A novel contactless flow rate measurement device for weakly conducting fluids based on Lorentz force velocimetry. - In: Flow, turbulence and combustion, ISSN 1573-1987, Bd. 92 (2014), 1/2, S. 361-369
Richtiger Name des Verf.: Falko Hilbrunner
This paper presents an improved experimental setup for the contactless flow rate measurement in a weakly electrically conducting fluid on the base of Lorentz force velocimetry (LFV) and discusses the measurement results. The new setup embodies major improvements over the setup reported inWegfraß et al. (Appl Phys Lett 100:194103, 2012). This measurement setup consists of a newly designed fluid channel with well defined flow profiles - a plug profile at the inlet and quasi parabolic profile at the outlet of the test section. Another improvement is the force measurement system which is based on electromagnetic force compensation (EMC). Furthermore an optimized Halbach array is used as a magnet system. The results of our measurements confirm the feasibility of LFV in a model fluid (salt water) with conductivities less than 10 Sm-1 and demonstrate that the optimized magnet system increases the measurement signal. The used force measurement system had to be particularly calibrated for this purpose, so that in combination with the new magnet system design a three times higher signal resolution for the fluid velocity under laboratory conditions was achieved.
http://dx.doi.org/10.1007/s10494-013-9505-5
Contactless flow measurement of electrolytes using Lorentz force velocimetry :
Lorentzkraft - Anemometrie für die berührungslose Durchflussmessung von Elektrolyten. - In: Technisches Messen, ISSN 2196-7113, Bd. 79 (2012), 9, S. 399-402
http://dx.doi.org/10.1524/teme.2012.0263
Surface and coordinate measurements with nanomeasuring machines. - In: International journal of nanomanufacturing, ISSN 1746-9392, Bd. 8 (2012), 5/6, S. 467-483
The nanomeasuring machine (NMM-1) was designed for surface and coordinate measurements within a measurement volume of 25 mm × 25 mm × 5 mm. The machine is equipped with three homodyne plane-mirror miniature interferometers for the measurement of the displacement of a movable corner mirror. The object being measured is placed on the corner mirror, which is positioned by a three-axis drive system. Various measurement tasks are possible depending on the probe system installed. Most of the sensors utilised are one-dimensional tactile or optical surface sensors or probes. In recent years, measurements of three-dimensional features and sidewalls are becoming more important. For these more complex measurements, probe systems with two or three directions of sensitivity are necessary and were therefore integrated into the NMM-1. The article gives an overview of the operation and properties of the NMM-1, its use for surface and coordinate measurements, of integrated probe systems and of two probing systems developed.
Fixed point thermometers for thin pipelines :
Fixpunktthermometer für kleine Rohrquerschnitte. - In: Technisches Messen, ISSN 2196-7113, Bd. 79 (2012), 12, S. 559-562
Fixpunktthermometer wurden für den Einsatz in konventionellen Kraftwerken entwickelt und erfolgreich erprobt. Bei dezentraler Energieerzeugung sind zumeist kleinere Rohrdurchmesser (40 - 100 mm) für den jeweiligen Wärmeträgertransport üblich. Die Verwendung von Fixpunkt-Thermometern (mit Miniaturfixpunkttiegeln von mindestens 25 mm Länge) in solchen Rohrleitungen ist mit inakzeptabel großen Strömungsverlusten oder, bei zu geringer, Eintauchtiefe, mit einer Verfälschung der Thermoelement-Temperatur verbunden.
http://dx.doi.org/10.1524/teme.2012.0272
Thermoelemente für den Einsatz in Abgassystemen von Verbrennungsmotoren. - In: Technisches Messen, ISSN 2196-7113, Bd. 79 (2012), 10, S. 472-477
http://dx.doi.org/10.1524/teme.2012.0279
Flow rate measurement of weakly conducting fluids using Lorentz force velocimetry. - In: Measurement science and technology, ISSN 1361-6501, Bd. 23 (2012), 10, S. 105307, insges. 6 S.
http://dx.doi.org/10.1088/0957-0233/23/10/105307
Multi-sensor approach for multivalent applications in nanometrology. - In: International journal of automation and smart technology, ISSN 2223-9766, Bd. 2 (2012), 2, S. 141-145
The field of nanometrology is subject to increasing complexity as dimensional structures become more intricate with smaller structural widths and increasingly larger surface areas, and with the inclusion of thousands of inspection features. The relevant metrology tools thus need to provide the ability to measure in three dimensions with atomic resolution over large areas, and at a speed/throughput suitable for industrial applications. Ilmenau developed Nanopositioning and Nanomeasuring Technologies with an measuring range of tens of millimeter, subnanometer resolution and nanometer accuracy, allowing for combination with a multi-sensor approach for multivalent measurement and positioning applications in nanometrology.
http://dx.doi.org/10.5875/ausmt.v2i2.149
A multi-sensor approach for complex and large-area applications in micro and nanometrology. - In: Measure, ISSN 1931-5775, Bd. 7 (2012), 2, S. 44-50
In micro and nanotechnology, the metrological demands are increasing. The structures to be measured are becoming more complex with smaller structure widths, increasingly larger surface regions, and thousands of inspection features. In order to solve the problems, it has become desirable and even necessary to combine multi-sensor technology with high precision nanopositioning and nanomeasuring technology. The Nanopositioning and Nanomeasuring Machine NMM-1 with a measuring range of 25 mm x 25 mm x 5 mm and sub-nanometer resolution allows the application of several optical, tactile and atomic force probes. The combination of several sensor technologies in multi-sensor approach for application with the NMM-1 is demonstrated.
A universal noncontact flowmeter for liquids. - In: Applied physics letters, ISSN 1077-3118, Bd. 100 (2012), 19, S. 194103, insges. 4 S.
http://dx.doi.org/10.1063/1.4714899
Tactile 3D microprobe system with exchangeable styli. - In: Measurement science and technology, ISSN 1361-6501, Bd. 22 (2011), 9, S. 094018, insges. 7 S.
Over the past decade a trend of component miniaturization can be observed both in industry and in the laboratory, which involves an increasing demand for nanopositioning and nanomeasuring machines as well as for miniature tactile probes for measuring complex three-dimensional objects. The challenge is that these components - for example, diesel injectors, microgears and small optics - feature dimensions in the micrometre range with associated dimensional tolerances below 100 nm. For this reason, a significant number of research projects have dealt with microprobes for performing the dimensional measurements of microstructures with the goal of achieving measurement uncertainties in the nanometre range. This paper introduces an updated version of a 3D microprobe with an optical detection system developed at the Institute of Process Measurement and Sensor Technology. It consists of a measuring head and a separate probe system. The mechanical design of the probe system has been completely overhauled to enable the exchange of the stylus separately from the flexure elements. This is very important for the determination of the probing sphere's roundness deviations. The silicon membranes used in the first system design are therefore replaced by metal membranes. A new design of these membranes, optimized for isotropic probing forces and locking parasitic movements, is presented. Regarding the measuring head, the optical design has been redesigned to eliminate disruptive interference on the quadrant photodiode used for deflection measurement and to improve adjustment. Its dimensioning is discussed, especially the influence of the laser beam diameter on the interference contrast due to the parallel misalignment of the collimated laser beam. Initial measurement results are presented to prove functionality.
http://dx.doi.org/10.1088/0957-0233/22/9/094018