| 摘要 |
PURPOSE:To enable the repair of a blocked first fine hole to be performed without breaking vacuum by installing a movable piece between the ionization part and the analyzing part of a mass spectrometer in which a two-stage differential exhaustion system is used so as to block a secondary fine hole. CONSTITUTION:In an atmosphere-ionization mass spectrometer, ions are introduced to an analyzer part 11 by two-stage differential exhaustion carried out by causing the ions to travel from an ionization part 2 having a corona-discharge electrode 1 through a first fine hole 7 before passing through an intermediate pressure part 8 having a second fine hole 7. Here, an O-ring gasket 13 is attached to a base plate 12 to which an electrode having the second fine hole 7 is fixed and the base plate 12 is pressed toward the O-ring 13 by means of a roller 10 having a spring 14 by moving a gate plate 9 up and down so as to maintain the vacuum of the analyzing part 11. As a result, when a disorder of the differential exhaustion part such as blocking of the first fine hole 3 occurs, cleaning can be performed without decreasing the vacuum degree of the analyzing part 11. Consequently, the rate of the operation of the mass spectrometer can be improved. |
