Flux density measurements from individual timing sessions (S_meas, coloured connected dots) for two out of the ten pulsars used for flux density uncertainty estimates. Separate grey dots are flux density values from the literature, with the errors estimated according to the procedure described in Sect. 5.2. The black line indicates S_lit, the parabola fit for literature flux density points within 10−1000 MHz. The shaded region marks 68% uncertainty on S_lit.