Development of radometer based on silicon detectors with a big sensitive area

The paper presents the results of the development of manufacturing technology, as well as some data from studies of the electro physical and radiometric characteristics of semiconductor surface-barrier and hetero-transition Al-$\alpha$Ge-pSi-A detectors of large sizes (10 cm in diameter). In addition, the monitoring data of the radon concentration in the subsoil and in the air are presented. The monitoring results showed that the concentration values vary depending on temperature, humidity and time of day.