| 摘要 |
PURPOSE:To measure nitrogen oxides and sulfur oxides in atmospheric air accurately for a long time without the use of a costly apparatus, by sampling a poisonous gas in a sample air through a porous plate and a resin film interposed between the sample air and an absorbent. CONSTITUTION:A stationary type gas sampler comprises a porous plate section 3, a film 4, an absorbent 5 and a water retaining section 7. It is also made up of a body 1 in which joints between sections are kept airtight against outside air and four legs 2. The porous plate 3 is a disc with the outer diameter of 30-70mm and provided with 4-100 gas diffusion pores 8 with the diameter of 1-10mm and the depth of 3-18mm. A resin film 4 with the thickness of 25-150mu is put tightly at the lower part thereof and employs a filter paper impregnated with triethanol amin as absorbent 5. Moreover, when the sampling exposure period exceeds 10 days, the water retaining section 7 is provided through a film 6 to hold the atmosphere of the absorbent 5 on fixed moisture conditions and then, a sampling is performed.
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