Non-dispersive UV Absorption Spectroscopy: A Promising New Approach for in-situ Detection of Sulfur Dioxide

A new type of instrument for in-situ detection of volcanic sulfur dioxide is presented on the basis of non-dispersive UV absorption spectroscopy. It is a promising alternative to presently used compact and low-cost SO2 monitoring techniques, over which it has a series of advantages, including an inh...

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Bibliographic Details
Published in:Frontiers in Earth Science
Main Authors: Jan-Lukas Tirpitz, Denis Pöhler, Nicole Bobrowski, Bruce Christenson, Julian Rüdiger, Stefan Schmitt, Ulrich Platt
Format: Article in Journal/Newspaper
Language:English
Published: Frontiers Media S.A. 2019
Subjects:
Q
Online Access:https://doi.org/10.3389/feart.2019.00026
https://doaj.org/article/97ea57be8ab148f494c961b46a76af32
Description
Summary:A new type of instrument for in-situ detection of volcanic sulfur dioxide is presented on the basis of non-dispersive UV absorption spectroscopy. It is a promising alternative to presently used compact and low-cost SO2 monitoring techniques, over which it has a series of advantages, including an inherent calibration, fast response times (< 2 s to reach 90 % of the applied concentration), a measurement range spanning about 5 orders of magnitude and small, well-known cross sensitivities to other gases. Compactness, cost-efficiency and detection limit (< 1 ppm, few ppb under favorable conditions) are comparable to other presently used in-situ instruments. Our instrument prototype has been extensively tested in comparison studies with established methods. In autumn 2015, diverse volcanic applications were investigated such as fumarole sampling, proximal plume measurements and airborne measurements several kilometers downwind from the vent on Mt. Etna and White Island. General capabilities and limitations of the measurement principle are discussed, considering different instrument configurations and future applications.