[en] The chemical reaction products caused by polarization at each electrode were identified. Chronopotentiometry was then used to ascertain the limitations on current density to avoid polarization. Because the polarization effects are cumulative and sufficient time must be allowed for solution re-equilibration, maximum duty cycles were determined for various current densities and CuSO₄ concentrations. Accelerated life tests were also performed with actual PBFA-type resistors. The tests showed that the chronopotentiometric experiments produced somewhat conservative guidelines for operating the resistors oriented with the cathode up. It was also shown that, with horizontal or cathode-down operation, a significantly longer current pulse can be endured without leading to resistor failure