Normalized histograms of the correlation coefficients of the 10 and 30 Hz 4-K line amplitudes. The amplitude is computed per ring and per bolometer from the two coefficients (sine and cosine) of a given line. For each pair of distinct bolometers (from 100 to 353 GHz), a correlation coefficient is computed between the two amplitudes during the mission. The black normalized histogram shows the 10 Hz line correlation coefficients of the 903 (= 43 × 42 / 2) pairs. The red curve shows the 30 Hz line histogram. The 30 Hz line is clearly correlated between different bolometers. This is the only line that shows a significant correlation.