Fast-sampled signal from bolometer 143-1a. Left: eighty samples from early in the mission, corresponding to one cycle of the 90-Hz square-wave modulation of the bias current across the bolometer. Because of the square-wave modulation, the first and last sets of 40 samples are nearly mirror images of one another across the x-axis. The units are raw analogue-to-digital units (ADU). Middle: normalized histogram of the fast-sample signal values for day 91 of the mission, in ADU. The signal spread is dominated by the combination of the noise and the square-wave modulation of the bias current across the bolometer (left panel), with additional contributions from the CMB solar dipole. Right: normalized histograms for each day, starting with day 91, stacked left to right for the entire mission. Histogram values are given by colour, as indicated. The obvious symmetric trends during the mission are caused by drifts in temperature of the bolometer plate. Isolated days with large deviations from zero, seen as narrow black vertical lines, are due to solar flares.