摘要 |
A method and an apparatus for determining the location of a piece of timber having a flat top surface and two unfinished side surfaces or determining the width and location of its flat top surface is described. The piece of timber is subjected to radiation in such a manner that the top surfaces and the side surfaces are simultaneously subjected to radiation of different wave length. Light may be used as the source of radiation and rays of different wave length are reflected from the piece of timber and are separately detected by means of a light sensitive element.
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