pH 27 : Chemistry and Chemical Disasters. The negative logarithm of the hydrogen ion activity. pH = -log10 (aH+) Measurement of acid (<7), basic (>7), neutral = 7. pH measures the acifdity or alkalinity of water
George E. King Engineering, 5000 Oilfield Terms: A Glossary of Petroleum Engineering Terms, Abbreviations and Acronyms, US 2010. http://gekengineering.com/Downloads/Free_Downloads /Glossary_of_Petroleum_Engineering_Terms_25_August _2010.pdf, (Oil - Amer) {593}