We developed an Android app, called Flux Puppy, to facilitate chamber-based CO2 and H2O flux measurements in the field and laboratory. The app is designed to run on an inexpensive handheld Android device, such as a tablet or phone, and it has a graphical user interface that communicates with a LI-COR LI-820 and LI-830 (CO2) or LI-840 and LI-850 (CO2/H2O) infrared gas analyzer. The app logs concentrations of CO2 and H2O, cell temperature and pressure at 1 Hz, displays the output graphically, and calculates the linear regression slope, R-squared, and standard error of the CO2 time series. A metadata screen allows users to enter operator, site, and plot information, as well as take a photograph using the Android device’s built-in camera, and log measurement location using the device GPS. Additionally, there is a notes field, which can be revised after the measurements are taken. Data files (the 1 s raw data, photograph, and metadata including statistics calculated from the raw data) are then transmitted off the device through file sharing options (Gmail, Outlook, Google Drive, Dropbox etc.). Because Flux Puppy code is open-source (available on GitHub) and the flux measurement system we describe is relatively inexpensive and straightforward to assemble, it should be of broad interest to the carbon cycling community.
The paper describing Flux Puppy and the design of a low cost system is:
Flux Puppy v1.0.0 is written in Java and designed in Android Studio.
The current tested and stable release is available for download at http://doi.org/10.5281/zenodo.1413689
The development stage source code, UML, and quick start user guide are available from the GitHub Inc: https://github.com/bnasr/FluxPuppy.
This app is freely available, documented, and can be modified to the user’s needs.
If you use Flux Puppy, let us know, and we will send you a sticker!