In some cases, e.g. when using a new instrument that was never used before, it is not known in which team window the maximum covariance between tubulent wind and the scalar of interest (CO2, H2O, etc…) should be searched.Therefore, it is recommended to first search for lag times in a relatively large time window (“open-lag run”) and check the histogram of found lag times and whether any peak in the distribution can be seen. Then – for the final flux calculations – search the lag again in a smaller time window. The smaller time window is defined according to the histogram of found lag times from the open-lag run. The peak of the histogram can be used as the nominal / default lag time in EddyPro (used when no clear maximum covariance was found).