Effective calibration factor of the large-scale sensitivity calibration as a function of time for an example calibration unit. The calibration unit is the same as in Fig. 2, as are the vertical lines. For this plot, the detailed colour terms of thecalibration model have been combined to form an effective calibration factor using default colours. This is necessary since there is no constant term in the calibration model equivalent to a zeropoint. See Carrasco et al. (2016) for more details.