Determination of water vapor content and hydrocarbon dew point in natural gas
Bernard Murphy · OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information) · 1984
This paper discusses the principles of moisture analysis, and covers basic concepts, definitions and units followed by a description of the commonly used instrumental methods including their strengths and weaknesses. The effect of absolute pressure on the humidity measurement is reviewed. With analyzers that measure system dew point, the measurement will vary as the gas mixture is subjected to changes in pressure. Dalton's Law indicates that the partial pressure of water vapor will change in the same ratio as total pressure. This results in a direct change in dew point for any change in total pressure. The author emphasizes the importance of knowing both the process pressure and the pressure in the sensor for a complete evaluation of the measurement.