Thermo Scientific Model 450i Hydrogen Sulfide analyzer
This analyzer uses pulsed fluorescence technology, and according to the manufacturer it as a detection limit of up to 0.5 ppb (with 300 seconds averaging times), altough it can average every 10 seconds wit a 2 ppb detection limit. The Thermo Scientific TM Model 450i analyzer operates on the principle that H 2S can be converted to SO2. As the SO2 molecules absorb ultraviolet (UV) light and become excited at one wavelength, the molecules then decay to a lower energy state emitting UV light at a different wavelength.