Which of the following practices is essential for monitoring gas levels in a mine?

Continuous air quality testing is essential for monitoring gas levels in a mine because it provides real-time data on the concentration of harmful gases such as methane, carbon monoxide, and other toxic substances. This practice ensures that any dangerous levels can be detected immediately, allowing for timely interventions to protect the health and safety of miners working in the environment. Unlike regular maintenance checks or safety protocols, which play roles in overall mine safety and operational efficiency, continuous air quality testing focuses specifically on the air miners breathe, making it a critical practice to prevent potentially life-threatening incidents related to gas exposure. By consistently monitoring gas levels, mining operations can not only comply with safety regulations but also create a safer working environment.