pH 19 : Chemistry and Chemical Disasters. Numerical measure of acidity, with a scale of 0 to 14. Neutral is pH 7, values below 7 are acidic, and values above 7 are alkaline
EESiFlo North America, Terminology and Glossary: Water and Wastewater Terms, Pennsylvania, USA 2002. flowmeterdirectory.com/flowmeter_terminology, (Wtr and Wastewater - Amer) {559}