INTERNATIONAL UNION OF PURE AND APPLIED CHEMISTRY MEASUREMENT OF pH. DEFINITION, STANDARDS, AND PROCEDURES (IUPAC Recommendations 2002) Working Party on pH

Republication or reproduction of this report or its storage and/or dissemination by electronic means is permitted without the need for formal IUPAC permission on condition that an acknowledgment, with full reference to the source, along with use of the copyright symbol ©, the name IUPAC, and the year of publication, are prominently visible. Publication of a translation into another language is subject to the additional condition of prior approval from the relevant IUPAC National Adhering Organization. Measurement of pH. Definition, standards, and procedures (IUPAC Recommendations 2002) Abstract: The definition of a “primary method of measurement ” [1] has permitted a full consideration of the definition of primary standards for pH, determined by a primary method (cell without transference, Harned cell), of the definition of sec