Method and device for detection and identification of gases
First Claim
1. A device for identification of gases, comprising an inlet system and at least one detector, wherein at least one drift tube is delimited, on one hand, by the inlet system and, on the other hand, by the at least one detector, and that in each drift tube an opening and closing grid is disposed which divides an interior space of the drift tube into a reaction space and a drift space, wherein an ion source is arranged in the reaction space and a shield grid is arranged in the drift space, wherein the drift tube comprises several DC voltage electrodes, arranged around and along the reaction space and the drift space, that produce a constant electric field in the reaction space and the drift space, and AC voltage electrodes, wherein the AC voltage electrodes are distributed regionally along the length of the drift space, wherein the AC voltage electrodes of the drift tube comprise at least three AC voltage electrodes in the drift space, that produce an alternating asymmetric electric field in a region of the drift space operating along the same coordinate axis as the constant electric field, and the DC voltage electrodes and the AC voltage electrodes are arranged around the drift space, that each ionized molecule in the region of the drift space has a drift velocity caused by a resulting electric field, wherein the resulting electric field is the constant DC voltage field, on which the asymmetric AC voltage field is locally superimposed, wherein change in the drift velocity is due to each ionized molecule performing, due to the resulting electric field, a constant drift movement on which an oscillatory movement is superimposed, so that the ionized molecule performs a drift movement in one direction, that runs parallel to field lines of the resulting electric field, with the oscillatory movement superimposed collinear thereto.
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Accused Products
Abstract
Methods and devices identify gases and allow immediate and simultaneous detection of the chemical compounds to be tested. The methods and devices use a function of the electric field strength, for identification the material-specific mobility and simultaneously the change in this mobility, which is achieved in that due to the resulting electric field, each ionized molecule has a drift velocity which is partially increased or decreased, wherein the resulting electric field is a DC field, on which an asymmetric AC field is superimposed. The methods and devices for the detection and identification of gases are used to identify and detect chemical compounds, such as, explosive and/or unhealthy substances or compounds, which may be detected in very small concentrations.
26 Citations
18 Claims
- 1. A device for identification of gases, comprising an inlet system and at least one detector, wherein at least one drift tube is delimited, on one hand, by the inlet system and, on the other hand, by the at least one detector, and that in each drift tube an opening and closing grid is disposed which divides an interior space of the drift tube into a reaction space and a drift space, wherein an ion source is arranged in the reaction space and a shield grid is arranged in the drift space, wherein the drift tube comprises several DC voltage electrodes, arranged around and along the reaction space and the drift space, that produce a constant electric field in the reaction space and the drift space, and AC voltage electrodes, wherein the AC voltage electrodes are distributed regionally along the length of the drift space, wherein the AC voltage electrodes of the drift tube comprise at least three AC voltage electrodes in the drift space, that produce an alternating asymmetric electric field in a region of the drift space operating along the same coordinate axis as the constant electric field, and the DC voltage electrodes and the AC voltage electrodes are arranged around the drift space, that each ionized molecule in the region of the drift space has a drift velocity caused by a resulting electric field, wherein the resulting electric field is the constant DC voltage field, on which the asymmetric AC voltage field is locally superimposed, wherein change in the drift velocity is due to each ionized molecule performing, due to the resulting electric field, a constant drift movement on which an oscillatory movement is superimposed, so that the ionized molecule performs a drift movement in one direction, that runs parallel to field lines of the resulting electric field, with the oscillatory movement superimposed collinear thereto.
- 11. A method for identification of gases, wherein the gases to be identified are ionized and drift times of the ionized molecules through a drift space are measured and the measured drift times are evaluated by a gas identification device comprising at least one drift tube an inlet system and at least one detector, wherein the at least one drift tube is delimited, at a first end end, by the inlet system and, at a second end, by the at least one detector, wherein an opening and closing grid is disposed within the at least one drift tube and divides an interior of the drift tube into a reaction space and the drift space, wherein the drift tube comprises several DC voltage electrodes, arranged around and along the reaction space and drift space, that produce a constant electric field in the reaction space and drift space, and AC voltage electrodes, wherein the AC voltage electrodes are distributed regionally along the length of the drift space, that produce an alternating asymmetric electric field in a region of the drift space operating along the same coordinate axis as the constant electric field, wherein the DC voltage electrodes and the AC voltage electrodes are arranged around the drift space, wherein, for measurement of the drift times, the ionized molecules are firstly accelerated to a drift velocity in the drift space by the constant electric field and secondly ionized molecules that have the same drift velocity commonly enter the region in the drift space, wherein a resulting electric field formed by the constant electric field, on which the alternating asymmetric electric field is locally superimposed, additionally accelerates or decelerates the ionized molecules so that each ionized molecule has a drift velocity caused by the resulting electric field, wherein change in the drift velocity is due to each ionized molecule performing, due to the resulting electric field, a constant drift movement on which an oscillatory movement is superimposed, so that the ionized molecules perform a drift movement in one direction, that runs parallel to field lines of the resulting electric field, with the oscillatory movement superimposed collinear thereto.
Specification