| 摘要 |
PURPOSE:To measure thermal expansion coefficient with high accuracy, by placing a specimen in a core tube and measuring the thermal expansion coefficient of a specimen by a displacement measuring camera equipped with a telephoto lens and an infrared ray removal filter. CONSTITUTION:A core tube 24 is provided in a heating furnace 1 and quartz glass windows 27 are provided to both end parts of said core tube 24. A specimen 2 is placed in the core tube 24 and illuminated by an illumination apparatus 9, and the dark part blocked from light by the specimen 2 and a bright part where light directly reaches are received by a solid scanning light receiving element and displacement is detected from the ratio of the dark part and the bright part. For example, the light received from the specimen 2 is passed through an infrared ray removal filter 13 and enlarged by a telephoto lens 14 to be measured by the displacement measuring camera 15 of a photomultiplier tube. An exhaust port 28 and a gas introducing pipe 29 are provided to the core tube 24 to form an atmosphere different from that of the heating furnace 1. The temp. of the specimen 2 is measured by a thermocouple 12. Because the apparatus is constituted of the telescope lens, the infrared ray removal filter and the displacement measuring camera, the thermal expansion coefficient of a small specimen can be measured in an arbitrary atmosphere with high accuracy. |
