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US 4,063,156 AGranted
Assymetric cylinder electron capture detector
AssigneeVarian Associates, Inc.
InventorPaul Louis Patterson
Life of this patent
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AssigneeVarian Associates, Inc.
InventorPaul Louis Patterson
Estimating the term…
An asymmetric cylinder electron capture detector comprises an electrode configured to define an ionization volume, a source of ionizing radiation disposed within the ionization volume, a collector electrode, with a gas flowing past the collector electrode into the ionization volume. The electron current to the collector electrode provides an indication of the presence of electronegative constituents in the gas passing into the ionization volume. In order to provide wide dynamic range, the face of the collector electrode is disposed as close as possible to the electrode defining the ionization volume, yet is located so as to minimize field-free background current. The collector electrode and the electrode defining the ionization volume are each of cylindrical configuration, and are coaxially aligned but are spaced apart with respect to each other. The two electrodes are mechanically connected via an intermediately disposed cylindrical insulator cylinder. The collector electrode is received in one end of the insulator cylinder, and the electrode defining the ionization volume is received within the other end of the insulator cylinder. The collector electrode has an elongate portion extending into the interior of the insulator cylinder, but spaced apart from the inner surface of the insulator cylinder. This configuration provides a long insulative path to prevent electrical leakage between the electrodes. A transverse gas exit port is provided in that portion of the collector electrode within the insulator cylinder in order to impart turbulence to the flow of gas through the insulator cylinder into the ionization volume.
An electron capture detector comprising a first electrode defining an ionization volume, a collector electrode disposed externally of said ionization volume, means for allowing a gas to flow past said collector electrode into said ionization volume, means for ionizing the gas in said ionization volume, and electrical pulse generating means connected to said electrodes for causing free electrons in said ionization volume to migrate to said collector electrode during a pulse, said electrodes being coaxially disposed with respect to each other, one end of said collector electrode being spaced apart from one end of said first electrode by no more than 0.125 inch.
An electron capture detector comprising a first electrode defining an ionization volume, a collector electrode disposed externally of said ionization volume, means for allowing a gas to flow past said collector electrode into said ionization volume, means for ionizing said gas within said ionization volume, and means connected to said electrodes for generating a sequence of electrical pulses for causing free electrons in said ionization volume to migrate to said collector electrode, said electrodes being spaced apart from each other by a distance no greater than that distance which will permit all free electrons in said ionization volume to migrate to said collector electrode during a single pulse of one microsecond duration.
An electron capture detector comprising a first electrode defining an ionization volume, a collector electrode disposed externally of said ionization volume, one end of said first electrode defining a plane and one end of said collector electrode being coplanar with said one end of said first electrode, means for allowing a gas to flow past said collector electrode into said ionization volume, means for ionizing said gas within said ionization volume, and means connected to said electrodes for generating a sequence of electrical pulses for causing free electrons in said ionization volume to migrate to said collector electrode, said electrodes being spaced apart from each other by a distance no greater than that distance which will permit all free electrons in said ionization volume to migrate to said collector electrode during a single pulse.
An electron capture detector comprising a first electrode defining an ionization volume, a collector electrode disposed externally of said ionization volume, said electrodes being of cylindrical configuration and being electrically isolated from each other by a generally cylindrical insulator structure, means for allowing a gas to flow past said collector electrode into said ionization volume, means for ionizing said gas within said ionization volume, and means connected to said electrodes for generating a sequence of electrical pulses for causing free electrons in said ionization volume to migrate to said collector electrode, said electrodes being spaced apart from each other by a distance no greater than that distance which will permit all free electrons in said ionization volume to migrate to said collector electrode during a single pulse.
An asymmetric cylinder electron capture detector comprising a generally cylindrical collector electrode, a generally cylindrical structure housing a source of ionizing radiation, and a generally cylindrical electrical insulator disposed intermediate said collector electrode and said radiation source housing structure;
A method for analyzing effluent gas from a chromatographic column by means of an electron capture detector having a collector electrode, a structure housing a source of ionizing radiation, and an electrical insulator disposed between said collector electrode and said radiation source housing structure, said collector electrode, insulator and radiation source housing structure being of generally cylindrical configuration and being coaxially aligned with but longitudinally separated from one another, said method comprising the steps of:
Dependencies are inferred from the claim text.