DEVELOPMENT AND EVALUATION OF A GLASS HONEYCOMB DENUDER FILTER PACK SYSTEM TO COLLECT ATMOSPHERIC GASES AND PARTICLES

Currently available annular denuder/filter pack technology has been ex tremely useful for atmospheric studies but has a relatively high cost for both instrumentation and operation. We have developed an alternati ve system which maintains and improves operational features while bein g more compact. The main, novel feature of the proposed system is the denuder component, which has a large number of small hexagonal glass t ubes sealed inside an outer glass tube. The new system has the followi ng advantages: (1) both the initial cost and the labor required for pr ocessing are much less than those of the annular denuder; (2) a length of only 3.8 cm yields the same collection capability as a length of 2 1 cm for the annular denuder, allowing a much more durable system; (3) this length also allows the use of several more denuders for simultan eous collection of a greater variety of gases; and (4) this new system is more convenient for large-scale monitoring studies. This paper pre sents the results from the performance evaluation of the impactor/hone ycomb denuder/filter pack system. The tests include the impactor size cutoff determination, the honeycomb denuder efficiency and capacity me asurements, and measurement of losses of acidic and basic gases on the sampler inlet surfaces.