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 extremely useful for atmospheric studies but has a relatively high cost for both instrumentation and operation. We have developed an alternative system which maintains and improves operational features while being more compact. The main, novel feature of the proposed system is the denuder component, which has a large number of small hexagonal glass tubes sealed inside an outer glass tube. The new system has the following advantages: (1) both the initial cost and the labor required for processing 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 21 cm for the annular denuder, allowing a much more durable system; (3) this length also allows the use of several more denuders for simultaneous collection of a greater variety of gases; and (4) this new system is more convenient for large-scale monitoring studies. This paper presents the results from the performance evaluation of the impactor/honeycomb denuder/filter pack system. The tests include the impactor size cutoff determination, the honeycomb denuder efficiency and capacity measurements, and measurement of losses of acidic and basic gases on the sampler inlet surfaces.