Abstract: The presence of trace molecules in air may be determined using an ion mobility spectrometer. Such devices may be used in the fields of explosives detection, identification of narcotics, and in applications characterized by the presence of very low airborne concentrations of organic molecules of special interest. The sensitivity of such instruments may depend upon on the method of gas sampling utilized. A virtual wall gas sampling system can greatly improve the sampling efficiency, particularly when the sampling needs to be performed at a distance from the air intake and large volumes need to be sampled. The virtual wall gas sampling system consists of an intake gas flow and a separate group of one or more sheet-like gas flows, which may be either mutually deflected to move with a circular motion or may be formed into a cylindrical bounding surface.

Abstract: The presence of trace molecules in air is often determined using a well-known device called an ion mobility spectrometer. Such devices are commonly utilized in the fields of explosives detection, identification of narcotics, and in applications characterized by the presence of very low airborne concentrations of organic molecules of special interest. The sensitivity of such instruments is dependent on the method of gas sampling utilized. The vortex sampling nozzle consists of an intake gas flow and a separate coaxial heated, emitted gas flow that is deflected to move with a circular motion. A heated vortex sampling nozzle can greatly improve the sampling efficiency for low volatility target molecules, particularly when the sampling needs to be performed at a distance from the air intake and the vapor pressure of the target molecules is very low.

Abstract: The presence of trace molecules in air is often determined using a well-known device called an ion mobility spectrometer. Such devices are commonly utilized in the fields of explosives detection, identification of narcotics, and in applications characterized by the presence of very low airborne concentrations of organic molecules of special interest. The sensitivity of such instruments is dependent on the method of gas sampling utilized. The vortex sampling nozzle consists of an intake gas flow and a separate coaxial heated, emitted gas flow that is deflected to move with a circular motion. A heated vortex sampling nozzle can greatly improve the sampling efficiency for low volatility target molecules, particularly when the sampling needs to be performed at a distance from the air intake and the vapor pressure of the target molecule is very low.

Abstract: The presence of trace molecules in air may be determined using an ion mobility spectrometer. Such devices may be used in the fields of explosives detection, identification of narcotics, and in applications characterized by the presence of very low airborne concentrations of organic molecules of special interest. The sensitivity of such instruments may depend upon on the method of gas sampling utilized. A virtual wall gas sampling system can greatly improve the sampling efficiency, particularly when the sampling needs to be performed at a distance from the air intake and large volumes need to be sampled. The virtual wall gas sampling system consists of an intake gas flow and a separate group of one or more sheet-like gas flows, which may be either mutually deflected to move with a circular motion or may be formed into a cylindrical bounding surface.