Adjustment concept for compensating for stiffness and tilt sensitivity of a novel monolithic electromagnetic force compensation (EMFC) weighing cell. - In: Journal of sensors and sensor systems, ISSN 2194-878X, Bd. 11 (2022), 1, S. 109-116
This paper describes the new adjustment concept of novel planar, monolithic, high-precision electromagnetic force compensation weighing cells. The concept allows the stiffness and the tilt sensitivity of the compliant mechanisms that are dependent on the nominal load on the weighing pan to be adjusted to an optimum. The new mechanism is set up and adjusted according to the developed mechanical model. For evaluation of the concept the system is tested on a high-precision tilt table and under high vacuum conditions in the environment of a commercially available mass comparator.
https://doi.org/10.5194/jsss-11-109-2022
Sensor and Measurement Science International Conference 2021. - In: Technisches Messen, ISSN 2196-7113, Bd. 89 (2022), 1, S. 1-3
https://doi.org/10.1515/teme-2021-0116
Kraftmessung von Elektroden an einem menschlichen Kopfmodell :
Force measurement of electrodes on a human head model. - In: Technisches Messen, ISSN 2196-7113, Bd. 88 (2021), 11, S. 724-730
Electroencephalography (EEG) and transcranial electric stimulation (TES) require caps for holding the respective electrodes in place. To support the optimal design of such caps, knowledge of the force-displacement curves for each electrode position is desirable. We propose a calibrated setup to traceably measure force-displacement curves which consists of a human head model, a force sensor, a linear guide, a stepper motor, and a multiplexing multimeter. Repeated measures of a textile EEG-cap and a TES-cap show significant non-linearity and hysteresis effects for the force-displacement curves. Our setup will allow for the assessment of the fit of EEG and TES-caps for various head shapes and sizes.
https://doi.org/10.1515/teme-2021-0082
Fortschritte in der Entwicklung einer Planck-Waage (Planck-Balance 2 - PB2): eine Tabletop-Kibble-Waage zur Kalibrierung von Gewichten der Klasse E2 :
The progress in development of the Planck-Balance 2 (PB2): a tabletop Kibble balance for the mass calibration of E2 class weights. - In: Technisches Messen, ISSN 2196-7113, Bd. 88 (2021), 12, S. 731-756
In this paper we present the progress in development of a table-top version of the Kibble balance under the name Planck-Balance 2 (PB2). The PB2 is developed as a collaboration effort between the Technische Universität Ilmenau (TU Ilmenau) and Physikalisch-Technische Bundesanstalt (PTB) aiming for automatized mass calibration of the set of weights in the range from 1 mg to 100 g within the required uncertainties as stated by OIML recommendation R111 for weights of E2 class. We describe the design and the operational performance of the PB2 system in detail, the results of rigorous investigations of the error sources and subsequent improvements made since the beginning of the project in early 2017, the measurement data with the corresponding relative uncertainties and the preliminarily obtained uncertainty budget.
https://doi.org/10.1515/teme-2021-0101
Fibre-optical calibration of position sensors for Planck-Balances :
Faseroptische Kalibrierung von Positionssensoren für Planck-Waagen. - In: Technisches Messen, ISSN 2196-7113, Bd. 88 (2021), 12, S. 757-763
Zur Kibble-Kalibrierung von EMK-Systemen (sogenannte Planck-Waagen) muss die induzierte Spulenspannung, sowie die Geschwindigkeit der Aktorspule während der Bewegung relativ zum Magnetfeld erfasst werden. Die Bestimmung der Geschwindigkeit erfolgt anhand der, über die Zeit, gemessenen Position. Als Alternative zur interferometrischen Messung wird in diesem Artikel ein Verfahren zur faseroptischen Kalibrierung der, bei EMK-Systemen weit verbreiteten, optischen Positionssensoren vorgestellt. Der eigens entwickelte faseroptische Sensor, sowie die theoretisch beschriebene Kalibrierung wurden an einer Planck-Waage messtechnisch validiert. Im direkten Vergleich mit einem kommerziellen Interferometer wurden Kennlinienabweichungen von unter 60 nm über einem Bewegungsbereich von ± 12 [my]m erzielt.
