What zones are considered relevant zones (ERZ) for methane detector placement?

• A. ERZ0 and ERZ1
• B. ERZ2
• C. ERZ3
• D. ERZ4

Answer: (A)

The main idea here is that detector placement should cover the areas where methane is most likely to appear and be detected in time to warn and trigger ventilation responses. In this framework, the zones closest to the primary airflow paths and potential methane sources are the ones that matter most, which are ERZ0 and ERZ1. Placing detectors in ERZ0 and ERZ1 provides early warning across the areas where methane could first enter the active ventilation circuit, giving workers and control systems a chance to react before concentrations rise in other parts of the mine. The other zones (ERZ2, ERZ3, ERZ4) are positioned further back or in areas where detection would not significantly improve safety or is addressed by other monitoring strategies, so they’re not considered the relevant zones for methane detector placement.