Inlet system for an ion mobility spectrometer introduces poorly volatile samples into measuring cell with consistent results

摘要

An inlet system for an ion mobility spectrometer has a closed-circuit gas circulation system with drift cell, circulation pump, filter and branch tubes to the cell and sample inlet. The branch point (7) has a 3/2 way magnetic valve (8) by means of which in one selected position the gas feed is either through a by-pass tube (12), or via a second 3/2 magnetic valve (9) to the measuring cell gas inlet (4). In a second selected position of the magnetic valve (8) and gas path (9), the flow is to the gas outlet (10) and links a quasi-stationary sample source (11) with the measuring cell gas inlet (4).