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Title: The KFM, A Homemade Yet Accurate and Dependable Fallout Meter

Technical Report ·
DOI:https://doi.org/10.2172/814086· OSTI ID:814086

The KFM is a homemade fallout meter that can be made using only materials, tools, and skills found in millions of American homes. It is an accurate and dependable electroscope-capacitor. The KFM, in conjunction with its attached table and a watch, is designed for use as a rate meter. Its attached table relates observed differences in the separations of its two leaves (before and after exposures at the listed time intervals) to the dose rates during exposures of these time intervals. In this manner dose rates from 30 mR/hr up to 43 R/hr can be determined with an accuracy of {+-}25%. A KFM can be charged with any one of the three expedient electrostatic charging devices described. Due to the use of anhydrite (made by heating gypsum from wallboard) inside a KFM and the expedient ''dry-bucket'' in which it can be charged when the air is very humid, this instrument always can be charged and used to obtain accurate measurements of gamma radiation no matter how high the relative humidity. The heart of this report is the step-by-step illustrated instructions for making and using a KFM. These instructions have been improved after each successive field test. The majority of the untrained test families, adequately motivated by cash bonuses offered for success and guided only by these written instructions, have succeeded in making and using a KFM. NOTE: ''The KFM, A Homemade Yet Accurate and Dependable Fallout Meter'', was published by Oak Ridge National Laboratory report in1979. Some of the materials originally suggested for suspending the leaves of the Kearny Fallout Meter (KFM) are no longer available. Because of changes in the manufacturing process, other materials (e.g., sewing thread, unwaxed dental floss) may not have the insulating capability to work properly. Oak Ridge National Laboratory has not tested any of the suggestions provided in the preface of the report, but they have been used by other groups. When using these instructions, the builder can verify the insulating ability of his materials by checking the leakage rate and comparing it to the author's leakage tests.

Research Organization:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
US Department of Energy (US)
DOE Contract Number:
AC05-00OR22725
OSTI ID:
814086
Report Number(s):
ORNL-5040; TRN: US0304159
Resource Relation:
Other Information: This report was originally published in January 1978; PBD: 20 Nov 2001
Country of Publication:
United States
Language:
English