A Sensor System for High Resolution In Situ Atmospheric Corrosivity Monitoring in Field Environments

Abstract

In order to investigate episodic changes in atmospheric corrosivity with a high time resolution, a new sensor system for in situ field studies has been developed. Atmospheric corrosivity probes, based on the quartz crystal microbalance technique, are used together with probes for temperature and relative humidity and analyzers for H2S, SO2, NO2, and 03. To demonstrate the capability of the sensor system, an indoor field characterization has been conducted in an electrical control room within a pulp and paper factory. The characterization included simultaneous exposures of gold, silver, and copper together with gas analysis during normal operation and simulated malfunctions of the air filtration system. The precision of in situ mass response measurements has a standard deviation of only 1 ng cm2, corresponding to a mass sensitivity of less than one equivalent monolayer of corrosion products, e.g., Cu3O. The mass sensitivity enabled differences in mass increase rates of copper, silver, and gold to be detected within hours after exposure start in normal operating conditions and on silver within minutes after simulated malfunctions of the air filtration system.

Influence of UV irradiation and ozone on atmospheric corrosion of bare silver

“…Atmospheric corrosion of silver was observed only in the presence of moisture, and the amount of moisture adsorbed on silver surface was a function of RH. [9][10][11] However, Rice et al 12 observed that the atmospheric corrosion rate of silver was insensitive to RH over the range of 30-80% in lab chamber environments consisting of purified humid air containing predetermined quantities of SO 2 , NO 2 , H 2 S, Cl 2 , HCI, NH 3 and O 3 . This lack of RH dependence was attributed to direct chemical attack of Ag by H 2 S. The deposition of airborne environmental pollutant particles on the surface also plays an important factor in the atmospheric corrosion of silver.…”

Corrosion Monitoring in Atmospheric Conditions: A Review

“…The quartz crystal microbalance (QCM) is a mass sensor first suggested for this purpose by Sauerbrey in 1958 [131]. It has been developed for corrosion monitoring in 1990s' [132][133][134]. The technique is standardised [135].…”

Atmospheric Corrosivity Estimation at Electrical Control Unit Room by Multichannel Quartz Crystal Microbalance Corrosion Sensors

“…For instance, a copper migration occurred although the atmosphere in the electrical control room of a steelmaking plant was moderately corrosive. 5) By combining a quartz crystal microbalance (QCM) 6) and gas analyzer, Forslund et al 6) monitored the atmospheric environment in the paper manufacturing plant and illustrated a correlation between the metallic corrosion rate and the corrosive gas concentration fluctuation pattern. On the other hand, Todo et al 7) analyzed the correlation of measured copper corrosion with the atmospheric temperature, relative humidity, corrosive gas concentration, and airborne sea salt particle concentration.…”

“…In fact, QCM was used for metal corrosion monitoring at the telephone exchange room, 8) at electrical control unit room in steelworks plant, 5) and at the paper manufacturing plant. 6) In the past research, 6) the corrosion rate of the metal with QCM sensors and the corrosive gas concentrations were independently measured. Then corrosion environment was analyzed from the corrosion rate of the measured metal compared with the concentration of the corrosive gas.…”