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Silver plates were exposed to an urban atmosphere for one month to investigate the corrosion products formed in the early stages. After the exposure experiments, the corrosion products on the silver plates were characterized using x-ray techniques, including x-ray diffraction (XRD) and x-ray fl uorescence analysis (XRF). The XRD patterns of the corrosion products on silver revealed that both silver chloride (AgCl) and silver sulfi de (Ag 2 S) formed. The diffraction peaks originating from AgCl were much stronger than those of Ag 2 S; therefore, AgCl was predominant in the corrosion products observed on the outdoor-exposed silver. The chlorine that formed the AgCl originated primarily from sea-salt aerosols. The seasonal differences in the AgCl intensities in the XRD pattern could be observed. However, there was almost no difference in the Ag 2 S intensities. This was due to the low sea-salt concentrations and relative humidity during winter. Only Ag 2 S formed on the indoor-exposed silver. The absence of AgCl peaks in the XRD patterns indicated that the sea-salt concentrations were quite low in the indoor exposure site. Silver was found to be sensitive to the chloride in sea-salt aerosol and reduced sulfurous gases.KEY WORDS: atmospheric corrosion, silver, urban atmosphere, x-ray diffraction, x-ray fl uorescence analysis

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We proposed a new efficient sampling method for evaluating atmospheric corrosivity influenced by airborne sea salt and/or pollutants. X-ray Photoelectron Spectroscopy (XPS) was employed to analyze chlorine and sulfur captured in the top most thin layer of corrosion films. These elements are the main components of airborne sea-salt-par

Insulation failure in telecommunications cables after extended use in aerial terminal closures has been examined. Extensive cracking and sea salt deposition were ( ) observed on the polyethylene PE insulation of wires in a terminal closure recovered from the field after 27 years of service. The insulation failure mechanism appears to be the formation, by bulk water condensation with deposited sea salt dissolution on degraded PE insulation, of ionically conductive pathways among the PE insulation cracks. An experiment using wires with PE insulation that was deliberately cut to simulate cracking showed that controlling the humidity within the terminal closure is an efficient way to prevent insulation failure. A field experiment showed that placing a polymer that absorbs moisture when the humidity is high and releases it when the humidity is low in the closure effectively buffered changes in humidity, thus preventing water condensation. Another experiment using wires with deliberately cut insulation in a terminal closure with 100% RH and with the water-absorbent polymer placed inside showed that the resistance of the wires stayed at around 10 8 ⍀ without fluctuation. Since the absorbent polymer continues to function for many years, this proposed prevention method is well suited for practical application.