A quartz crystal microbalance probe developed for outdoor in situ atmospheric corrosivity monitoring

In order to perform in situ monitoring of minute corrosion attacks during outdoor field exposures, an atmospheric corrosivity probe has been developed based on the quartz crystal microbalance. A remotely controlled computerized mobile field station was also constructed. The whole setup allows simultaneous in situ measurements of mass changes with a resolution of +/- 10 ng cm(-1), and of climatic parameters. The observed mass changes during introductory exposures of gold and copper in an urban atmosphere are both reversible and irreversible. Aided by ex situ x-ray photoelectron spectroscopy analysis, the results can be interpreted in terms of salt deposition, water adsorption, water desorption, and atmospheric corrosion effects.