The human head as a dust sampler.

摘要: A life-size model human head and shoulders was exposed in a wind tunnel to winds between 0.75 2.75 ms/s particles up 30 micron aerodynamic diameter, the weight of material entering nose mouth at various breathing rates compared with that caught by isokinetic samplers. When aspirated constant rate, behaved like blunt sampler, showing ten-fold variation entry efficiency for different windspeeds directions, two-fold even 5 micron. Detailed facial structure had little effect. The efficiencies patterns minute volumes were calculated, when averages taken all simulate worker randomly oriented wind, lay within fairly small range, substantially less than 100%. "Total" dust standards samplers should take account these curves.