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181st Meeting of the Acoustical Society of America, ASA 2021

作者： Lamprecht, Raphael Scheible, Florian Semmler, Marion Sutor, Alexander Institute of Measurement and Sensor Technology UMIT - Private University for Health Sciences Medical Informatics and Technology Hall in Tirol Tirol6060 Austria Division of Phoniatrics and Pediatric Audiology Department of Otorhinolaryngology Head- and Neck Surgery FAU: Friedrich-Alexander-Universitat Erlangen-Nurnberg Bavaria Erlangen Germany

The material properties of the vocal folds play an important role in phonation, but are also of interest for basic research. In the diagnosis of e.g. vocal fold palsy ultrasound is still an emerging technology. Ultrasound elastography, a technique measuring the tissue stiffness, is widely employed in the diagnosis of e.g. liver fibrosis and thyroid nodules. Using a quasi-static approach, this technique can also be applied to the vocal folds, improving the understanding of their biomechanical properties and, in the future, the diagnosis of pathological changes in the vocal folds. We use a gelatin phantom of the vocal folds, modeled after the well-known M5 model of the true vocal folds and augmented with additional material that mimics the surrounding tissue. The phantom is compressed with an ultrasound transducer in the inferior direction, with the image plane in the frontal plane. Ultrasound images of the compression process and the acting force are recorded. Based on this information, a developed elastography algorithm evaluates the data. The results of the experimental setup are compared with simulation results generated using FEBio, a software specialized in tissue simulation. © 2022 Acoustical Society of America.

关键词： Phantoms

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Collinear Photothermal Gas Sensing with a Custom-Made Dichroic and Fiber-Coupled Fabry-Pérot Etalon

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IEEE sensors Journal 2025年

作者： Tanzer, Manuel Lang, Benjamin Bergmann, Alexander Graz University of Technology Institute of Electrical Measurement and Sensor Systems Inffeldgasse 33I Graz8010 Austria

Here, we present the implementation of a compact, collinear photothermal interferometry configuration for gas sensing based on a custom-made dichroic and fiber-coupled Fabry-Ṕerot etalon. By overcoming the design obstacles imposed by such a configuration, advantage of the strong signal enhancement due to the larger overlap of the pump and probe beam volumes was taken. A competitive NNEA of (Formula presented) and a limit of detection of 38.8 ppmv were achieved. Additionally, the more compact architecture of the sensing unit allows for further miniaturization of photothermal gas sensors. The proposed solution has been fabricated and tested, showing great promise for highly sensitive, selective and miniaturized gas sensors. © 2001-2012 IEEE.

关键词： Fabry-Perot interferometers

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Planar mapping of the liquid fraction of froth using ultrasound Flächige Darstellung des Wassergehaltes von Schaum mittels Ultraschall 21

Planar mapping of the liquid fraction of froth using ultraso...

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21. ITG/GMA-Fachtagung sensoren und Messsysteme - 21st ITG/GMA Conference on sensors and Measuring Systems

作者： Emmerich, Hannes Knüpfer, Leon Trtik, Pavel Eckert, Kerstin Heitkam, Sascha Starke, Eric Weik, David Büttner, Lars Czarske, Jürgen Technical University Dresden Laboratory of Measurement and Sensor System Techniques Dresden01069 Germany Helmholtz-Zentrum Dresden-Rossendorf Institute of Fluid Dynamics Dresden01328 Germany Paul Scherrer Institut Laboratory for Neutron Scattering and Imaging Villigen5232 Switzerland Technical University Dresden Institute of Process Engineering and Environmental Technology Dresden01069 Germany SICK Engineering GmbH Bergener Ring 27 Ottendorf-Okrilla01458 Germany

ISBN: (纸本)9783800758364

Flotation processes are essential processes for resource separation, the monitoring of which can save vast amounts of water and energy. To control them, it is necessary to measure the phase fractions present in the froth. Currently, no suitable measurement method exists that can be easily integrated into the existing process and has a penetration depth of more than 5 cm. Therefore, in this paper we present a measurement system for determining the liquid distribution in foam using ultrasound. To counteract the strong attenuating effect of the foam on the ultrasound, we use low-frequency probes with a center frequency of 135 kHz. Electrodes determine an integral liquid fraction by conductivity measurement. Within a liquid range of 0.17 ·10−2 to 0.82 ·10−2, the measurement system was first calibrated for a penetration depth of 9.2 cm and validated by simultaneous neutron imaging. An absolute and relative measurement uncertainty of 0.23 ·10−2 and 42.5 % was the respective result. A resolution of 7.5 mm in the axial, 13 mm in lateral direction and 1 Hz in time were obtained. In a dynamic inhomogeneous case, the measurement system was additionally validated for a use case. This investigation represents a first step towards process optimization in flotation processes. © VDE VERLAG GMBH ∙ Berlin ∙ Offenbach.

