Location History:
- Elliottville, NY (US) (1984 - 1985)
- Salamanca, NY (US) (1989 - 1990)
- Frederick, MD (US) (1976 - 2007)
Company Filing History:
6 out of 14 
2 out of 2 
1 out of 1 Years Active: 1976-2007
Title: Innovations by John C. Dempsey
Introduction
John C. Dempsey is a notable inventor based in Frederick, MD (US), recognized for his contributions to the field of radiation monitoring technology. With a total of 10 patents to his name, Dempsey has made significant advancements in the measurement of radon progeny and gamma/X-ray radiation.
Latest Patents
One of Dempsey's latest inventions is the electret radon progeny integrating sampling unit (E-RPISU). This innovative device utilizes an electret ion chamber to measure radon progeny concentration effectively. The system employs a conventional 1 LPM particulate air sampling mechanism to collect radon progeny on a filter, which is then exposed to the chamber's interior. The alpha radiation emitted by the collected progeny ionizes the air within the chamber, allowing for precise measurement of radon progeny concentration through a specially built surface voltmeter.
Another significant invention is the electret gamma/X-ray low-level dosimeter. This device features a small enclosed ion chamber with an electrostatically charged electret attached to its inner wall. The chamber allows radon to diffuse in and out, while the ions formed by gamma radiation or X-rays collect on the electret surface. The reduction in the electret's surface voltage is directly proportional to the radiation dose, providing an accurate measurement of gamma or X-ray exposure.
Career Highlights
Throughout his career, Dempsey has worked with various companies, including Rad Elec Inc. and Taggents, Inc. His expertise in radiation monitoring has positioned him as a key figure in the development of innovative technologies in this field.
Collaborations
Dempsey has collaborated with notable individuals such as Lorin R. Stieff and Payasada Kotrappa, contributing to advancements in radiation measurement technologies.
Conclusion
John C. Dempsey's work in the field of radiation monitoring has led to significant innovations that enhance the accuracy and effectiveness of measuring radon progeny and gamma/X-ray radiation. His contributions continue to impact the industry positively.