An automatic system for continuous monitoring of CO2, H2S, SO2 and meteorological parameters in the atmosphere of volcanic areas

An automatic system for the continuous monitoring of CO₂, H₂S, SO₂ and meteorological parameters in atmosphere has been developed. The system has been tested in the laboratory in order to verify the stability and reliability of each sensor and of the whole system. A field test for a period of one month, at the Solfatara of Pozzuoli has also been carried out. The acquired data during the field test reveal a correlation between the wind speed and the concentrations of CO₂, H₂S, and SO₂ in the atmosphere. With a wind speed of over 4 ms^-1 the concentration of the three gases reached constant background values of 600 ppm for CO₂ and about 2 ppm vol. for H₂S and SO₂. The different ratios of H₂S/SO₂ measured in the fumaroles (~100) and in the atmosphere (1–0.1) clearly indicate that H₂S is oxidized to SO₂ during the transport.