Detection of SF₆ characteristic decomposition component H₂S by cavity ring-down spectroscopy

H
2
S is one of the characteristic decomposition components in SF
6
. The detection of H
2
S concentration by optical cavity ring-down spectroscopy is of great value to the evaluation of equipment insulation state. Based on distributed feedback semiconductor laser (DFB), an optical cavity ring-down spectrometer (CRDS) was built to measure the hydrogen sulfide content in SF
6
gas by measuring the absorption spectrum of hydrogen sulfide at 1.578μm. The effect of characteristic decomposition products of SF
6
on the detection results of hydrogen sulfide was studied. The results show that the absorption spectra of CO
2
and CO molecules overlap with H
2
S at 1.578 μm, which makes the presence of CO
2
and CO in SF
6
gas more difficult to detect H
2
S. CO
2
and CO concentrations are important factors affecting the detection results of H
2
S. With the decrease of CO
2
and CO concentrations, the detection error of H
2
S decreases.