Title:
ガス分析方法
Document Type and Number:
Japanese Patent JP4187321
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To realize a method for calibrating a mass spectrometer without specially introducing a calibration gas by obtaining a calibration coefficient for the mass spectrometer from the ratio between the pressure value measured by a total pressure vacuum gage and the total ion current value measured by the mass spectrometer. SOLUTION: When newly setting a sample 11 in a baked vacuum tank 4, the vacuum tank 4 is exposed to the air and moisture in the air is adsorbed to the inner wall of the vacuum tank 4. When the vacuum tank 4 is evacuated by vacuum pumps 5, 6, the adsorbed water molecules is desorbed to become a principal component of a residual gas in the vacuum tank 4. At this time, the pressure in the vacuum tank 4 is measured by a total pressure vacuum gage 3 and an ion current value for each mass electric charge ratio m/e is measured by a mass spectrometer 3. The ratio P/IC (Total) of the measured total pressure P and total ion current value IC (Total) corresponds to a calibration coefficient of a conventional example. A considerably stable value of the ratio P/IC (Total) with a water molecule ration of, e.g. not smaller than 0.8 can be obtained, and is used as the calibration coefficient.
Inventors:
Kazuya Saito
Yukie Sato
Yukie Sato
Application Number:
JP28352398A
Publication Date:
November 26, 2008
Filing Date:
September 18, 1998
Export Citation:
Assignee:
ULVAC, Inc.
International Classes:
G01N27/62; H01J49/26; G01L21/30; G01N7/14
Domestic Patent References:
| JP9021784A | ||||
| JP8145835A | ||||
| JP4160357A |
Attorney, Agent or Firm:
Junichi Omori
Ori Akira
Yasuo Iisaka
Ori Akira
Yasuo Iisaka