Process for producing low-concentration gas mixtures, and apparatus for producing the same

US5054309A · kind A · utility

Assignee

• L'Air Liquide, Societe Anonyme Pour l'Etude et l'Exploitation des Procedes Georges Claude · FR

Inventors

• Jacques Mettes · Ivyland, US
• Takako Kimura · Urayasu, JP
• Michael Schack · Düsseldorf, DE

Key dates

• Filing date: Nov 17, 1989
• Grant date: Oct 8, 1991
• Expiry date: Nov 17, 2009

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T137/0352
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

This invention relates to a process for producing gas mixtures by a plurality of dilution steps of a high concentration standard gas with a high purity diluent gas. According to the invention, as soon as the high purity diluent gas is generated, no further contaminants such as gaseous impurities are added during the further mixing of diluting steps of the process. Only orifices or needle valves are used in the mixing or diluting lines while mass flow controllers and pressure regulators are placed upstream, at the output of the gas sources and/or downstream, i.e. in the gas-venting lines. The invention particularly applies to trace analysis of gas with Atmospheric Pressure Ionization Mass Spectrometry.