The portable β-radiometer with composition of detector blocks for control contamination of external and inner surface tube with diameter 50 mm and charger have been developed. The main parameters of blocks detection - natural background, sensitivity to β- and γ-radiations and surface minimum measuring activity under different modes of radiometer operation were determined. The radiometer was tested in the real conditions for control of β-contamination of different diameter tubes.
Saltykov et al. (Sat,) studied this question.