Method for contactless measurement of surface speed of moved materials, involves assessing signal with two different functions that temporally vary synchronous to excitation function, and processing intermediate results for measuring speed

摘要

The method involves exciting coherent measuring beams in a measuring volume by an actuator. The excitation of the beams is performed in its relative optical path length or in modulation of a beam position on moved materials. Detected measurement values are separately processed synchronous to the excitation in periods of frequency-increase and -decrease during signal evaluation. A detector signal is assessed with two different functions that temporally vary synchronous to an excitation function. Intermediate results are processed for measurement of surface speed of moved materials.