SO2 Monitoring With Solid State-Based UV Spectroscopy Compact Apparatus

We propose a solid state-based spectroscopy
compact apparatus for monitoring environmental SO2, particularly
suitable, for example, for volcanic applications. A prototype
system, with a 170-mm long optical path, was assembled and
tested using a commercial LED operating at 285 nm and a
large area silicon carbide. The laboratory tests were carried
out using calibrated quartz cuvettes containing SO2 at fixed
concentrations and standard SO2 gas with 20% of O2 and
complemented with N2 dry gas to fill the optical system chamber.
Optical signal attenuations in the chemically interactive chamber
follow the Beer-Lambert-Bouguer law in all the performed tests
and a 0.16 ppm/pA nominal chemical resolution and ± 0.8 ppm
concentration error were obtained from the experimental data
for the current prototype.