Explosive gases can be detected using which meters?

• A. GPS meters
• B. LEL meters
• C. Thermal meters
• D. Pressure meters

Answer: (B)

LEL meters, or Lower Explosive Limit meters, are specifically designed to measure the concentration of combustible gases in the air. They provide critical safety information by indicating whether the level of a gas is approaching an explosive concentration. When the concentration of a gas reaches its lower explosive limit, it may ignite if an ignition source is present, posing a significant risk in environments such as wastewater treatment facilities.

These meters work by detecting gas concentrations in a percentage of the volume of air and are calibrated to identify a range of gases, allowing operators to monitor and manage potential hazards effectively. In the context of wastewater treatment, this monitoring is crucial because many organic materials can generate methane and other dangerous gases during decomposition.

The other options listed do not serve this specific purpose. GPS meters are used for location tracking, thermal meters measure temperature, and pressure meters gauge pressure levels, none of which are suitable for detecting explosive gases. Therefore, LEL meters are the appropriate choice for monitoring hazardous gas levels in wastewater treatment and other industrial settings.