With the lowering of the dust exposure limit values for workplaces arose the need for personal sampling systems designed to measure lower dust concentrations than before. The measurement of such small concentrations is impossible using today's personal sampling systems which are operated at flow rates between 2.0 and 3.5 l/min. Consequently, a new personal sampling system had to be developed allowing the determination of the inhalable and respirable dust fraction as defined in EN 481 "Workplace atmospheres: Size fraction definitions for measurement of airborne particles" even at low concentrations.
The flow rate was increased to 10 l/min which allowed for a lower detection limit. It became thus possible to measure lower concentrations than before. The GSP-sampling head, devised by BIA to sample the inhalable dust fraction, was modified: The suction opening was enlarged and the form of the suction cone optimised in a number of dust tunnel tests to enable sampling at 10 l/min. To sample the respirable dust fraction, a new cyclone was developed and also optimised in dust tunnel tests. Several personal sampling pumps and pump combinations were investigated to identify the most suitable one. Among these, one pump meets the requirements of use at a flow rate of 10l/min.
A new personal sampling system was developed which is operated at an increased flow rate of 10l/min; it can be used to measure lower dust concentrations than could be determined with the systems so far in use. The system is composed of three main elements: sampling head GSP 10 for sampling the inhalable dust fraction according to EN 481; sampling head FSP 10 for sampling the respirable dust fraction according to EN 481 and sampling pump GSM SG 10. As there is compatibility between the sampling head GSP 10 and the sampling head GSP 3.5 so far in use, filters and filter carriers do not need to be replaced. Compatibility exists also between the new FSP 10 and the formerly used FSP 2.
-cross sectoral-Type of hazard:
Meßverfahren, Chemische Arbeitsstoffe, ExpositionDescription, key words:
personal sampling, dusts, flow rate 10 l/min, dust concentrations