• LEL monitoring in ATEX environments


LEL monitoring in ATEX environments

Dec 13 2022

The goal of LEL monitoring is to detect combustible gases and trigger corresponding safety measures before they can reach dangerous concentrations. Special Ex protection requirements apply to any devices used for monitoring combustible gases and vapors in ATEX zones.

Fixed gas detection systems increase your safety

Potentially explosive areas (ATEX or Ex zones) can occur throughout many industries, as combustible gases are either created by or used in their applications. Dangers arise when both an ignitable compound made of combustible gas and air and an ignition source are present. To minimize this risk, Ex zones are permanently monitored for combustible gases and vapors up to the lower explosion limit (% LEL). Transmitters using the catalytic combustion principle have already been proven to work well in these situations, but other suitable sensor technologies, such as infrared or semiconductors, are also reliable.

Danger assessment of Ex zones

Depending on the probability of a potentially explosive atmosphere occurring, areas are classified either as Ex zone 2 (explosive atmosphere not likely to occur), Ex zone 1 (explosive atmosphere likely to occur) or Ex zone 0 (explosive atmosphere present continuously or frequently). It is crucial that the gas detector you are using is approved for use in the correct Ex zone.

Cost-efficient solution for Ex zone 2

The CC22 ex transmitter is approved for Ex zone 2. It uses catalytic combustion to monitor combustible gases and vapors, such as acetone, propane or methane, and digitally transmits the measured values to a controller. The transmitter was designed to be especially easy to service. It can be configured and calibrated comfortably via a mobile phone and the GfG app. If the CC22 ex has been mounted in a hard to reach location, the test gas application can be carried out by remote calibration without affecting the stack effect of the sensor housing, which ensures short response times.

Safe LEL monitoring

The CC28 is a reliable transmitter equipped with a catalytic combustion sensor for Ex zone 1. It communicates using industry standard 4-20mA signal transmission. The smart sensor technology and the optional RC2 remote control allow for quick sensor replacements and straightforward maintenance, even if the transmitter has been installed near the ceiling. The CC28 with its SIL-certified hardware (SIL 3 in redundant operation), can also be used in applications that call for functional safety (Safety Integrity Level or “SIL”).

Ex protection on the highest level

Only gas detection systems with a limited supply voltage may be used in the most dangerous zones. The intrinsically safe IR29 i transmitter is a safe solution for monitoring combustible gases in Ex zone 0 when used in combination with a safety barrier, such as the SB1. The IR29 i uses the non-dispersive infrared measuring method. The infrared sensors used for this are very durable and resistant to sensor poisons (such as silicone vapors) and are able to detect combustible gases even in oxygen-free environments. Due to its sturdy design and stainless-steel housing as well as its high protection class (IP67) and options for pressure, humidity and temperature sensor technology which compensate for environmental influences, the IR29 will work reliably, even in harsh conditions. Its integrated self-checks further increase the level of safety.

GfG offers suitable transmitters for every Ex zone and a variety of combustible gases and vapors. Contact us for a free consultation and let us support you in planning your gas detection system.

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