No matter the type or size of an industrial facility, an undetected buildup of combustible gases can lead to a catastrophic event. Whether in the confined spaces of a manufacturing plant, research lab vent hood, or an isolated offshore drilling platform, combustible gas buildup can lead to disaster.
Because of this, companies have long used Lower Explosive Limit (LEL) gas leak detectors equipped with infrared technology. Infrared sensors are far more stable and reliable than traditional catalytic bead sensors. To gain a better understanding of how and why these sensors are better long term solutions, let’s take a closer look at the risks and rewards associated with infrared LEL meters.
Unlike catalytic bead sensors, infrared sensing elements require intelligent signal processing to generate a stable, linearized output. This means that each infrared sensor contains a dedicated microprocessor that performs multiple operations on the sensing elements signal that include analog-to-digital conversion, temperature compensation, response curve linearization and fault checking. While they are more expensive than simple cat-bead sensors, they are considered very good investments due to their stability over time and reduced need for calibration. As a result, they are far more likely to operate when needed and keep employees and multi-million dollar equipment and facilities safe.
Modern infrared combustible gas sensors can sense methane, propane, butane, methane, benzene, and many more combustible hydrocarbons. However, note the importance of the word ‘hydrocarbon’. Infrared absorption sensors work by detecting a drop in infrared light levels due to the absorption of infrared light by the hydrogen-carbon bonds in combustible hydrocarbons. Combustible gases such as hydrogen that have no H-C bonds cannot be detected and so do require cat-bead sensors. Given this limitation, however, infrared detectors can be placed virtually anywhere in a facility to provide constant monitoring for hazardous conditions.
Infrared combustible gas sensors do not have a ‘detection radius’ but rather respond to the presence of combustible gases in ambient air. To maximize the effectiveness of combustible gas detectors, they should be placed in areas where gases are most likely to be present – around valves or fittings, or next to air return ducts. If lighter-than-air combustible gases are a hazard, placing detectors in or near the ceiling will be beneficial; for heavier-than-air gases such as propane, placing sensors a few feet above the floor is recommended.
Pro Tip: For fence perimeter monitoring, consider using an Open Path combustible gas detection system. While they use the same absorption principle as ambient detectors, they transmit long-range beams of infrared light between a separate transmitter and receiver.
LEL detectors are designed, certified, and tested to withstand the harshest work environments. From an industrial plant that has confined spaces with high humidity levels to an offshore drilling platform where high temperatures, vibration, and other factors may make some detectors unreliable, modern infrared LEL units are the ideal solution. A quality LEL gas detector is a worthwhile investment for any facility with potentially hazardous conditions.