A gas sensor is a device that detects the presence of specific gases in the environment. It works by measuring changes in electrical resistance or other properties when gas molecules interact with the sensor material. Common applications include monitoring air quality, detecting leaks in industrial settings, and ensuring safety in confined spaces. These sensors can identify various gases, such as carbon monoxide, methane, and hydrogen sulfide. They are essential in many industries, including oil and gas, chemical manufacturing, and environmental monitoring. By providing real-time data, gas sensors help prevent accidents and protect both human health and the environment.