Power spectrum calibration of the 280 GHz 2010 map. Top: In blue, 150s4 power spectrum and, in green, 150s4 × 280s4 power spectrum before the calibration (the latter has been displaced by l = 10 for visibility). For comparison we show the results from ACT Data Release 4 (Choi et al. 2020). Bottom: Ratio of the two spectra. The calibration factor derived from the weighted mean is shown as a red line.