A probe has been developed based on the quartz crystal microbalance to monitor changes in outdoor corrosivity during in situ conditions. The atmospheric corrosivity probe has been used for outdoor exposures of gold, silver and copper at different sites with simultaneous
measurements of atmospheric corrosion stimulators. Two measurement systems have been tested, one using a monosensor and the other a multisensor. The precision in mass measurements is +- 10 ng/cm2 and corresponds to sub-monolayer sensitivity. Exposures of gold
demonstrated the importance of naturally occurring deposition of aerosol particles, which turns out to have a strong influence on the time of wetness of the gold surface. Exposures of copper could be calculated into mass increase rates and revealed information on the episodic nature of copper corrosion and on the relative influence of the corrosion stimulators measured.
Key words: quartz crystal microbalance, probe, outdoor exposure, corrosivity, atmospheric corrosion, copper, silver, gold, aerosol particles, sulfur dioxide, nitrogen dioxide, ozone.