Rotorod Sampler (model 40) is volumetric, intermittent rotation impaction sampling device capable of quantitatively and qualitatively sampling airborne particles in the size range of 1 to 100 mm at sampling rates up to 120 litres of air per minute. The sampler consists of a constant speed motor of 2,400 rpm and two aerodynamically designed collector Lucite rods (1.3 mm in width), which are rotated by the sampler motor at 2,400 rpm. The retracting head holds two rods within the protective housing when the sampler is idle and when the sampler is activated; the rods are extended to a position perpendicular to the head. Rods are inserted in the pivot blocks and fastened with small thumbscrews (Fig. 13.6).
The particles are impacted on one face of the rod, which has been smeared with adhesive (glycerine jelly). It is exposed for one minute after every nine minutes of rest time when it remains folded and static. The exposed rods are mounted on a grooved stage adapter, which consists of four parallel grooves of approximately the same width of the rod. By placing a coverslip carefully the rods are microscopically examined thoroughly under 40 x objective and 10 x eyepieces. After correct identification of the trapped airborne fungal spores, their percentage frequency is expressed as numbers per m3 of air sampled.
Was this article helpful?