Which statement is true regarding methane detectors on underground equipment?

• A. If a fixed detector fails and another remains operational, the machine must not automatically shutdown
• B. If a fixed detector fails and another remains operational, the machine need not automatically shutdown
• C. A failing detector requires immediate evacuation
• D. All detectors must be replaced immediately regardless of status

Answer: (B)

Methane detection on underground equipment relies on redundancy. When there are multiple fixed detectors on a piece of equipment, one detector can fail without forcing an immediate shutdown, as long as another detector remains operational to monitor methane levels. This design helps avoid unnecessary stoppages while still keeping safety coverage intact. The key action is to address the failed detector promptly—arrange repair or replacement according to procedures—while continuing to use the equipment if the remaining detector(s) are functioning properly. Evacuation is not required just because one detector fails, and replacing all detectors immediately regardless of status isn’t necessary. The system’s safety relies on the continued operation of any functioning detector and timely maintenance of the failed one.