What is an automatic methane detector?

• A. A detector that measures humidity
• B. A methane detector that automatically activates a visible alarm and trips the electricity supply when methane concentration reaches a particular level.
• C. A detector that sounds alarm only manually
• D. A device that filters methane

Answer: (B)

An automatic methane detector is a device that continuously monitors methane in the mine air and, once a preset concentration is reached, automatically triggers a visible alarm and trips the electrical supply. This automatic action is crucial because methane buildup can become explosive, and relying on someone noticing the gas level and manually sounding an alarm could be too slow. The detector is linked to the mine’s safety systems to provide immediate warning to people and to cut power to equipment to reduce ignition risk. The other options miss the automatic detection and control functions: humidity monitors measure moisture, a manual alarm requires human action, and a device that filters methane does not detect gas or automatically intervene.