The Fundamental Conductivity And Resistivity Of Water

By Truman S. Light, Stuart Licht, Anthony C. Bevilacqua, and Kenneth R. Morash

Pure water has a very low, but not quite zero, electrical conductivity. This conductivity provides a probe into fundamental properties of water, including the electrochemical mobility of the hydrogen and hydroxide ions. Deviation from this value is a measure of trace ionic impurities. Ultrapure water ~UPW!, with impurities at or below the sub-parts-per-billion range, is used extensively in many critical applications. Applications include chip fabrication for semiconductors, intravenous solutions for pharmaceuticals, and in highpressure boilers for power generation.