What action must be taken when a fixed methane detector malfunctions?

When a fixed methane detector malfunctions, the correct action is to ensure that equipment must be shut down automatically. This is crucial because methane detection is vital for maintaining safety in mining operations. A malfunctioning detector poses a significant risk, as it could lead to undetected accumulation of methane gas, which is highly flammable and can be explosive. An automatic shutdown prevents potential hazards by ceasing operations until the issue is resolved.

The rationale behind the need for an automatic shutdown is rooted in safety protocols designed to protect both workers and equipment in potentially hazardous environments. The consequences of allowing operations to continue with a non-functional detector could lead to catastrophic events, making the automatic response a necessary safeguard.

In contrast to this correct response, the need for immediate repair, while important in the long run, does not address the immediate safety risk posed by a malfunctioning detector. Ignoring a visible alarm directly contradicts safety practices, as alarms are designed to indicate specific safety concerns. Lastly, while manual monitoring can substitute for automatic systems, it lacks the immediacy and reliability of an automatic shutdown, which is why an automatic response to a detector malfunction is the best practice in this context.