Measurement of the sampling efficiency of personal inhalable aerosol samplers using a simplified protocol

Traditional protocols for the performance evaluation of personal inhalable aerosol samplers utilize full-size manikins and large cross-section wind tu nnels. Thus, these sampler evaluation procedures are complex, very costly, and time consuming. In addition, it is difficult to provide an adequately u niform wind velocity and aerosol concentration over large cross-section win d tunnels. A simplified test protocol, developed in our recent studies, is evaluated in this paper. The protocol is based on a three-dimensional recta ngular simplified torso that simulates the dimensions of the human chest. T his arrangement allows simultaneous measurement in four discrete orientatio ns to the wind, thus providing useful orientation-dependent sampler informa tion and possibly reducing the number of measurements needed. Sampling effi ciencies of four personal inhalable aerosol samplers (the IOM, GSP, 37-mm c losed-face cassette, and the button sampler) were measured using the simpli fied test protocol and the traditional approach for three particle sizes (7 , 29, and 70 mu m) in four inlet orientations to the wind (0, 90, 180, and 270 degrees) and two wind velocities (0.5 and 2.0 ms(-1)). It was found tha t when these samplers were mounted on the simplified torso versus the full- size manikin, the sampling efficiencies responded to changes in the samplin g conditions in the same way regardless of whether the samplers were mounte d on the simplified torso or the full-size manikin. Also, the sampling effi ciencies were found not to be statistically different when the samplers wer e mounted on the simplified torso versus the full-size manikin. Thus, the s implified test protocol was shown to be suitable for the performance evalua tion of personal inhalable aerosol samplers. (C) 1999 Elsevier Science Ltd. All rights reserved.