KFM: A Homemade Yet Accurate and Dependable Fallout Meter.

摘要

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 30mR/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 step-by-step illustrated instructions for making and using a KFM are presented. 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. (ERA citation 03:029243)