A variety of bottled gases are certified for resale as "calibration gases ", specifying the concentration of contaminants in each bottle. Often the water content is specified, and this must be monitored with precision both by the supplier and consumer.
A reliable supply of breathing air is critical for applications in the military, medical and fire fighting sectors. The presence of excess moisture in breathing air can lead to freezing in the pressure regulator and ice blocking the orifice, causing an interruption to the supply of air to the user. Such freezing effects have caused the loss of life and equipment in submarines and aircraft.
Foil-wrapped foods are often sealed with air, or an inert gas. It is possible to extend the storage life of the food if the air trapped between the foil and the food is replaced with nitrogen of very low moisture content .
Hydrogen is used to cool large, stationary generators because of its high heat capacity and low viscosity, and must be kept dry to maintain both of these properties. Ambient moisture is considered a contaminant, which will reduce the heat capacity and increase the viscosity of the cooling hydrogen.
The presence of humidity in a blanketing gas for sensitive instruments can cause corrosion problems, rapid changes incalibration and loss of sensitivity. The presence of oil contamination in compressors can cause similar problems.
The presence of moisture in high-pressure natural gas from production wells causes pipelines and associated valves to freeze. High moisture content also leads to the formation of hydrates of the liquid hydrocarbons present, thus causing further difficulties. The moisture content
The Advanced Gas Cooled Reactor uses carbon dioxide gas to transfer heat from the nuclear fission core to the water boiler for steam generation. The moisture content needs to be monitored to avoid corrosion damage, and continuous moisture monitoring acts as a boiler leak detector or bulk moisture met...
Optimal performance of petrochemical reforming catalysts depends upon maintaining an optimal moisture / chloride ratio within the reforming reactor. When moisture and chloride are out of balance, catalysts suffer from higher deactivati...
Moisture is continuously monitored in the vacuum evacuation and gas refill of oil-filled transformers. The moisture content of blanketing gases used in the transformers directly affects the dielectric properties of the oil, through water vapour dissolution.
Excess humidity in the air used to dry plastic pellets has several adverse effects on the quality of the products produced. The strength of the product is decreased. The surface of the product can be blemished. The product can have a ‘cloudy’ appearance.
Moisture needs to be measured in feed stock gases in the manufacture of polymers . For example, pre-dried benzene is fed in to a reactor containing hydrochloric acid – if the dryers are not operating properly moisture in the benzene promotes acid corrosion of the reactor and process lines. Several processes require water concentrations of specific values to optimise efficiency and yield; in such cases more sophisticated instruments are required.
Manufacturers of bandages and permeable membranes must comply with tests to determine the extent of permeability of the finished product. Quality can be improved and wastage reduced if the moisture can be measured quickly and reliably.
SF6 (sulphur hexafluoride ) or air is used as an insulation gas in circuit breakers . Excess moisture in these gases causes arcing, which can trip the circuit breaker and cut off power to the distribution network. More seriously, such arcing can lead to physical damage of equipment and, on occasion, death of plant operatives (please ask for our case study on circuit breakers).