Comparison of Low Cost Miniature Spectrometers for Volcanic SO₂ Emission Measurements

Abstract: Miniature ultraviolet USB coupled spectrometers have become ubiquitously applied over the last decade for making volcanic SO₂ emission rate measurements. The dominantly applied unit has recently been discontinued however, raising the question of which currently available devices should now be implemented. In this paper, we consider, and make recommendations on this matter, by studying a number of inexpensive compact spectrometers in respect of measurement performance and thermal behaviour. Of the studied units, the Avaspec demonstrated the best prospects for the highest time resolution applications, but in the majority of cases, we anticipate users likely preferring the less bulky USB2000+s.