A new generation of test apparatus for aerosol samplers
Personal aerosol samplers are devices that measure the concentration of aerosols in the air, especially in occupational environments where the employees are exposed to potentially dangerous aerosols. Prior to their market release, these devices are tested in order that their effectiveness and accuracy can be validated. However, these tests require large-scale complex facilities as well as that they are time consuming and costly. A group of European research centres and universities active in the field of Aerosol Technology developed an innovative aerosol sampler test apparatus that overcomes the two main problems of the conventional systems; their size and the time required for the test execution. The consortium in order to reduce the size of the test apparatus as well as to reduce the time required, developed a new methodology for the computation of the fluid dynamics and the particle motion characterisation in small scales. According to this new methodology a novel test apparatus was developed which performs exactly the same tests while it is 5 times smaller. In the end, for evaluation purposes a number of commercial aerosol samplers are tested and the test data are compared with the ones derived from the conventional approach. The comparison analysis showed that with the new smaller system the same tests were performed with improved accuracy, better control of the test conditions such as air flow, homogeneity etc, requiring only one hundredth of the usual time. Finally, the reduction in terms of size and test's time is accompanied with a proportional cost reduction. While such a testing methodology presents an added advantage in its time and cost, the need for such test to produce accurate data comparable with conventional testing is important. However, the reduced sampling efficiency presented a drawback that will be addressed in further development and research, in that the concentrations of larger airborne particulate materials (greater than 15μm in aerodynamic diameter could not be accurately estimated.
