Measurements of electric charge associated with evaporation and condensation of water on metallic surfaces as a consequence of pressure, humidity, and temperature change

Existence of a previously unreported flow of small current to and from a metallic electrode surface during transient air pressure change is reported and described. Measurements of transient current, humidity, and temperature with transient air pressure change are presented. The flow of electrode current is shown to be not due to capacitance and input offset voltage changes, since the calculated value is on the order of 10(-16) A which is much less than the measured currents of order 10(-13) A. Measurements using air of different levels of humidity and with dry nitrogen confirm that zero moisture results in essentially zero current, and that the amplitude of the current increases with increasing humidity. (c) 2005 Elsevier B.V. All rights reserved.