertainties and thus traceability to the SI unit system for comparable and reproducible measurement results is comparatively little investigated. This article discusses fundamental questions, presents solutions from the current EMPIR project "Metrology for the Factory of the Future" (Met4FoF) and gives an overview of future research fields. The article focuses on the field of application of the so-called "Industry 4.0" as the "Factory of the Future". [ABSTRACT FROM AUTHOR]

Copyright of Technisches Messen is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Technisches Messen is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In modern tunnelling, deformation monitoring is an important component to ensure a safe construction. It is state of the art to measure displacements at the inner side of the tunnel lining using total stations. In addition, pointwise geotechnical sensors, e.g. electric strain gauges, may be installed in geological fault zones, which, however, do not deliver a complete picture of the internal deformations. The Institute of Engineering Geodesy and Measurement Systems (Graz University of Technology) supported by the Austrian Federal Railways (ÖBB‐Infrastruktur AG, SAE Fachbereich Bautechnik/Tunnelbau) developed a fibre optic sensing system, which realizes thousands of measurement points inside the tunnel lining. The distributed measurements can be used to assess the in‐situ strain behaviour as well as to localize failures (e.g. cracks) in the lining. This paper reports about the calibration of the fibre optic system under well‐known laboratory conditions and the practical utilization of the system in mechanized and conventional tunnelling. The results demonstrate the high potential of distributed fibre optic systems and their capability especially in the operational phase to extend classical measurement methods in tunnelling projects. [ABSTRACT FROM AUTHOR]

Das Eidgenössische Institut für Metrologie METAS verfügt über ein Kalibriersystem für Power Quality Analyser, das auf das Internationale Einheitensystem SI zurückgeführt ist. Es wird für die Kalibrierung, Prüfung und unabhängige Zertifizierung von Power Quality Analysern verwendet. In diesem Artikel wird zunächst das Themenfeld Versorgungsqualität betrachtet, wobei die normierten Kenngrößen kurz erklärt werden. Anschließend wird das Kalibriersystem des METAS erklärt und eine Messunsicherheitsberechnung am Beispiel der Kenngröße Flicker durchgeführt. The Federal Institute of Metrology metas in Switzerland operates a calibration system for power quality analysers. This system is traceable to the International System of Units si. It is used for calibration, testing and independent certification of power quality analysers. This article introduces the basic concepts of power quality and the standardised power quality parameters. The calibration system designed by metas is explained. As an example, the uncertainty budget for the parameter flicker is established. [ABSTRACT FROM AUTHOR]

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Copyright of Der Pathologe is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Automatisierungstechnik is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)