Title:
HOT-CATHODE IONIZATION GAUGE
Document Type and Number:
Japanese Patent JPS63198840
Kind Code:
A
Abstract:
PURPOSE:To improve a measurement limit by arranging an ion collector inside an anode approximately in a dot shape and also arranging a hot cathode outside the anode. CONSTITUTION:Two wire gauge materials are molded in a bowl shape of 24mm in diameter and brought into contact with each other to form the spherical anode 1. Part of the anode 1 below an annular collar 2 is swelled and a small hole 3 of 3mm in diameter is formed by abutting. The needlelike ion collector 4 and a pipe-shaped shield electrode 5 are arranged 1.5mm inside the anode 1 through the small hole 3. The diameter of the tip of the collector 4 is 0.03mm and the quantity of projection from the shield electrode 5 is 0.05mm, so the collector 4 is formed nearly in a dot shape. When an electron current flows between the hot cathode 8 which is supported by the support rod 9 and arranged outside the anode 1 and the anode 1, residual molecules in a vacuum strike on it and are ionized. The produced ions are caught by the collector 4 and the degree of the vacuum is measured. The collector 4 is in the dot shape, so the influence of a soft X ray emitted by the anode upon the photoelectron current is little. Then the measurement limit is improved to 10<-8>Pa.
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Inventors:
WATANABE FUMIO
Application Number:
JP3084587A
Publication Date:
August 17, 1988
Filing Date:
February 13, 1987
Export Citation:
Assignee:
WATANABE FUMIO
International Classes:
G01L21/32; (IPC1-7): G01L21/32
Domestic Patent References:
| JP42014992A | ||||
| JP45018828A | ||||
| JPS5589728A | 1980-07-07 | |||
| JPS5339173A | 1978-04-10 |
Attorney, Agent or Firm:
Yasuo Kato