Standard Test Method for pH of Engine Coolants and Antirusts
pH is a measure of the hydrogen ion concentration and indicates whether an engine coolant, antirust, or a solution of these compounds is acidic, alkaline, or neutral. The pH range includes values from 0 to 14. Values from 0 to 7 represent the acidic half of the scale. Values from 7 to 14 represent the alkaline or basic half of the scale. The pH value 7 is considered neutral, as it is neither acidic nor alkaline. pH is sometimes used for production quality control. It is generally desirable that engine coolants have an alkaline pH.
