Abstract： AS 2985:2009 pdf download.Workplace atmospheres—Method for sampling and gravimetric determination of respirable dust. 5 PRINCIPLE Airborne concentrations of respirable dust in the workplace are determined by passing a measured volume of a...

AS 2985:2009 pdf download.Workplace atmospheres—Method for sampling and gravimetric determination of respirable dust.

5 PRINCIPLE

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.

6 APPARATUS

6.1 Sampling systems

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 ithin the worker’s breathing zone and this is connected to the pump unit (worn on a belt or in a pocket) by flexible tubing.

6.2 Sampling device

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 B(’IRA (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.

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