Gas Sensors Based on Volumetric Analysis and Manometric Analysis for Measuring Gas Uptake and Diffusivity in Gas Charged Nitrile Butadiene Rubber

Gas sensors play a crucial role by monitoring hazardous gas concentrations and air quality in real-time, thus preventing accidents, protecting health and ensuring environmental and industrial safety. They are also essential in various applications for improving energy efficiency and environmental protection. With the increasing demand for hydrogen refueling stations and hydrogen fuel cell vehicles in the active hydrogen economy, the need for precise sensing technology to detect hydrogen concentration is critical given hydrogen's broad explosion range. To ensure safety and efficiency, the gas sensors must accurately detect various gas concentrations in real-world environments. To meet these requirements, we propose gas sensors that are not only highly sensitive and stable but also cost-effective, fast-responding, and compact. This study presents two types of gas sensors based on the principles of volume analysis and pressure analysis. These sensors can measure gas charge quantities, solubility, diffusivity, and leakage rates of hydrogen, helium, nitrogen, and argon gases charged in nitrile butadiene rubber under high-pressure conditions. Performance evaluation results showed that the two sensors have a stability of 0.2 %, a resolution within 0.12 wt·ppm, and can measure gas concentrations from 0.1 wt·ppm to 1400 wt·ppm within one second. Additionally, the sensitivity, resolution, and measurement range of the gas sensors are adjustable. The measurement results of the four gases’ charge quantities and diffusivities obtained from both sensors are consistent within the uncertainty range. This system possesses the capability to detect and characterize gases in real-time, making it applicable to hydrogen infrastructure facilities and to help realize a safe hydrogen society in the future.