Determination of Environmental Or Occupational 222Rn in Air and Water and 226Ra in Water With Feasible and Rapid Methods of Sampling and Measurement

Abstract

For air-sampling 30-l. containers of flexible foil are taken to the sites. To measure the ²²²Rn and ²²⁶Ra content of water, special bottles are used with volumes of 0.5 and 2.51. respectively. All samples are measured in the laboratory. In this way it is possible to take a great number of samples at the sites considered, which is necessary to obtain significant annual mean values. The measuring equipment consists of a 10–20 l. ionization chamber in connection with an electronic electrometer and a chart-recorder. The air sample is transferred very fast into the evacuated chamber, so that one can define the zero-point for the increase in ionization current due to the short-lived decay products. The radon content of a water sample is also transferred as fast as possible into the chamber with inactive air streaming through a de-emanating bottle. Changeable central electrodes keep the background low and permit a rapid succession of measurements. For the determination of small ²²⁶Ra contents a double-chamber equipment with background compensation is used.