The X‐Y pulsed measuring system developed at the Naval Research Laboratory by Haas and Harris was modified and used in the study of electrochemical systems. By means of a versatile pulse generator and a modified double sweep oscilloscope, a highly flexible system giving accurate control of pulse rise time, repetition rate, length, amplitude and delay makes it possible to determine the electrokinetic parameters of fast reaction steps. An investigation of the hydrogen reaction on platinum in acid solution resulted in a quantitative separation and determination of solution resistance, charge on the double layer, and the discharge/ionization reaction step.