Gas sensors are crucial devices in various fields including industrial safety, environmental monitoring, gas infrastructure and medical diagnosis. These sensors measure specific gases in different environments, guaranteeing operational safety and efficiency through precise on-site measurements. Designed for high sensitivity, stability and reliability, gas sensors must also be cost-effective, quickly responsive and compact. To address these diverse requirements, we have developed two types of gas sensors based on the volumetric and the manometric method. These sensors operate by measuring the gas volume and the pressure changes, respectively, of the emitted gas. These sensors are capable of determining gas transport parameters such as gas uptake, solubility and diffusion coefficient for gas-charged polymers in high pressure environment. The sensors provide rapid responses within one second and can measure gas concentrations ranging from 0.01 wt ppm to 1500 wt ppm with adjustable sensitivity and measurement ranges. Performance evaluations demonstrate the sensors' reliability, adaptability to varying measurement ranges and stability under temperature and pressure fluctuations. As a result, this sensor system facilitates the real time detection and analysis of gas transport properties in pure gases including H₂, He, N₂, O₂ and Ar, making it suitable for pure gas sensing.

The purpose of this study is to investigate concentration and emission coefficients of 22 odorous compounds, which are regulated by the domestic act, emitted from pig buildings by on-site survey. The odorous compounds which were detected in at least one pig building were ammonia, hydrogen sulfide, methyl mercaptan, dimethyl sulfide, dimethyl disulfide, trimethyl amine, stylene, toluene, xylene and methyl ethyl ketone whereas other 12 odorous compounds were not detected in pig buildings. In general, indoor concentrations of odorous compounds in pig buildings were higher in scraper type than slurry type based on pig manure collection system and higher in enclosed type than winch-curtain type based on ventilation mode, respectively. In monthly distribution of odorous compounds, their concentrations in September and October when ventilation rate in pig building decreased relatively were generally higher than those in July and August when ventilation rate in pig building is relatively high. On the contrary, the emission coefficients of odorous compounds in pig building were generally higher in July and August than September and October. The levels of emission coefficients of odorous compounds obtained from this study were similar or slightly higher compared to those reported previously from foreign countries.