A technique of measuring polarization in distilled water is described. The Luggin capillary and the a‐c‐d‐c bridge methods are discussed and judged inapplicable. The decay of polarization voltage (of aluminum) is shown to be relatively slow in this environment. A recording voltmeter and current interrupter suitable for making polarization measurements in low conductivity solutions are described. The important design features of the electrolytic cell are discussed, and polarization data for aluminum in boiling water are given as an experimental example.