In this work we analyze the applicability limits of the rotating ring-disk electrode (RRDE) technique for quantifying the amount of oxygen produced during the oxygen evolution reaction (OER). We utilize a state-of-the art IrO2 oxide as a carbon-free OER catalyst and La1-xSrxMn0.5Co0.5O3-delta, x = 0.25 and 0.5 perovskites, which are studied in the presence of carbon. RRDE experiments are performed at different IrO2 loadings under both potentiodynamic and potentiostatic modes. The experimental data allow us to formulate the requirements to the experimental conditions necessary to avoid underestimation of the oxygen yield. (C) 2018 Elsevier Ltd. All rights reserved.