| 摘要 |
PURPOSE:To detect deterioration of a seal effect of a magnetic fluid prior to leakage of gas by disposing a space for a gas reservoir in the middle of a magnetic fluid seal coupler in the longitudinal direction and providing the first and second magnetic fluid seal areas in such a manner as to sandwich the space therebetween. CONSTITUTION:A gas reservoir space 1 is disposed in the middle of a seal coupler in the longitudinal direction, and magnetic fluid seal areas 3, 6 are provided with the gas reservoir space 1 sandwiched therebetween. Even if the seal effect of a magnetic fluid in the first magnetic fluid seal area 3 is deteriorated by halogen gas, the seal effect of a magnetic fluid in the second magnetic fluid seal area 6 is not deteriorated quite, so that gas including halogen gas flowing out from a gas sealing device is collected in the gas reservoir space 1. Thus the deterioration of a seal effect of the magnetic fluid can be found from a pressure change in the gas reservoir space 1 or the existence/ absence of halogen gas. |
