Ruehl, F.F.RuehlNoll, ReinhardReinhardNoll2022-03-082022-03-081993https://publica.fraunhofer.de/handle/publica/302893Device for the contact-less measurement of object oscillations comprising a laser beam (16), which is trained at different measuring points (17) in turn on the measured object (18) by means of a beam deflection device (7) determining the single-beam direction of formula I, consisting of a sensing head (12) sensing the stray light of a laser beam (16) resulting from the measured object (18), said sensing head (12) being connected to a receiver (24) comprising a frequency-shifted laser beam (6) which is superimposed on the stray light of the measured object (18) in the receiver (24), and an evaluation device (15) connected to the receiver (24). In order to be able to measure the measuring points(17) of a measured object (18) for their movements occurring in three spatial directions, the device is designed so that, at one measuring point (17), a total of three sensing heads (12, 13, 14) outside the single-beam direction of formula 2 of the laser beam (16) receiving the stray light of the laser beam (16) resulting from the measured object (18) are fixed in a plane not indicating the measuring point (17) for the purpose of measuring the movements of the measured object (18) occurring in three spatial directions (x, y, z), said sensing heads being connected to the receiver, and so that a position-locating device (14') is provided for determining the relative position of the measuring point (17) on the laser beam (16).de608621patent1991-4106572