Sampling and recording dose rate meter
AssigneeThe United States of America as represented by the Secretary of the Army
InventorStanley Kronenberg
Life of this patent
Estimating the term…
Abstract
A wide range radiation dose rate meter for civil defense use, including a iger-Mueller tube used in a continuous counting mode and for measuring dose rates from the natural background to about 30. rads/hr., with an ion chamber arranged to measure higher dose rates up to 10,000 rads/hr. The instrument has a sample and record capability in which the selected radiation detector will have its output connected to a selected storage capacitor for a precise interval of time determined by a timing circuit and the storage capacitor will accumulate and hold a voltage proportional to the dose rate, which can be read by means of an electrometer at a later time. The instrument has a self contained hand cranked power supply and all components are selected for long shelf life.
Claims9
A hand-held dosimeter comprising:
- a hand cranked generator;
- radiation detector means including a first Geiger-Mueller tube detector filled with a first type of gas mixture and a second ion chamber detector filled with a second type of gas mixture, said Geiger-Mueller tube having an enclosure which contains said first type of gas mixture and separates said first type of gas mixture from said second type of gas mixture;
- first switching means for selectively connecting the output of said generator to one of said first and second detectors;
- timing circuit means energized by said generator for providing a precise predetermined sampling interval;
- an electrometer connected to said timing circuit means;
- second switching means for selectively connecting the output of said first and second detectors to said electrometer and said timing circuit means to selectively energize said electrometer;
- a plurality of storage capacitors selectively coupled in parallel with said electrometer for receiving the charge accumulated thereon;
- said dosimeter having three modes of operation, the first mode being a charge and continuous counting mode in which the output of said Geiger-Mueller tube is continuously applied via said second switching means to said electrometer, the second mode being a high sensitivity dose rate measuring mode in which the output of said Geiger-Mueller tube is applied via said second switching means to said electrometer and to said plurality of storage capacitors, and the third mode being a low sensitivity dose rate measuring mode in which the output of said ion chamber is applied via said second switching means to said electrometer and to said plurality of storage capacitors.
Dependencies are inferred from the claim text.