公开(公告)号：GB2391693B

公开(公告)日：2006-07-12

申请号：GB0209738

申请日：2002-04-29

Applicant: SS SCIENT LTD

Inventor： SHANNON STEVE

IPC: H01J41/10

公开(公告)号：GB2391693A

公开(公告)日：2004-02-11

申请号：GB0209738

申请日：2002-04-29

Applicant: SS SCIENT LTD

Inventor： SHANNON STEVE

IPC: H01J41/10

Abstract: A miniaturised vacuum gauge has an ion source, mass filter, and miniaturised electronics. The mass filter has four electrodes E'1 - E'4 each having a working surface of hyperbolic section with the four working surfaces disposed symmetrically about a longitudinal axis of the filter so that the working surfaces in combination define a star shaped volume the centre of the working surface serving to define a point on a constant inscribed circle about, and extending along, the longitudinal axis.