Title:
【発明の名称】電離真空計
Document Type and Number:
Japanese Patent JP3069975
Kind Code:
B2
Abstract:
A vacuum ionization gauging tube, particularly a Bayard-Alpert (B-A) type vacuum ionization gauging tube, has a firmly compact construction, and provides the capabilities for minimizing outgassing gases and measuring pressures accurately without affecting the ultimate pressure range. The B-A vacuum ionization gauging tube includes a filament having a total surface area of between 6 mm2 and 20 mm2, a grid formed like a coil from a 0.1 mm to 0.3 mm diameter metal wire, the coil having a diameter of 5 mm to 7 mm and a length of 15 mm to 20 mm and across which it can be energized, an ion collector electrode having substantially the same length as the filament, and a metal envelope for enclosing the above electrode elements and which is maintained at a potential lower than that of the filament. The grid coil has a winding pitch of between 1.5 mm and 2.5 mm. The filament and grid are spaced apart from each other by the distance of between 2 mm and 4 mm. The metal envelope has an inner diameter of 20 mm to 30 mm, and the filament is located not more than 8 mm away from the inner wall of the metal envelope.
Inventors:
Shinji Osako
Toshio Kikuchi
Wakao Watanabe
Toshio Kikuchi
Wakao Watanabe
Application Number:
JP25455291A
Publication Date:
July 24, 2000
Filing Date:
September 06, 1991
Export Citation:
Assignee:
ANELVA Co., Ltd.
International Classes:
G01L21/30; G01L21/32; H01J41/14; (IPC1-7): G01L21/30; G01L21/32
Domestic Patent References:
| JP5628156U |
Attorney, Agent or Firm:
Masatsugu Suzuki