Dew Point Meter Based on Graphene Oxide Film

Background

Dew point is a value which measures the absolute amount of moisture in the air in a particular space by predicting at what temperature moisture will condense on a surface. It provides an excellent method of controlling humidity because, unlike relative humidity that varies with temperature, dew point values remain constant regardless of temperature. Dewpoint hygrometers are devices that detect the dew point temperature of air by cooling a surface in contact with the air to the dew point temperature. The dew point hygrometer is claimed to be the most accurate instrument for measuring air humidity. There are plenty of control strategies and equipment that can remove moisture from the air, but accurate measurement of the dew point levels is the only effective way to control the amount of moisture in the air. Chilled mirror hygrometers are used in labs as well as in industrial applications where precise and repeatable humidity measurement and control is required. However, these temperamental laboratory grade sensors are very expensive.

Technology

Researchers at Stony Brook University (SBU) have proposed a new method of detecting dew point and icing conditions with hygrometers based on carbon nanomaterials. These sensors conduct the adsorption of a molecular thin layer of water molecules on the surface of graphene oxide and detect the first order phase transition of water to ice. Proton conduction in graphene oxide is found to be associated with the humidity level and temperature variation. Thus, graphene oxide films can be utilized as a new, cost‑effective hygrometer platform with the direct and precise determination of dew point for the replacement of expensive dew point sensors.