Determining the dustiness of powders--a comparison of three measuring devices.

The dustiness of 12 test powders was determined using three different measuring methods. One of the methods, the continuous drop method, is a reference test method according to the EN 15051 'Workplace atmospheres--Measurement of the dustiness of bulk materials--Requirements and reference test methods'. A test of equivalence between the reference test method and the other two methods, the modified Heubach Dustmeter, a rotating drum method and the Palas Dustview, a single-drop method, has been carried out as provided in Annex D of the European standard. No equivalence was found between any of the test methods. An applied best-case scenario yielded a slightly better outcome, but the results lead to the conclusion that it is impossible to generate viable values using the test of equivalence provided in the standard. This outcome was expected and is due to the different handling procedures applied-which, however, relates to the reality of the variety of material-handling procedures in the workplace.