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Early Electroscopes at the National Bureau of Standards



Bert Coursey, Brian E. Zimmerman, Michael G. Mitch, Paul Frame


This report describes the use of five electroscopes used as national standards for radioactivity for the United States during the early 20th century. This set of instruments were used for the calibration of thousands of radium-226 sources used in medical therapy in the US from 1913 to 1989. The provenance of these instruments is recorded here to aid historians and curators in preservation of knowledge and artifacts of early radioactivity measurements in the United States.
Special Publication (NIST SP) - 1316
Report Number


Beta particle, electroscope, emanation, gamma rays, museum collections, radium, radon.


Coursey, B. , Zimmerman, B. , Mitch, M. and Frame, P. (2024), Early Electroscopes at the National Bureau of Standards, Special Publication (NIST SP), National Institute of Standards and Technology, Gaithersburg, MD, [online],, (Accessed June 25, 2024)


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Created May 17, 2024