Which statement best describes the function of methane detectors on non-explosion-protected plant?

• A. They monitor oxygen levels
• B. They detect GB concentration and trigger a visible alarm at 1% and trip at 2%
• C. They monitor humidity
• D. They monitor temperature

Answer: (B)

Methane detectors are there to measure the amount of methane in the air around non-explosion-protected plant and respond with two safety levels. When methane hits a low threshold (about 1% by volume), the detector triggers a visible alarm to warn people and prompt action. If methane climbs further to a higher threshold (about 2%), it trips the equipment, shutting down the plant to prevent ignition in an explosive atmosphere. This focus on methane concentration, with a warning level and an automatic shutdown level, is what makes the detector function fit for a non-explosion-protected setup. Options that monitor oxygen, humidity, or temperature don’t describe the detector’s purpose here.