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| Abstract No.: |
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Scheduled at:
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Monday, May 03, 2010, Hullet Room 2:00 PM
Process Diagnostics 1
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| Title: |
NIR (Near-Infra-Red) sensor ? an alternative diagnostic tool for the online process control of thermal spray processes
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| Authors: |
Alexander Schwenk* / GTV Verschleiss-Schutz GmbH, Germany
Swen Marke / IFU Diagnostics Systems GmbH, Germany
Till Wallendorf/ IFU Diagnostics Systems GmbH, Germany
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| Abstract: |
After the today?s state of the art ?insitu - real time control systems? are absolutely necessarily in modern turn key applications within the field of the thermal spray technology in regard to the quality and reproducibility of thermal spray coatings for a large range of industrial applications. Compared with the already existing diagnostic systems and their algorithms which are developed on the basis of CCD-cameras, an algorithm can be developed for insitu - real time control systems which possesses a by far closer physical purchase for the determination of the particle characteristics due to their measurement setup. Thus approx. 200 particles per millisecond can be detected as well as average particle velocities within the range 100 - 1000 m/s and average particle surface temperatures in between 750 and 2000 °C can be deter-mined. A statistical distribution of approx. 3000 particles is considered for the com-putation of the on-line measured average particle velocities and -surface tempera-tures. Thus the determined average particle characteristics are subject to clearly lower fluctuations during the measurements than the average particle characteristics measured in the same process by using a diagnostic system based on a CCD camera. Furthermore, for the measurements with the NIR-sensor substantially less mathe-matical adjustments in the algorithm are needed for the determination of the aver-age particle characteristics and the measuring error range of tolerance is clearly smaller compared with the camera measuring systems, which can indicate an error range of tolerance up to 10%. The accuracy of the measurement determines the use of an on-line process control during thermal spraying processes.
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