A novel fiber-optic sensor used for small internal curved surface measurement

A novel fiber-optic sensor used for small internal curved surface measureme nt is presented. A measurement principle based on beam reflection is descri bed. Theoretically calculated curves and measured values are given. The res ults provide an essential theoretical and design basis for the measurement of curved surfaces with fiber-optic sensor. This sensor, which is composed of eight symmetrically cross-arranged receiving fibers and one centered emi tting fiber, can accomplish distance measurement with high vertical resolut ion of 0.1 mum through compensation of the impacts caused by fluctuations o f the surface reflectivity and light power. (C) 2000 Elsevier Science B.V. All rights reserved.