Abstract
This paper presented a simple laser measuring method for measuring small displacement of a thin plastic string. The laser measuring method is based on the deviation of laser energy method. This measuring system consists of a laser diode and a photodetector. A photodetector received the laser beam from the laser diode is used to detect the laser energy deviation. A straight thin plastic string is placed between the laser diode and the photodetector to cover half area of the photodetector. When the string moves into or out the photodetector, the amount of the laser energy will change proportionally to the displacement of the string. A plastic string for the tennis is tested in this paper. The relation between the displacement of a plastic string and deviation of laser energy is verified by using a linear moving stage and a laser interferometer. The result showed the correlation is obtained. Thus, the displacement of a plastic string can be measured using the proposed laser measuring system.
Publisher
Trans Tech Publications, Ltd.
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