https://doi.org/10.1515/teme-2021-0106
Quantum-based sensors for detection and discretization of currents in EMFC weighing systems :
Quantenbasierte Sensorik zur Erfassung und Diskretisierung von Strömen für EMK-Wägesysteme. - In: Technisches Messen, ISSN 2196-7113, Bd. 88 (2021), 12, S. 764-772
Hochpräzise Wägesysteme nach dem Prinzip der elektromagnetischen Kraftkompensation (EMK), wie Massekomparatoren, finden trotz Neudefinition der Einheit Kilogramm weiterhin Anwendung bei der Realisierung sowie Weitergabe einer praktischen Masseskale, indem sie metrologische Massevergleiche anhand des elektrischen Stromes als Zwischengröße ermöglichen. Gleichzeitig haben Quanteninterferometer auf Basis einer supraleitenden Hochgeschwindigkeitselektronik das Potential, kleinste Änderungen des magnetischen Flusses im Femtotesla-Bereich aufzulösen und eröffnen somit einen alternativen Ansatz zum Erfassen kleinster Stromdifferenzen. Die Kombination dieser bislang größtenteils nur für Fundamentalexperimente in der elektrischen Metrologie ausgenutzten quantenelektrischen Effekte mit Systemen der Präzisionskraftmessung ist eine neuartige Ausgangsbasis zur Verbesserung der Messgenauigkeit dieser Referenzsysteme. Insbesondere bietet die Anwendung eines quantenbasierten Analog-zu-Digital-Wandlers ein deutliches Potential zum Erschließen bisher unerreichter Genauigkeiten. In diesem Beitrag werden die Ergebnisse erster experimenteller Arbeiten zum Nachweis des grundlegenden Funktionsprinzips präsentiert. Darüber hinaus erfolgt eine Abschätzung der Leistungsfähigkeit sowie des Entwicklungspotentials des vorgestellten quantenbasierten Stromsensors für hochpräzise EMK-Wägesysteme.
https://doi.org/10.1515/teme-2021-0089
Naučnye issledovanija na osnove modelirovanija s celьju raspoznavanija sily putem monitoringa a deformacionnogo sostojanija gibkogo mechanizma :
Model-based investigations of force detection by monitoring the deformation state of a compliant mechanism. - In: Problems of mechanics, ISSN 1512-0740, (2021), No. 3(84), Seite 51-62
A strong, long-lasting pressure on the human skin whose effect is increased by shear forces can lead to the development of a pressure ulcer (decubitus). In order to minimize the risk of pressure ulcers developing, critical forces acting between the body and a sitting or lying surface should be detected and eliminated in time. One possibility for detecting critical forces is the actuation of tactile switches. In this article, miniature tactile switches are integrated into a compliant mechanism using the example of a MATF1 mattress spring made by Hartmann Kunststofftechnik GmbH & Co. KG. For this purpose, the deformation behavior of the spring is analyzed by means of non-linear analytical and finite elements method (FEM) calculations and the required tactile switches parameters as well as suitable locations for their placement are determined. A functional model is then built and examined.
Foreword to the special issue on "Tip- and laser-based 3D nanofabrication in extended macroscopic working areas". - In: Nanomanufacturing and metrology, ISSN 2520-8128, Bd. 4 (2021), 3, S. 131
https://doi.org/10.1007/s41871-021-00113-7
In-situ evaluation of the pitch of a reflective-type scale grating by using a mode-locked femtosecond laser. - In: Applied Sciences, ISSN 2076-3417, Bd. 11 (2021), 17, 8028, S. 1-16
Major modifications are made to the setup and signal processing of the method of in-situ measurement of the pitch of a diffraction grating based on the angles of diffraction of the diffracted optical frequency comb laser emanated from the grating. In the method, the improvement of the uncertainty of in-situ pitch measurement can be expected since every mode in the diffracted optical frequency comb laser can be utilized. Instead of employing a Fabry-Pérot etalon for the separation of the neighboring modes in the group of the diffracted laser beams, the weight-of-mass method is introduced in the method to detect the light wavelength in the Littrow configuration. An attempt is also made to reduce the influence of the non-uniform spectrum of the optical comb laser employed in the setup through normalization operation. In addition, an optical alignment technique with the employment of a retroreflector is introduced for the precise alignment of optical components in the setup. Furthermore, a mathematical model of the pitch measurement by the proposed method is established, and theoretical analysis on the uncertainty of pitch measurement is carried out based on the guide to the expression of uncertainty in measurement (GUM).
https://doi.org/10.3390/app11178028
Processing and analysis of long-range scans with an atomic force microscope (AFM) in combination with nanopositioning and nanomeasuring technology for defect detection and quality control. - In: Sensors, ISSN 1424-8220, Bd. 21 (2021), 17, 5862, insges. 17 S.
This paper deals with a planar nanopositioning and -measuring machine, the so-called nanofabrication machine (NFM-100), in combination with a mounted atomic force microscope (AFM). This planar machine has a circular moving range of 100 mm. Due to the possibility of detecting structures in the nanometre range with an atomic force microscope and the large range of motion of the NFM-100, structures can be analysed with high resolution and precision over large areas by combining the two systems, which was not possible before. On the basis of a grating sample, line scans over lengths in the millimetre range are demonstrated on the one hand; on the other hand, the accuracy as well as various evaluation methods are discussed and analysed.
https://doi.org/10.3390/s21175862