| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To monitor not only piston inclination but also eccentricity. <P>SOLUTION: A monitoring method for a piston of a dry type gas holder is provided with: a cylindrical holder body which extends in a vertical direction in order to store gas inside; a drop-lid-like piston which is disposed to be movable vertically within the holder body; and a seal mechanism for airtightly sealing a gap between a peripheral edge part of the piston and an inner circumferential surface of the holder body. In each of at least three positions on the piston in the equal distance from a center of the piston, there is provided an eccentricity measuring table with a predetermined size while being protruded by a predetermined height from an upper surface of the piston. In an upper end part of the holder body, there is provided a range finder for measuring a height direction distance to the eccentricity measuring table with no contact. When change occurs in the height direction distances measured by the range finder from the range finder to the eccentricity measuring tables in at least three positions: when the change is sharp, it is determined that eccentricity occurs in the piston; and when the change is smooth, it is determined that inclination occurs in the piston. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
