| 摘要 |
<p>There is provided a length measuring machine which is not influenced by fluctuations of air or changes in temperature. At a structure, graduations are formed in a longitudinal direction, and further a built-in light wave interferometer is provided. The built-in light wave interferometer measures a length of the structure and supplies the data to a current controller. In order to reconcile a length of the structure with a nominal value, the current controller supplies current to an electrical resistor provided at the structure to cause thermal expansion of the structure, or the structure is cooled.</p> |
