Extensometer, Fiber Optic, Displacement
Tuesday, September 05, 2006
A Fiber Optic Extensometer has been designed and developed that senses surface displacement at two different locations simultaneously. The two locations are fixed relative to the Extensometer and the separation is the gauge length of the Extensometer. Strain level is obtained by measuring the differential displacement at the two measurement locations. Rigid body motion is measured at both locations and is canceled out. Each of the displacement measuring sensors is a pair of photodetectors that generate independent signals. This signal characterizes the displacement of the test sample at the measurement location.
The light scattered from the test sample surface is focused into a Fiber Optic connected to the Extensometer signal processing unit. The photodetectors are located inside the processing unit to provide shielding from electrical noise. A measurement of test sample surface displacement is made for both locations and the differential displacement is determined. Displacement is measured at each point by focusing two laser light beams on a test sample surface at a fixed angle. The displacement measurement is insensitive to any gradual changes in the reflectivity of the test sample surface.
Source: Optra, Inc., Beverly, MA
Reference: None Available
Industrial Products
posted by JD52 @ 10:05 PM,
