| Mercury is metal pollutant that has very strong toxicity to the human body. People inbreathed mercury with fume form, which comes into brain, kidney, bowel, heart, lung, skin, mucosa of the breath way.The global atmospheric Hg deposition rate is approximately three times higher than in pre-industrial times. Exacerbation of mercury pollution is harm for people and environment. There are many kinds of mercury concentration evaluation method, but some are applicable to laboratory, some request longer sampling time or some instrument is huge or expensive. Therefore invent a real-time on-line mercury concentration evaluation method is necessary, which is cheap, small and practical.We analyze the spectrum 6s 2 1 S 0—6s6p 3P1 around 253.7nm, because atomic absorption only exits principal series connect with ground state.Based on Beer-Lambert law and Einstein transition theory, a concentration evaluation model was established. Based on the absorption spectrum characteristic of mercury, the system is made of deuterium lamp, high-resolution miniature fiber optic spectrometer, CCD detector and computer.Many effects to spectrum had been taken into account. It has no effect on system stability that changing light diameter, optical flux, integral time of the spectrometer. There is no saturated absorption around 253.7nm. That impact between air particles and mercury atom impels mercury atom transition and increases the absorption was developed. So air particles can't be change when measure the concentration. The effect of mercury shape to saturated concentration was studied: p r * (convex liquid level)> p r * (flat liquid level)> pr* (concave liquid level), the more short the radius of curvature became, the more far saturated concentration depart.
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