Continuous air monitoring system
AssigneeGemini Research, Inc.
InventorsRichard W. Tucker, John E. McGreevy
Life of this patent
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Abstract
A continuous air monitor is provided with the capabilities of monitoring certain transuranic and other airborne radioactive particulate with high accuracy and low false alarm rates in the presence of radon and thoron daughter products. A multiple filter sampling approach is used wherein air flow is directed on a alternating basis to each sampling filter in turn. Each filter collects particulate in the size range of interest. Beta and/or alpha activity can be continuously measured on each filter. The air flow can be directed through a chamber where radon and/or thoron gas portions of the air may decay into their daughters and the quantities thereof may be separately measured.
Claims13
A continuous air monitoring system comprising:
- an air intake port;
- at least two air filtering means in fluid communication with the air intake port;
- selection means for selectively supplying air from the air intake port to a predetermined one or more of the filtering means;
- detection means positioned relative to the filtering means for measuring the level of radioactivity of particles collected by the selected filtering means;
- and
- control means associated with the selection means for controlling the supply of air from the air intake port to a predetermined at least one of said filtering means, said control means being operable to successively supply air from the air intake port to each of the filtering means for a predetermined time interval in accordance with a predetermined characteristic of a constituent of the air flow.
A method of continuously monitoring an air flow for the presence of a radiation-emitting material, comprising the steps of:
- directing the air flow to a first filtering means for filtering thereby for a predetermined active time interval;
- terminating the air flow to the first filtering means following lapsing of the predetermined time interval;
- directing the air flow to a second filtering means for air filtering thereby for a second predetermined time interval;
- maintaining the first filtering means out of the air flow to be monitored for a predetermined inactive time interval and measuring the level of the radioactive activity present on the first filtering means;
- and
- terminating the air flow to the second filtering means and directing the air flow to the first filtering means, wherein the predetermined active time interval is established in accordance with the half-life value of a predetermined air flow element.
Dependencies are inferred from the claim text.