Positioning an interferometric sensor with respect to the specimen requires a precise and expensive motion system to retain the sensors accuracy. A cost-efficient and precise setup requires a compensation of any run-out that the motion system induces. This contribution demonstrates that run-outs of a rotational axis can be compensated by implementing a low-cost interferometric point sensor to a previously presented interferometric line-scan system. Furthermore, the setup is extended by an evaluating algorithm that is capable of evaluating the line-sensor’s measurement data in real-time, using either a CPU or a GPU. An improved mechanical design of the interferometric sensor is introduced. It consists of fewer mechanical parts compared to previous versions, thus making the sensor more efficient in production and more robust against vibrations. An up-to-date high-speed line camera with a length of 4,000 pixels and line rate of up to 200 kHz increases the measurement rate of the sensor to up to 2,000 height values per second per camera pixel, enabling the sensor to evaluate 8 million height values per second.

Date Published: 21 June 2019
PDF: 7 pages
Proc. SPIE 11056, Optical Measurement Systems for Industrial Inspection XI, 110562D (21 June 2019); doi: 10.1117/12.2526033

Published in SPIE Proceedings Vol. 11056:
Optical Measurement Systems for Industrial Inspection XI
Peter Lehmann; Wolfgang Osten; Armando Albertazzi Gonçalves Jr., Editor(s)