Fiber Optic Sensor System
Abstract
We describe the design, development, and performance of a microbend fiber optical domain reflectometry (OTDR) based distributed strains sensor. A test bed has been developed to evaluate and compare this system to conventional discrete strain gauge sensors. The test bed consists of an aluminum cantilever beam to which have been attached several pairs of strain gauges (for reference) and several microbend transducers. A single standard multi-mode optical fiber is threaded through the microbend transducers. The fiber is pulse illuminated by a commercial OTDR instrument. The microbend losses are detected as step changes in the return OTDR signal waveform. The transducers consist of small pairs of opposing sets of teeth, one set mounted on the flexible beam test bed, the other machined into a small, rigid cantilever bar mounted to produce scissor action as the beam flexes. The transducers are biased to produce a step loss with the beam in its neural position. The direction of beam deformation is then determined by the increase or decrease of the step size.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1989
- Accession Number
- ADA206636
Entities
People
- J. S. Schoenwald