Thermal SZ spectrum (continuous line in bottom panel), compared to the atmospheric transmission of a dry, cold, atmosphere (top panel, PWV = 0.5 mm), and to spectra of the non-thermal SZ effect (dotted line), of CMB anisotropy and kinematic SZ (dashed line), and of dust anisotropy (dot-dashed line). The parameters of the different spectra are for the benchmark case detailed in Sect. 2: τ_t = 5 × 10^-3, T_e = 8.5   keV, ΔT_CMB = 22   μK, τ_nt = 1 × 10^-4, α = −2.7, p₁ = 1.4   MeV/c, ΔI_d(150   GHz) = 600   Jy. The frequency coverage of the different experiments considered in the paper is also shown as dotted horizontal lines, labelled with the experimental configuration number.