AS 2985:2009 pdf free

AS 2985:2009 pdf free.Workplace atmospheres – Method for sampling and gravimetric determination of respirable dust
Airborne concentrations of respirable dust in the workplace are determined by passing a measured volume of air through a filter of predetermined weight. By reweighing the filter at the end of the sampling period, the weight of material collected is determined by difference.To separate the respirable fraction, a size-selective sampler is used prior to the filter.The essential features of a sampling system are a filter (on which the sample is collected) and a pump for drawing the air through the filter. The filter shall be secured in a holder that prevents air from leaking around the edge of the filter. The filter shall be preceded by a size-selective sampler.
In personal sampling instruments, the filter holder/size selector is an integral unit that is located within the worker’ s breathing zone and this is connected to the pump unit (worn on a belt or in a pocket) by flexible tubing.
The respirable fraction shall be collected by using a size-selective sampler conforming to the sampling efficiency curve, see Clause 4.7. Such devices include miniature cyclones such as the BCIRA (British Cast Iron Research Association) Higgins and Dewell (see Appendix A，Reference 3) and Simpeds (Safety in Mines Research Establishment Personal Dust Sampler, Appendix A, Reference 4 and Figure 1) and aluminium cyclones (Appendix A, Reference 5) as in Table 2.
The filter size shall be chosen to suit the sampling head. Filters of 25 mm diameter are preferred, but a 37 mm diameter filter may be used.
Filters of nominal pore size of 5 μum or less shall be used. The type of filter material shall be chosen so that electrostatic charge, moisture variations, and loss of filter or sample do not significantly affect the analysis. In general, electrostatic charge problems have to be overcome with PVC and polycarbonate filters; significant moisture variations affect cellulose filters; loss of filter can occur with silver membrane and glass fibre filters. If polycarbonate filters are used, the nominal pore size shall be 0.8 μm or less. Care should be taken to ensure that there is no sample loss during use or transportation.
NOTE: For additional analysis (such as quartz or cristabolite) other factors such as filter type and treatment should be taken into account.AS 2985 pdf free download.