Test No. 122: Determination of pH, Acidity and Alkalinity

This Test Guideline describes the procedure for the electronic determination of pH of an undiluted aqueous solution or dispersion, the pH of a dilution of a solution or dispersion in water, or the pH of a chemical diluted to end-use concentration. It also describes procedures to determine acid reserve or alkali reserve for a chemical that is acidic or alkaline with either strong or weak acid or alkali. The pH of an aqueous solution or dispersion in water is determined with a pH-meter equipped with an appropriate electrode system. The acidity or alkalinity of a solution or dispersion in water is determined by titration with standard acid or alkali using electrometric endpoint detection.