Method of testing rainfall to determine its radioactivity of rainfall and apparatus for performing the method

摘要

1,085,183. Determining the radioactivity of rainfall. COMMISSARIAT A L'ENERGIE ATOMIQUE. Aug. 24, 1965 [Sept. 1, 1964], No. 36316/65. Heading G1A. Rain from a rain gauge 4, Fig. 1 (not shown) collected in a reservoir 8 is controlled in its flow through a # radiation gauge 12 by an electromagnetically driven pump 20 the operation of which is controlled in direct proportion to the level of water in the reservoir or to the maximum level achieved at any time since the reservoir was last emptied. The electromagnetic driving mechanism 22 is energized through a thyratron 46 in response to the actuation of a monostable multi-vibrator 44 by pulses from a voltage to frequency converter 42, the voltage being obtained from a store 40 the input of which is derived from a reservoir pressure transducer 26. The maximum pulse rate from converter 42 is such that the period between pulses exceeds the multi-vibrator operating time. The operation is initiated and terminated by a water presence detector in the reservoir, the terminating pulse resetting the store. A y radiation detector is included in a second reservoir through which the water is pumped and the detector outputs are taken to respective counters. The volume of water evacuated is measured to enable the specific total radioactivity to be determined. The level signal storage circuit may be omitted. A lead shield is provided around the # detector.