[en] In 2011 the Polarized Antiproton eXperiments Collaboration has performed a successful spin-filtering test using protons at $T_p=49.3$ MeV at the COSY ring in Jülich, which allowed the determination of the spin-dependent polarizing cross section, that compares well with the theoretical prediction from the nucleon–nucleon potential and it confirms that spin filtering can be adopted as a method to polarize a stored beam. The document concentrates on the commissioning of the experimental equipment and the machine studies conducted to achieve the required beam lifetimes of $\mathrm{\tau <!--\; ??\; -->}=8000$ s in the presence of a dense polarized hydrogen storage cell target of areal density $d_{\mathrm{t}}=(5.5\pm <!--\; ??\; -->0.2)\times <!--\; ??\; -->{10}^{13}\mathrm{a}\mathrm{t}\mathrm{o}\mathrm{m}\mathrm{s}{\mathrm{c}\mathrm{m}}^{-<!--\; ???\; -->2}$. The developed techniques can be directly applied to antiproton machines and allow for the determination of the spin-dependent $\stackrel{¯<!--\; ??\; -->}{p}p$ cross sections via spin filtering. (paper)