The methodology to monitor gaseous contamination in data centers

In recent years, the data center reliability is paid more attention due to in cloud computing application. In general, the longer term reliability requirement is concerned for it than in general products when in service life. With the more and more severe environmental pollution, the air quality will also directly or indirectly influence the life of data center wherever indoor and outdoor. The air pollution usually has many sources, such as automotive emissions, heavy industrial emissions, volcanoes, landfill sites and so on. Various air pollutant rich in oxide, chloride and sulfur can potentially cause electrical function failure due to corrosion phenomenon on electronic equipment. Therefore, it is necessary to find effective methodology to detect the air quality to extend the life of the data center, as well as the reliability qualification method for material selection. Currently, there are 3 kinds of popular methods to simulate the contaminated air atmosphere in the industry. They are MFG (Mixing Flowing Gas), FoS (Flower of Sulfur) and Clay. MFG is a precise method able to combine various gases in the chamber for real environmental simulation while FoS and Clay method only take sulfur containing gas into account. It will be reviewed their application and advantage in this paper. In addition, Coulometric reduction is a cathodic reduction method and primarily designed to determine the relative buildup of corrosion and tarnish films on metal surfaces by the constant-current coulometric technique. It will be adopted to measure corrosive film thickness with the copper and silver coupons after exposing the metal coupon in the corrosive gas at period of time until thirty days under controlled humidity. In general, the major corrosive products are copper oxide (CuO and Cu₂O), copper sulfur (Cu₂S), silver chloride (AgCl) and silver sulfur (AgS) and can be classified by ISA-S71.04 standard and 2011 ASHRAE data centers guidelines for their severity - evels. In the paper, it will be reviewed the corrosive reaction rate of Cu and Ag with S to be referenced for product design when selecting relevant materials.