Michael A Criddle

US Patent:

48474932, Jul 11, 1989

Filed:

Oct 9, 1987

Appl. No.:

7/107283

Inventors:

Ingvar E. Sodal - Boulder CO
Ronald R. Bowman - Boulder CO
Jerritt Hansell - Boulder CO
Justin S. Clark - Salt Lake City UT
Michael J. Criddle - West Valley UT

Assignee:

Masstron, Inc. - Boulder CO

International Classification:

B01D 5944
G01D 1800
H05H 302

US Classification:

2502521

Abstract:

Apparatus and method are provided for calibrating a mass spectrometer. The calibration hardware includes a relatively small, relatively low pressurized tank for containing calibration gas. The calibration gas tank is preferably located inside the same housing that contains the ion source assembly and the analyzing section of the mass spectrometer. Each of the calibration gas and sample gas, whose components are to be determined, communicates with its own associated valve. These two valves control the flow of a selected one of the sample gas and the calibration gas to the ion source assembly. The calibration gas valve has an extremely low leakage rate and can be controlled to permit the passage of very low flow rates of calibration gas, which can be of benefit in checking the linearity associated with the ion source assembly pressure. For each calibration procedure, very small amounts of calibration gas are utilized, in a range around 10. sup. -5 STD cc. A related method for conditioning an electron multiplier device is also disclosed in which the gain of one or more selected channels thereof is modified so that the output signal strengths of the device are comparable in magnitude.