An ultra-sensitive optical detector with large time resolution, using a surface plasmon. The rights allocation system confers, on a sub-program shared by at least two programs, temporary rights of access to certain memory zones. On boot-up, the current boot record is compared with its corresponding snapshot. According to such structure, the fluid traveling through said bellows-type outer cylinder 31 and the impurities contained in the fluid are prevented from residing in the grooves formed to the inner circumferential surface of the bellows-type outer cylinder 31, and the cleanness and quality maintaining property of the expansion joint device is secured.