关键词： Ultrasonics

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Corner loading and its influence on the tilt sensitivity of precision weighing cells 20

Corner loading and its influence on the tilt sensitivity of ...

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20th International Conference of the European Society for Precision Engineering and Nanotechnology, EUSPEN 2020

作者： Darnieder, Maximilian Pabst, Markus Fröhlich, Thomas Theska, René Institute for Design and Precision Engineering Precision Engineering Group Technische Universität Ilmenau Department of Mechanical Engineering Institute for Process Measurement and Sensor Technology Process Measurement Technology Group Technische Universität Ilmenau Department of Mechanical Engineering

ISBN: (纸本)9780995775176

Corner loading and ground tilt are relevant error sources for precision weighing cells. The sensitive compliant mechanism of the weighing cell is subject to large dead weights with the aim to resolve small mass differences. Tilting of the base or an eccentric load application relative to the centre of the weighing pan result in lateral force components, apart from those in measurement direction. This changes the indication of the balance resulting in measurement errors. In this paper, a finite element model of the weighing cell was used to evaluate the corner load sensitivity in three directions and the tilt sensitivity in two directions. Based on a parametric study, an optimal attachment point for the weighing cell was found where all considered mechanical errors can be reduced to second order effects. Copyright © Proceedings of the 20th International Conference of the European Society for Precision Engineering and Nanotechnology, EUSPEN 2020. All rights reserved.

关键词： Cytology

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Mapping the optical dielectric response of isolated monolayer MoS2by push-broom microspectroscopy 2

Mapping the optical dielectric response of isolated monolaye...

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Unconventional Optical Imaging II 2020

作者： Dong, Xingchen Köhler, Michael H. Wang, Kun Jakobi, Martin Koch, Alexander W. Institute for Measurement Systems and Sensor Technology Department of Electrical and Computer Engineering Technical University of Munich Arcisstraße 21 Munich80333 Germany

ISBN: (数字)9781510634756

ISBN: (纸本)9781510634749

Two-dimensional van der Waals materials are attractive for photonics and optoelectronics due to distinctive layerdependent optical properties. Optical properties based on light-matter interactions have been revealed by modern imaging and spectroscopy techniques. Hyperspectral imaging microscopy working in line-scan mode (push-broom microspectroscopy) can provide abundant spectral information covering a large area compared to conventional spectroscopy techniques, with a higher acquisition speed than point-scan techniques such as atomic force microscopy and Raman imaging microscopy. This contribution studies in-depth the reconstruction of 3D datacubes and the extraction of optical responses of the sample. Monolayer MoS2, a subclass of semiconducting two-dimensional materials, is fabricated by the mechanical exfoliation method on the SiO2/Si substrate with an oxide thickness of 285 nm. The isolated monolayer MoS2 is observed and identified by a conventional optical microscope. The custom-built push-broom microspectroscope is utilized to scan the region of interest, with the whole spectrum of every line recorded at each frame. The spectral information of every point is collected and 3D spectral data sets are reconstructed for feature extraction and property analysis. To realize the thickness mapping of flakes, linear unmixing is employed to calculate the abundance of isolated monolayer MoS2 on the SiO2/Si substrate, improving flake identification performances. The characteristic spectrum of monolayer MoS2 is acquired by averaging the spectrum from the monolayer MoS2 flake. Furthermore, the optical dielectric response is further analyzed by Kramers-Kronig constrained analysis and Fresnel-law-based analysis. The optical dielectric function is calculated and compared based on the refractive index and medium thickness. This detailed analysis of optical dielectric responses highlights the feasibility of push-broom microspectroscopy for two-dimensional materials characterizat

