A simple optical extensometer achieving high accuracy
Abstract
A small, Fabry-Perot interferometer which may be mounted on a polymer test-piece for the measurement of changes in a dimension of the sample is described. The design maintains the wedge angle between the interferometer mirrors constant during dimensional changes, so the change can be related to the shift in fringe order at any point in the interference pattern. It was used to measure the lateral contraction of a test piece subjected to a uniaxial force, and results compare favorably with data obtained using an inductive displacement transducer. Accuracy of 0.01 microns is possible, even over a long period.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- January 1985
- Bibcode:
- 1985STIN...8531474D
- Keywords:
-
- Dimensional Measurement;
- Extensometers;
- Fabry-Perot Interferometers;
- Optical Measuring Instruments;
- Axial Loads;
- Contraction;
- Creep Tests;
- Displacement;
- Performance Tests;
- Instrumentation and Photography