Improvements in or relating to methods and apparatus for continuous measuring of concentration of radioactive aerosols

摘要

917,238. Measuring radioactivity of aerosols. TESLA, NARODNI PODNIK. May 24, 1961 [June 1, 1960], No. 18723/61. Class 98 (1). In a method for measuring the concentration of a radioactive aerosol, the particles of the aerosol are concentrated in a filter 1 on to a deposition support 3 which then gradually moves along to a radiation detector 2; in addition to this unidirectional movement (T) the support also has a reciprocating movement (S). This reduces the dead time, i.e. the time which would elapse between a sudden change of concentration in the aerosol and its registration on the detector, without increasing the speed of the support. As shown, the deposition support is in the form of a strip 3, winding off a spool 4, passing the filter and detector, and then winding on to a spool 5. Suitable mechanisms are provided for giving the required movements to the strip 3. The reciprocating movement need not be continuous but intermittent. The speed of movement T may be very small compared with the speed of the reciprocating movement S.