We describe an automated instrument for earthquake prediction research which monitors the emission of radon and thoron from rock. The instrument employs (1) aerosol filtration techniques and β counting to determine radon and thoron levels; (2) a programmable microcomputer which controls mechanical operations, collects data, and monitors the condition of key components; and (3) a call-up telemetry system for the transmission of data to a central location over standard telephone lines. Data from the field operation of the instrument is presented. © 1978.
Melvin, J. D., Shapiro, M. H., & Copping, N. A. (1978). An automated radon-thoron monitor for earthquake prediction research. Nuclear Instruments and Methods, 153(1), 239–251. https://doi.org/10.1016/0029-554X(78)90644-4