Abstract: A personal sampling method and apparatus for real time respirable dust dosimetry for dust exposure assessment is provided to aid in assuring the respiratory health of workers. An embodiment uses a low flow-rate gas sampling pump for differential pressure measurements across a glass fiber collection filter in a disposable detector tube (12) or dust detecting device coupled to the pump inlet. The dust detecting device includes an elongated tubular element (12) having the filter (30) positioned between proximal and distal ends of the tube (12) for trapping dust mass. A pressure transducer (16) at the proximal end (36) measures the pressure from the flow of gas. The pump draws the flow of gas through the dust detecting device from the distal end (38) towards the proximal end (36) trapping the dust mass at the filter (30).