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[[File:Dust collector.jpg|thumb|500x500px|A highly speculative image of an array of dust collectors feeding atmospheric compressors on Mars. Sized for 50 m3/s of martian air, or about 1 kg/s.]]
A dust collector is a device used to separate dust from air.
In some cases clean air is the desired result, in others, the dust is the object of interest.

Most dust collectors operate below atmospheric pressure with the fan on the clean side, after the dust separation system. In the thin martian atmosphere, the available pressure is very low, much lower than the standard operating pressure of dust collectors.  So the fan might be required to be put on the dusty side, before the filters.

Dust collectors are filtration systems.  For effective filtration of small particles they will often operate in cascade fashion, with a pre-filter and secondary filters.
HEPA grade filters can filter down to 5 microns, removing bacteria.  However they have no effect on gases, only dust and particulate matter.