DETECTOR SYSTEM FOR - RADIOMETER FOR LOW ACTIVITY

The invention relates to an instrument for rapid radiation control of a sample from the environment. Both radio chemically treated samples and samples without any radio chemical treatment can be measured. The detector system also enables the simultaneous measurement of the activity of the sample as well as the efficiency of the -radiation at a space angle 2 being the maximum possible. Its design is exceptionally compact and enables to produce sufficiently low background (under 1 pulse /min.) at maximum lead consumption (80 kg). The system is mounted on a stand with wheels enabling its easy travel at fairly short distances. It consists of two flow proportional counters having different diameters. The diameter of the protection counter has been selected sufficiently large in order to produce background counting speed smaller than 1 pulse/min. Technical mixture of argon-methane is used as working gas. The window of the measuring counter is covered by metallized foil 500 mg g/cm2 thick. The measuring and the protection counters are included in a circuit of anti-coincidence so that the simultaneous pulses of the two counters shall be excluded from the general pulse couting. It this way considerable part of the parricles of the solid space component shall not participate in the background couting speed.