Wavelength-integrated response function ℛ as a function of the logarithm of the optical depth at a reference wavelength of 500 nm, log τ₅, to the magnetic field strength B (top left), magnetic field inclination with respect to the observer line of sight γ (top right), temperature T (lower left), and line-of-sight velocity v_los (lower right). Red curves correspond to the integration over the observed spectral lines in this work (see Table 1), while the blue lines correspond to a wavelength integration over the Fe i line pair at 630 nm. The atmospheric model employed to calculate the response functions is the spatially averaged penumbral model obtained from the inversions (see Sect. 4.3).