Apparatus to detect substances of interest in an air flow, e.g. drugs of abuse, has an ion mobility detector at the inflow operated alternately by high and low drift voltages to give a high resolution

摘要

The apparatus to detect a substance of interest in air has an inflow for the air sample with an ion mobility detector (1), operated by alternating high and low drift voltage levels to determine if such a substance is present. At least one high tension supply (4) provides the power for the detector. A control unit (8) is connected to the detector and the power supply, to give a selective drift voltage reduction. A reaction chamber (5) is linked to the inflow, to ionize molecules, with a drift tube containing a collector electrode (7). An electrode (2) gives a defined field between the reaction chamber and the collector electrode.