The first function handles output files from a LI-820 to generate a dataframe of the sample details (file name, date-time, slope (k), mean temperature (of the optical path) and mean pressure. Note that the temperature measured by the LI-820 is that across the optical path and is not appropriate for calculating the CO2 efflux. The temperature of the system must be measured separately. The second and third functions calculate CO2 efflux according to eqns 7 and 9, respectively. When used please give credit to Dossa, G. G. O., Paudel, E., Wang, H., Cao, K., Schaefer, D. and Harrison, R. D. (2015), Correct calculation of CO2 efflux using a closed-chamber linked to a non-dispersive infrared gas analyzer. Methods Ecol Evol, 6: 1435–1442. doi:10.1111/2041-210X.12451