To maintain a minute positive pressure by suppressing pressure variation at the time of exchanging air between two closed modules in a closed system experiment equipment for executing plant cultivation or animal breeding. 植物栽培や動物飼育を行なう閉鎖系実験設備の閉鎖モジュール間で、空気交換時の圧力変動を抑制して微小正圧を維持する。 - 特許庁