Monitoring simultaneously water-content and corrosion rates in low conductivity natural gas pipeline systems) is carried out using membrane-based electrochemical sensors. An ion conducting membrane improves conductivity in humid natural gas in which electrochemical measurements can be performed. In this study, we monitor corrosion rate and humidity of a gas pipeline through the use of commercial Nafion™ membranes, whose conductivity depends on the partial pressure of water vapor in the gas stream. To improve the accuracy, consistency, and reproducibility of data collection, sensor designs vary between electrode preparation using platinum wires versus nanofabricating flat electrode surfaces and configuration. Data for humidity and corrosion rates within various environments is collected using electrochemical impedance spectroscopy and linear polarization resistance tests. Data for 2-, 3-, and 4-electrode cell tests are presented to compare experimental artefacts among sensor designs.