| 摘要 |
PURPOSE:To provide an absolute reference surface of high reliability, by placing a float and a viscous fluid in a container on a base, providing a surface plate on the top of the float and using a balancing weight to determine the position of the float. CONSTITUTION:A container 8 is secured on a base 13. A float 7 and a viscous fluid 9 are provided in the container 8. The viscous fluid is enclosed by a seal 10. Stoppers 12 prevent the float 7 from being much displaced. A balancing weight 11 is provided in the internal opening of the float 7 to stabilize the position of the float. The float 7 can be turned within the allowable range determined by the stoppers 12, by changing the position of the balancing weight 11. The vibration of the floor is damped by the viscous fluid 9. |
