A high-pressure in-situ permeation measuring system was developed to evaluate hydrogen permeation properties of polymer sealing materials under hydrogen environments up to 100 MPa. This system could perform real-time monitoring of hydrogen permeation following high-pressure hydrogen injection, employing the volumetric method for quantitative measurement. By utilizing a self-developed permeation-diffusion analysis program, this system enabled precise evaluation of permeation properties, including permeability, diffusivity and solubility. To apply the developed system to high-pressure hydrogen permeation tests, hydrogen permeation properties of ethylene propylene diene monomer (EPDM) materials containing silica fillers, specifically designed for use in high-pressure hydrogen environments, were evaluated. Permeation measurements were conducted under pressure conditions ranging from 5 to 90 MPa. Results showed that as pressure increased, hydrogen permeability and diffusivity decreased while solubility remained constant regardless of pressure. Finally, the reliability of this system was confirmed through uncertainty analysis of permeation measurements, with all results falling within an uncertainty of 10.8%.

Hydrogen gas sensors are essential for industrial safety, environmental monitoring, and the energy sector. As hydrogen infrastructure expands and hydrogen fuel cell vehicles become more widespread, precise detection of hydrogen, which has a wide explosive range, has become increasingly critical. To ensure accurate detection of hydrogen in real-world conditions, sensor technologies must offer high sensitivity, stability, and reproducibility, along with cost-effectiveness, fast response time, and compact design. This study introduces a hydrogen gas sensor based on pressure analysis principles. This sensor was developed to quantitatively evaluate hydrogen uptake, diffusion behavior, solubility, and release characteristics in polymers under high-pressure conditions. Experimental results demonstrated the sensor’s excellent performance, with a stability of 0.2%, a resolution of 0.12 wt·ppm, and a measurement range of 0.12 to 1500 wt·ppm, all within 1 second. Furthermore, the sensor's sensitivity, resolution, and detection range could be tuned to suit different operational environments. Uncertainty analysis showed an expanded uncertainty of 8.8%, confirming the system’s capability for real-time hydrogen detection and characterization. This sensor technology is well-suited for applications in hydrogen refueling stations and fuel cell systems, contributing to the advancement of a safe hydrogen society.

Gas sensors are crucial devices in various fields such as industrial safety, environmental monitoring, and gas infrastructure. Designed to have high-sensitivity, stability, and reliability, gas sensors are often required to be cost-effective with quick response and compactness. To meet diverse needs, we developed two types of gas sensors based on volumetric and manometric analyses. These sensors could operate by measuring gas volume and pressure changes, respectively, based on emitted gas. These sensors are capable of determining gas transport parameters such as gas uptake, solubility, and diffusivity for gas-charged polymers in a high-pressure environment. These sensors can provide rapid responses within one-second. They can measure gas concentration ranging from 0.01 wt·ppm to 1,500 wt·ppm with adjustable sensitivity and measurement ranges. As a result, such sensor system can be used to facilitate real time detection and analysis of gas transport properties in pure gases including H₂, He, N₂, O₂, and Ar.