[Determination of weight concentration of dusts using automatic sample-collecting devices based on beta absorption and on the Tyndall effect].

Some automatic sample-collecting sets for measuring the ponderal concentration of dust have been tested. Such apparatuses are based on two different principles: beta ray absorption, and Tyndall effect. It is shown how, through the beta absorption apparatus, it is also possible to carry out absolute measurements, after evaluating obviously the possible matrix effects. Furthermore it is shown how the sample-collecting sets, based on Tyndall effect, open new prospects in their employement on machinery drainage processes, or in following the behaviour of dust phenomena. The two types of apparatus thus tested integrate each other, where an automatic control, particularly in working environments, is needed.