Process for producing standard gas mixture and apparatus for producing the same.

摘要

The present invention relates to a process and an apparatus for producing standard gas mixtures for testing, calibrating, ... highly sensitive analytical instruments such as an atmospheric-pressure ionization mass spectrometer (APIMS). According to the invention, the following functions can be carried out : Introduce the gas to be analyzed in a controlled way into the analyzing device ; add to the gas to be analyzed, calibrated amounts of gaseous species in order to apply the standard addition and internal standard generation methods ; introduce a blanc or zero gas into the analyzing device ; add to the zero gas calibrated amounts of gaseous species in order to generate controlled mixtures facilititating the calibration of the analyzing device ; dilute in a controlled way the gas to be analyzed by the zero gas before introduction of the mixture into the analyzing device. This last point is particularly relevant for very polluted, or toxic and/or corrosive gases. The above functions are completed without the addition of contaminants,which is specially important when doing ultratrace level analysis.