Stokes Q/I amplitude as a function of limb distance μ = cos(θ). The Sr I data points represent the amplitude of a Gaussian fit to the Q/I line, while the Fe I data points are spectrally and spatially averaged values. We note that the scale is linear and that below μ = 0.2 less pixels were averaged for each data point. The S/N beyond μ = 0.7 is below two and therefore the fitted amplitudes are discarded. For comparison, a range of Sr I polarization values obtained by ZIMPOL and a stationary IRSOL polarimeter (magenta bars show the range of values) are taken from Stenflo et al. (1997).