Characterization of low-cost methane sensors for outdoor use

Abstract

Methane is known as a major greenhouse gas and there are not many economical ways of measuring smaller methane concentrations. Currently, small concentration methane sensing technology is expensive and difficult to apply on a large scale. A lack of inexpensive methane-sensing technologies leaves many small leaks in various machines undetectable. BPX Energy (Denver, CO) partnered with the Colorado Fuel Cell Center at Colorado School of Mines to characterize inexpensive, linearly applicable methane sensors for greenhouse gas detection. In this effort, the team at the Colorado Fuel Cell Center has created a testing apparatus featuring an environmental chamber to quantify sensor response over a range of known methane concentrations, operating temperatures, and humidities. Gas composition is regulated using mass flow controllers. Chamber temperature and humidity are measured by an Arduino interfacing with additional data acquisition hardware. Sensor response is measured using National Instrument's PCI analog-to-digital tools. The control and data collection are fully controlled by a LabView script designed to execute scripted tests. The research includes extensive data collection, curve fitting and analysis. In addition to characterizing sensor response to changes in humidity and temperature, the large set of sensors examined provides insight to the consistency of sensor outputs, and precision between sensors.