An automatic system for continuous monitoring of CO₂, H₂S, SO₂and meteorological parameters in the atmosphere of volcanic areas

Abstract

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.