C6.3 - Compact Optical Sensor for the Measurement of Surface Microtopographies on Turbine Blades

Event
AMA Conferences 2015
2015-05-19 - 2015-05-21
Nürnberg, Germany
Band
Proceedings SENSOR 2015
Chapter
C6 - Geometrial Measurements
Author(s)
Y. Li, M. Kästner, E. Reithmeier - Gottfried Wilhelm Leibniz Universität Hannover (Germany)
Pages
453 - 457
DOI
10.5162/sensor2015/C6.3
ISBN
978-3-9813484-8-4
Price
free

Abstract

The importance of measuring surface microtopographies for quality control has increased in the last decades. The inspection and measurement of complex shaped work pieces, like turbine blades or blisks (blade integrated disks), leads to a new challenge in measurement technology. In order to allow a precise measurement of surface microstructures, optical microscopes, such as confocal laser scanning microscopes and optical scanning microscopic interferometers, are usually used [1-3]. However, with common optical microscopes with 20x or 50x magnification objectives it is difficult to obtain a large spatial range which is necessary for measuring curved surfaces of turbine blades.
In this paper we present a compact non-contact measurement system based on a low coherence Michelson interferometer (LCI), which allows a nanometer-level vertical resolution and a millimeterlevel lateral range. The developed LCI-system using a telecentric lens allows a high accuracy surface microtopography measurement and a large FOV for measuring curved surfaces, which cannot be measured by common interferometric microscopes.

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