Capturing Gas Fluxes on Your Phone: An iOS- and Android-based Data-Logging Setup for EGM-4 Environmental Gas...

Mobile devices have become increasingly important for field monitoring to improve data capture efficiency, increase storage capacity, and replace heavy equipment. We introduce a quick and straightforward protocol to capture greenhouse gas (GHG) emission rates on mobile devices. We developed our setup on the widely used infrared gas analyzer (IRGA) EGM-4 by PP Systems. This IRGA has a limited internal storage capacity and requires an external device such as a laptop to conduct even modest field sampling. Furthermore, when raw data storage is required, carbon dioxide concentration resolution is reduced by the internal EGM-4 software settings, making the equipment less suitable for high-frequency measurements. Our protocol lets the user bring either an iOS or Android mobile device in to the field to connect to the EGM-4's data stream. For both platforms, a mobile console application was used to read, log, and share flux data. The raw data can be processed in either Python, R, or Matlab using the provided scripts that give the user flexibility to amend further postprocessing steps to obtain GHG fluxes. We demonstrate the flexible applicability of mobile devices for field recording and show that a cost-effective solution can enhance the operational life of superseded field equipment while also increasing the quality of the captured data.