Ion drift detector
US4831254A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 27, 1987 |
| Grant date | May 16, 1989 |
| Priority date | — |
| Expiry date | Jan 27, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J49/282
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An ion drift detector comprising an electrically insulating cylindrical tube. A means is provided for establishing along the tube a laminar flow of air into which heavier than air molecules, whose presence is to be detected, can be introduced. An ionizing means is disposed at a location on the central longitudinal axis of the tube for ionizing at least some of the molecules in the laminar flow. Disposed in the tube at a location downstream of the ionizing means there is provided a means for establishing a radial electric field extending across the space between the longitudinal axis and the wall of the tube, such that the ions formed on the axis of the tube are caused to be drifted generally radially across the laminar flow of air under the influence of the radial electric field. The tube also contains an ion collector arrangement which can detect the arrival of ions at different regions along the length of the tube, so that lighter and heavier ions can be distinguished by the extent of longitudinal travel along the cylindrical tube before the ions reach the wall of the tube.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.