Abstract: A small, compact, portable air sampler, for wearing by an industrial worker to monitor the nature of the air breathed by the worker during work shifts, comprises an air filter and a pumping means adapted to draw a known volume of air through the filter on each stroke of the pumping means. The pumping means is controlled to draw air through the filter intermittently, at pre-selected intervals. An electronic clock determines the intervals, and a memory is provided to record the number of pumping strokes made during the period in which the instrument is worn by the worker, so that the total volume of air drawn through the sampler is known. The electronic controls and a power pack, along with the filter, pumping means and driving means, are all included in a housing, to provide a self-contained, miniaturized unit. A pocket clip is provided, for attachment to a wearer's clothing, with an electric switch which closes when the sampler is worn. Only when the switch is closed will the air sampler draw in air.