The Kearny Fallout Meter or KFM is an expedient radiation meter designed to be able to be constructed immediately before or during a nuclear attack by someone with a normal mechanical ability and from common household items. It also is a science project demonstrating the effect of ionizing radiation.
An electrostatic charge is placed upon two aluminium foil leaves. As radiation strikes the meter the foil leaves lose their charge and start to droop. This droop can be measured and a rate can be established.
The Kearny Fallout Meter was developed by Cresson Kearny from research performed at Oak Ridge National Laboratory and published in the civil defense manual Nuclear War Survival Skills (ISBN 0-942487-01-X). The plans were originally released in Oak Ridge National Laboratory publication ORNL-5040, The KFM, A Homemade Yet Accurate and Dependable Fallout Meter and have been formatted in a newsprint ready layout so that they may be quickly printed with accurate dimensions in local newspapers.