关键词： Refractive index

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Linearity Characterization and Uncertainty Quantification of Spectroradiometers via Maximum Likelihood and the Non-parametric Bootstrap

arXiv

引用

arXiv 2022年

作者： Pintar, Adam L. Levine, Zachary H. Yoon, Howard W. Maxwell, Stephen E. Statistical Engineering Division National Institute of Standards and Technology GaithersburgMD20899-8980 United States Quantum Measurement Division National Institute of Standards and Technology GaithersburgMD20899-8441 United States Sensor Science Division National Institute of Standards and Technology GaithersburgMD20899-8441 United States

A technique for characterizing and correcting the linearity of radiometric instruments is known by the names the "flux-addition method" and the "combinatorial technique". In this paper, we develop a rigorous uncertainty quantification method for use with this technique and illustrate its use with both synthetic data and experimental data from a "beam conjoiner" instrument. We present a probabilistic model that relates the instrument readout to a set of unknown fluxes via a set of polynomial coefficients. Maximum likelihood estimates (MLEs) of the unknown fluxes and polynomial coefficients are recommended, while a non-parametric bootstrap algorithm enables uncertainty quantification (e.g., it can return standard errors). The synthetic data represent plausible outputs of a radiometric instrument and enable testing and validation of the method. The MLEs for these data are found to be approximately unbiased, and confidence intervals derived from the bootstrap replicates are found to be consistent with their target coverage of 95 %. For the polynomial coefficients, the relative bias was less than 1 % and the observed coverages range from 90 % to 97 %. The experimental data set is used to illustrate how a complete calibration with uncertainties can be achieved using the method plus one well-known flux level. The uncertainty contribution attributable to estimation of the instrument’s nonlinear response is less than 0.02 % over most of its range. Copyright © 2022, The Authors. All rights reserved.

关键词： Calibration

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A Double Node Thin-Film Thermocouples for In-Situ measurement

A Double Node Thin-Film Thermocouples for In-Situ Measuremen...

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Automation, Robotics and Computer Engineering (ICARCE), International Conference on

作者： Rong Ma Meiju Zhang Zhongkai Zhang Manguo Huang Xiaobo Liang Jiangjiang Liu Zhaojun Liu Bian Tian State Key Laboratory for Mechanical Manufacturing Systems Engineering Xi'an Jiaotong University Xi'an China Beijing Changcheng Aeronautic Measurement and Control Technology Research Institute Aviation Key Laboratory of Science and Technology on Special Condition Monitoring Sensor Technology Beijing China

ISBN: (纸本)9781665475495

The design, fabrication, testing and implementation of a new high-performance tungsten-rhenium thin film thermocouple are introduced. In this paper, tungsten-rhenium TFTCs are taken as the research object, after simulation analysis in COMSOL software and design, it is made by screen-printing technology and magnetron sputtering. This kind of thin film thermocouple primarily utilizes two kinds of electrode materials with varying composition combination, mainly tungsten with 5% rhenium and tungsten with 26% rhenium. Furthermore, high-temperature annealing is performed to maintain the mechanical properties and thus improve thermoelectric performance. The results demonstrate that the performance is reliable in the temperature range of 150-600 C° with a repeatability of 2.02%, providing application value for high-temperature in-situ sensing.

关键词： Temperature measurement Temperature distribution Thermocouples Tungsten Robot sensing systems Software sensors

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Fiber-optic multimode interference sensing: comprehensive characterization and its potential for strain-insensitive temperature sensing

arXiv

引用

arXiv 2022年

作者： Wang, Kun Mizuno, Yosuke Dong, Xingchen Kurz, Wolfgang Fink, Maximilian Lee, Heeyoung Jakobi, Martin Koch, Alexander W. Technical University of Munich Germany Department of Electrical and Computer Engineering Institute for Measurement Systems and Sensor Technology Munich80333 Germany Yokohama National University Faculty of Engineering Yokohama240-8501 Japan College of Engineering Shibaura Institute of Technology Tokyo135-8548 Japan

