Tracer gas is used in scientific research as a way to track the movement or dispersion of gases in different environments. This technique involves releasing a small amount of an inert gas, such as helium or sulfur hexafluoride, into the environment and then using specialized equipment to detect and measure its concentration at various locations. Tracer gas studies are commonly used in atmospheric research to study air pollution, atmospheric dispersion, and airflow patterns. They can also be used in indoor environments to study ventilation systems, air quality, and the spread of contaminants. Overall, tracer gas research is a valuable tool for understanding the behavior of gases in different environments and can provide important insights into environmental and health-related issues.