High-purity water is frequently used in many water treatment applications to avoid possible contaminations caused by water impurities. Measuring the pH of this water is challenging and necessitates specialized equipment.

pH measurement in high purity water is challenging for various reasons. The low conductivity of pure water in combination with the vulnerability to contamination, the variability of reference electrodes and additional temperature effects converge to make this a particularly challenging measurement. Overcoming these obstacles requires a thorough understanding of the potential problems and their systematic solution.