A strain-insensitive temperature sensor based on multimode interference using standard multimode fibers (MMFs) is proposed according to the comprehensive study of the characteristics of the MMFs. The temperature and strain dependences on the core diameter, numerical aperture (NA), and the length of the MMF section in the single-mode-multimode-single-mode (SMS) fiber structure are investigated experimentally. The results indicate that the larger core diameter of the MMF leads to higher temperature sensitivity but lower strain sensitivity (absolute values);the higher NA does not influence the temperature sensitivity but results in higher absolute value of strain sensitivity;the longer MMF section brings lower temperature sensitivity but does not have an impact on strain sensitivity. These findings also contribute to the theoretical analysis of the length dependence in the SMS fiber sensors. Besides, the results of the characterization study show that the strain sensitivity is relatively low, which brings a possibility to develop a strain-insensitive temperature sensor. The proposed sensor is used for temperature sensing while the strain is constantly applied from 0 to 1100 µΕ with steps of 100 µΕ. The measured results are consistent with the comprehensive study. The mean temperature sensitivity is 6.14 pm/◦C with a standard deviation of 0.39 pm/◦C, which proves that the proposed temperature sensor exhibits good stability and is insensitive to strain. We expect that these results will provide a profound guideline to fiber sensors based on multimode interference. Copyright © 2022, The Authors. All rights reserved.

关键词： Multimode fibers

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Hand-Guided Mobile Terahertz 3D Imaging Platform with Aspherical Telecentric f-? Optics 18

Hand-Guided Mobile Terahertz 3D Imaging Platform with Aspher...

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18th European Radar Conference, EuRAD 2021

作者： Mohammadzadeh, Shiva Keil, Andreas Leuchs, Sven Krebs, Christian Nubler, Dirk Seewig, Jorg Friederich, Fabian Fraunhofer Institute for Industrial Mathematics ITWM Materials Characterization and Testing Kaiserslautern Germany Becker Photonik GmbH Porta Westfalica Germany Fraunhofer Institute for High Frequency Physics and Radar Techniques FHR Wachtberg Germany Institute for Measurement and Sensor Technology TU Kaiserlautern Kaiserslautern Germany TU Kaiserslautern Department of Physics and Research Center OPTIMAS Kaiserslautern Germany

ISBN: (纸本)9782874870651

We present a hand-guided mobile terahertz imaging platform for non-destructive testing (NDT). The scanner acquires volumetric 3D image data using an integrated FMCW radar module in combination with a line scanning optics and a position encoder. Consisting of a galvanometer scanner mirror and an aspherical telecentric f-theta lens, the optical system enables B-scans perpendicular to the manual motion over a width of 2 cm. The guiding wheel system of the platform allows precise movement along cracks and welds, for example, enabling the volumetric inspection of the corresponding structures. The platform is optimized for working frequencies of up to 300 GHz. The frequency adaptability of the platform is demonstrated by measurements using a SiGe-chip-based 80 GHz FMCW radar module. © 2022 European Microwave Association (EuMA).

关键词： Frequency modulation

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Simulation and Verification of Pressure Drop in Silicon Microchannel Based on Porous Model Equivalence 21

Simulation and Verification of Pressure Drop in Silicon Micr...

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21st International Conference on Electronic Packaging technology, ICEPT 2020

作者： Chen, Chuan Ma, Rui Hou, Fengze Su, Meiying Li, Jun Cao, Liqiang Liang, Xiaobo Zhang, Meiju Liu, Ge Institute of Microelectronics of the Chinese Academy of Sciences Beijing China Aviation Key Laboratory of Science and Technology on Special Condition Monitoring Sensor Technology Beijing Changcheng Aeronautic Measurement and Control Technology Research Institute Beijing China

ISBN: (数字)9781728168265

ISBN: (纸本)9781728168265

Pressure drop is an important parameter of microchannel liquid cold plate. In this article, the pressure drop of the staggered strip fin microchannel was simulated based on porous model equivalence by FLUENT software. Periodic cell pressure drop was simulated to equal to that of the entire liquid cold plate. The parameters of the porous model were calculated by the relationship between pressure drop and flow rate. A model including manifold and liquid cold plate was established, in which the liquid cold plate was equivalent by the porous model, and the total pressure drop of the cooling module was acquired by simulation. Finally, a test system was built, and the simulation method based on the porous model equivalence was proved to be simple, efficient and accurate through the comparison of simulation and test values. © 2020 IEEE.

关键词： Pressure drop

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