A Microprocessor Based Mobile Radiation Survey System

A microprocessor-based system has been designed and constructed to enhance the performance of routine surveys on roads within the Hanford site. This device continually monitors system performance and output from four sodium iodide detectors mounted on a 4-wheel drive truck. The gamma radiation count rate in counts-persecond is monitored, and a running average computed, with the results compared to predefined limits. If an abnormal instantaneous or average count rate is detected, an alarm is sounded with responsible data displayed on a liquid crystal panel in the vehicle´s cab. The system also has the capability to evaluate detector output using multiple time constants and to perform more complex tests and comparison of the data. Data can be archived for later analysis on conventional chart recorders or stored in digital form on magnetic tape.