A profile generated with β = 5.4905,θ_s = 1.8 (the universal profile, black lines) can be mimicked for β = 8.9 using θ_s = 4.1 and adjusting Y_tot downward (red lines). The two profiles are almost identical over the AMI-SA range of baselines, while Planck would measure the zero-spacing flux which differs by ≈7% between the two models. a) Shows the pressure profiles in radial coordinates (note that the y-axis scale is log); and b) shows the profiles in uv-space for channel 5, with the simulated AMI data shown as dots. Note that this simulation has been generated with an unrealistically small amount of thermal noise.