Proportional counter device for detecting electronegative species in an air sample
AssigneeMartin Marietta Energy Systems, Inc.
InventorsSteve L. Allman, Fang C. Chen, Chung-Hsuan Chen
Life of this patent
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Abstract
Apparatus for detecting an electronegative species comprises an analysis chamber, an inlet communicating with the analysis chamber for admitting a sample containing the electronegative species and an ionizable component, a radioactive source within the analysis chamber for emitting radioactive energy for ionizing a component of the sample, a proportional electron detector within the analysis chamber for detecting electrons emitted from the ionized component, and a circuit for measuring the electrons and determining the presence of the electronegative species by detecting a reduction in the number of available electrons due to capture of electrons by the electronegative species.
Claims26
Apparatus for detecting the presence of an electronegative species in an air sample comprising:
- a proportional counter comprising an analysis chamber, an electrode extending through said analysis chamber and electrically insulated therefrom, and charging means in electrical communication with said electrode for charging said electrode to a positively charged state relative to said analysis chamber, said positively charged state being sufficient to attract toward said electrode electrons produced by ionization of at least a portion of an air sample to produce gas amplification therein;
- an air sampling means in fluid communication with said analysis chamber for admitting an air sample into said analysis chamber;
- an ionization means disposed within said analysis chamber for ionizing at least a portion of the air sample;
- and,
- a circuit means in electrical communication with said electrode for measuring the quantity of electrons collected at said electrode for determining the presence of an electronegative species in the air sample by detecting a reduction in the number of electrons collected at said electrode, said reduction due to capture of electrons by the electronegative species.
A method for detecting the presence of an electronegative species in an air sample comprising the steps of:
- providing a proportional counter comprising an analysis chamber, an electrode extending through said analysis chamber and insulated therefrom;
- charging said electrode to a positively charged state relative to said analysis chamber, said positively charged state being sufficient to attract toward said electrode electrons produced by ionization of at least a portion of an air sample to produce gas amplification therein;
- admitting an air sample into said analysis chamber;
- ionizing at least a portion of said air sample to produce electrons which are attracted toward said electrode to produce gas amplification;
- and,
- measuring the quantity of electrons collected at said electrode to determine the presence of said electronegative species in said air sample by detecting a reduction in the number of electrons collected at said electrode, said reduction due to capture of electrons by said electronegative species.
Dependencies are inferred from the claim text.