Method and apparatus for the detection and identification of trace gases

The present invention relates to an ion mobility spectrometer sensor apparatus which is in a hermetically sealed housing, utilizing a drift gas for the determination of trace contaminants in a carrier gas, including a container for a sample gas containing an analyte the concentration of which is to be determined, means for purifying the sample gas to produce the carrier gas from it, the means for purifying being hermetically connected from the container through a metallic pipe, a source for the purified drift gas which may be the same or different than the carrier gas, an ion mobility spectrometer sensor having a carrier gas entrance and a drift gas entrance and a gas exit, the ion mobility spectrometer sensor being hermetically connected by a metallic pipe from the purifying means and from the source of the drift gas, a back diffusion trap is hermetically connected from the gas exit, and a signal readout is electrically and hermetically connected from the ion mobility spectrometer sensor for electrically sensing and displaying signals obtained in the sensor.