| 摘要 |
PURPOSE:To measure exactly and correctly expansion and contraction without putting a mark on a test piece by providing a light source for generating a parallel light, and an optical sensor for detecting a width divergent quantity of a reflected light from a test piece whose section is circular. CONSTITUTION:An extensometer has a light source 4 for generating a parallel light, and an optical sensor 8 for detecting a width divergent quantity of a reflected light from a test piece 2 whose section is circular. First of all, the test piece 2 is attached, for instance, to a tension tester. Subsequently, a parallel light is generated by the light source 4, and this parallel light is irradiated to the test piece 2 from its diameter direction (X direction). The parallel light irradiated to the test piece 2 generates a width divergence when it is reflected by the surface of the test piece 2, and its reflected light is photodetected by the optical sensor 8 bent by a half mirror 6. According to such a constitution, expansion and contraction of the test piece can be measured exactly and correctly without putting a mark on the test piece.
|
