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Gewählte Master / Diploma Thesis:

Karl Jochen Voltmer (2002): Durchfluss- und Temperaturmessungen in Kühllagerungen zur Ermittlung absorbierter Energie von Laserstrahlung.
Master / Diploma Thesis, BOKU-Universität für Bodenkultur. UB BOKU obvsg

Data Source: ZID Abstracts
The diploma thesis deals with the development and the description of the functionality of a methodology to determine the power of a laser beam by measuring the up-heating and the flow rate of a cooling liquid. The discrete signals of temperature and flow rate are transferred to an analog/digital converter and further to a signal processor. In cooperation with INCISION Lasertec GmbH a specific software package was developed ensuring a reliable evaluation procedure. The thermodynamical and mathematical derivations, the method is based on, are described in detail in the diploma thesis. The developed methodology allows the determination of the power of a laser beam by two distinguished methods, namely for short time and for long time measurements, respectively. The long time measurement aims at determining the power of a continuous beam and can also be used for monitoring and controlling the long term stability of the laser beam. In the short time mode the laser beam needs to be active only for a time period of 1 to 2 seconds. This allows the measurement of the laser power during the production process, i.e. in short production intervals such as, e.g., during the exchange of work pieces. By this way, in the case of an unacceptable deviation of the power from the scheduled value, corrections can be performed immediately by active control, and the whole production processes can be optimized. A further benefit of the developed measurement procedure in industrial production processes that the produced sensor signals and control impulses can be transferred to other computers or processors. The work described in the diploma theses demonstrates a successful realization of an indirect method for measuring the power of a laser beam by monitoring temperature changes and mass flow of a cooling liquid through a sensor.

Beurteilende(r): Loiskandl Willibald

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