Spectro-polarimetry at the Pic du Midi Turret Dome and new observations of the solar CaII K line

Abstract: We summarize in this paper the spectro-polarimetric methods used at the Pic du Midi Turret Dome in spectroscopic or imagery mode. The polarimeters and spectrograph allow the cartography of solar magnetic fields at high spatial resolution through the Zeeman effect or measurements of the unresolved turbulent magnetic fields in the quiet Sun through the Hanle effect. We describe in this paper the optical capabilities of the successive versions of the polarimeters operating since 2003, and we present new results of magnetic field analysis with the CaII K 3933.7 {\AA} spectral line.