Monitoring air fluxes in caves using digital flow metres

Authors

Claudio Pastore, Swiss Institute for Speleology and Karst Studies (SISKA), La Chaux-de-Fonds, SwitzerlandFollow
Amir Sedaghatkish, Swiss Institute for Speleology and Karst Studies (SISKA), La Chaux-de-Fonds, SwitzerlandFollow
Eric Weber, Swiss Institute for Speleology and Karst Studies (SISKA), La Chaux-de-Fonds, SwitzerlandFollow
Nicolas Schmid, Swiss Institute for Speleology and Karst Studies (SISKA), La Chaux-de-Fonds, SwitzerlandFollow
Pierre-Yves Jeannin, Swiss Institute for Speleology and Karst Studies (SISKA), La Chaux-de-Fonds, SwitzerlandFollow
Marc Luetscher, Swiss Institute for Speleology and Karst Studies (SISKA), La Chaux-de-Fonds, SwitzerlandFollow

Highlights

• Low-cost and lightweight digital flowmeter tested for the automated monitoring of air fluxes in caves
• Numerical modelling reveals inhomogeneous velocity distribution in a cave passage
• Recommendation for the positionning of instruments in air streamlines

Abstract

Precise measurements of airflow within caves are increasingly demanded to assess heat and mass transfers and their impacts on the karst environment, including subsurface ecosystems, hydrochemistry of karst water and secondary mineral precipitates. In this study, we introduce a new, low-cost and lightweight device adapted to monitoring air fluxes in caves which addresses the need for reliable measurements, low power consumption, durability and affordability. The device was calibrated in a wind tunnel, showing the high accuracy and precision of the device. Field-related uncertainties were further investigated in a ventilated cave to determine the effect of local airflow conditions on the inferred mass flux. Comparing measured values with a 3-D air velocity distribution modelled on a surveyed cave section suggests that most of the uncertainties in estimating the airflow result from the relative position of the instrument in the streamlines rather than from the accuracy of the device.

DOI

https://doi.org/10.5038/1827-806X.53.1.2500

Creative Commons License

This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 4.0 License.

Recommended Citation

Pastore, C., Sedaghatkish, A., Weber, E., Schmid, N., Jeannin, P.-Y., Luetscher, M., 2024. Monitoring air fluxes in caves using digital flow meters. International Journal of Speleology, 53(1), 63-73. https://doi.org/10.5038/1827-806X.53.1.2500