Search results for "Temperature measurement"
showing 10 items of 123 documents
Riming of Graupel: Wind Tunnel Investigations of Collection Kernels and Growth Regimes
2009
Abstract Laboratory experiments were carried out in the vertical wind tunnel in Mainz, Germany, to study the collision coalescence growth of single spherical ice particles having initial radii between 290 and 380 μm while they were freely floated in a laminar flow containing a cloud of supercooled droplets with radii between 10 and 20 μm. The experiments were performed in a temperature range between −8 and −12°C, where riming proceeds in the atmosphere, and with cloud liquid water contents lying between 0.9 and 1.6 g m−3 (i.e., values typically found in mixed-phase clouds). The collection kernels were calculated from the mass increase of the rimed ice particles and the average liquid water …
A Measurement System for Power Inductors in Non-Linear Operating Conditions
2021
The exploitation of power inductors in switching converters outside the linear region requires detailed information on the magnetization curve that often is not included among those usually available on their datasheets. This paper proposes an automatic system in which the inductor is characterized in real operating conditions taking into account also the core temperature. It is based on a switching converter suitably controlled by a virtual instrument. The system was tested by retrieving the inductance vs current curves of two commercial inductors for core temperatures up to 105°C, showing the different behaviors of the magnetization curves. Results are coherent with data given by manufact…
European Dissemination of the Ultra-low Temperature Scale, PLTS-2000
2003
The first phase of the EU collaborative project on sub‐kelvin thermometry, ‘ULT Dissemination’, is nearing completion, leading to the development of several thermometers and devices, and the instrumentation needed to disseminate the new Provisional Low Temperature Scale, PLTS‐2000, to users. Principal among these are a current‐sensing noise thermometer (CSNT), a CMN thermometer adapted for industrial use, a Coulomb blockade thermometer, a second‐sound acoustic thermometer and a superconductive reference device SRD‐1000. Several partners have set up 3He melting‐pressure thermometers to realise the PLTS‐2000, and will check it using Pt‐NMR, CMN and other thermometers. The scale, which was for…
Wireless strain gauge network — Best-hall measurement case
2014
Wireless sensor networks can be used to perform structural monitoring. Strain gauges, which can be glued on or integrated to the observed material, are the most common nondestructive sensing elements for measuring surface strain. Wireless strain gauge measurement system makes strain measurements more flexible while opening new targets of application in addition to those that traditional wired strain measuring systems can offer. We have implemented a long term strain measurement in a PVC-covered hall using wireless sensor network. In this paper we evaluate the functionality and suitability of the developed wireless system for this kind of monitoring. The paper discusses the experiences gaine…
Analysis of thermally induced flows in the laboratory by geoelectrical 3-D tomography
2010
[1] Many natural bodies as well as materials inside industrial installations, such as the Earth's mantle and the glass inside melting furnaces, exchange matter through convection. These processes result from differences in temperature, density, and chemical concentration. In this analysis, we focus on the visualization of thermally driven flows in the laboratory. In nature and in industrial installations, it is difficult to measure the temperature inside the object of interest directly. We benchmark a new DC-geoelectrical 3-D tomography method for temperature measurements that allows obtaining temperature values without influencing the flow pattern. For verification of the method, we use di…
Predictive Power of the Emissivity Angular Variation of Soils in the Thermal Infrared (8–14 <inline-formula> <tex-math notation="LaTeX">$…
2018
A confident knowledge of land surface emissivity at viewing zenith angles far from nadir is of prime interest to perform an accurate correction of the anisotropy effect in the measurements made by orbiting thermal infrared (TIR) sensors. It is also important for the correct treatment of angular measurements carried out by remote sensors such as AATSR/ENVISAT, MODIS/Terra–Aqua, or the recently launched SLSTR/Sentinel-3, which can also be used for the angular normalization of land surface temperature due to viewing geometry effect. In this letter, the anisotropy of TIR emissivity predicted by two analytical, Warren–Wiscombe–Dozier and Hapke, models based on Mie diffraction theory was compared…
Numerical 2D modelling of turbulent melt flow in CZ system with dynamic magnetic fields
2004
Abstract The paper presents results of 2D axisymmetric mathematical modelling of laboratory CZ model facility that corresponds well to a large industrial silicon CZ growth system. The purpose of the investigation is to examine turbulent melt flow features that develop in the model crucible, when various dynamic magnetic fields (travelling, alternating) are applied, and to test the applicability of the modified low Re k–e turbulence model for the calculation of flows in these cases by extensive comparisons between calculated and measured data. The electromagnetic field is calculated with a self-developed program, and the calculations of the melt motion are carried out with the user modified …
Koblācija un radiofrekvences ķirurģija otolaringoloģijā. Literatūras apskats un salīdzinoši eksperimenti in vitro
2016
Radiofrekvences un radiofrekvences koblācijas metodes aizvien vairāk tiek pielietotas kā rīkles, tā deguna gliemežnīcu ķirurģijā, tomēr dati par šo procedūru laikā sasniegtajām temperatūrām audos ir skopi. Eksperimentālā pētījuma pirmajā daļā in vitro tika iegūti dati par sasniegtajām temperatūrām koblācijas laikā, kā arī veikta paraugu, ņemtu instrumenta pieskaršanās zonā, histoloģiskā analīze. Cūkas muskuļaudos tika sasniegta 370°C, kamēr submandibulārā dziedzera audos – 320°C temperatūra. Eksperimentālā pētījuma otrajā daļā cūkas deguna gliemežnīcās koblācija tika salīdzināta ar divām citām bipolārām radiofrekvences metodēm, tika iegūti dati par sasniegtajām temperatūrām šo metožu pielie…
Prediction of friction and heat flow in machining incorporating thermophysical properties of the coating–chip interface
2004
Abstract This paper deals with an experimental and analytical investigation into the thermodynamically activated effects influencing the behaviour of the multi-layered coated tool rake face during orthogonal cutting of ferromagnetic and paramagnetic steels. Temperature measurements on the tool rake face using a thermocouple-based technique and identification of the contact zone by means of computer image processing were carried out. New methodology for assessing friction and the amount of thermal energy generated when machining with a coated tool insert with natural and restricted contact coupled with a metallic chip, using thermophysical properties of the sliding materials is developed in …
Influence of the channel design on the heat and mass exchange of induction channel furnace
2011
PurposeThe purpose of this paper is to present in‐depth numerical modelling of heat and mass exchange in industrial induction channel furnace (ICF).Design/methodology/approachThe turbulent heat and mass exchange in the melt is calculated using a three‐dimensional (3D) electromagnetic model and a 3D transient large eddy simulation method. The simulation model has been verified by flow velocity and temperature measurements, which were carried out using an industrial sized channel inductor operating with Wood's metal as a low temperature model melt.FindingsThe ICF is well‐established for melting, holding and casting in the metallurgical industry. But there are still open questions regarding th…