Measurements of fibrogenous dusts using the VC 25

For routine measurements and assessments of fibrogenous dusts the Dust Research Institute (Staubforschungsinstitut), together with the technical supervisory services of the social insurances for trade, has, since 1973, been using a new measuring system. It consists of the sampling device VC 25 (which can be used selectively for the determination of respirable dust or of total dust), of an evaluation instrument based on the β-ray absorption principle (147Pm), and of a filter holder for sampling, transporting, and evaluating. This system makes it possible to carry out a decentralized sampling and a centralized evaluation, including the analysis of noxious substances and the collection of data. At the present, one evaluation station can attend to 50 sampling devices. In 1975, a total number of 3,500 dust measurements will be evaluated. Practical experience, limits of application, and possibilities of improvement are reported, as are the results of comparative tests by other methods. (orig.)