Flame sensor system

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Reuter Stokes, a Baker-Hughes business, has introduced the new FT Lite flame sensor system, developed for high-temperature industrial burner applications. The new product is designed for applications with operating temperatures up to 120°C. This makes the FT Lite sensor ideal for use in utility boilers, cement kilns, and recovery boilers. These environments are often too harsh for standard sensors to operate reliably, because they typically cannot withstand temperatures higher than 80°C.

The sensor system has models that hold North American, ATEX, and IECEx certifications for operation in hazardous areas. For power generation applications, a Class I, Division 2 and Zone 2 FT Lite sensor is available. For the oil and gas industry, Reuter-Stokes offers a version of the sensor that is Class I, Division 1 and Zone 1 certified.

The FT Lite sensor is engineered to achieve maximum efficiency and effectiveness. The 4-20 mA output is powered by 24 VDC, without the need for additional amplifiers. Designed specifically for harsh burner environments, the FT Lite sensor’s 15-foot interconnect cable features a rugged MIL-SPEC connector and can withstand temperatures up to 250°C.


For burner management system applications that require backward compatibility to relay inputs, Reuter-Stokes offers a new, pre-configured DIN rail-mounted relay module that easily converts the FT Lite sensor’s output. The relay module is suitable for Zone 2 hazardous environments.

The system’s operation is simple and direct: When the current input from the sensor exceeds 6 mA, the output of the relay module closes, indicating that the flame is on. When the current drops below 5 mA, the relay opens, indicating the flame is off. Because the relay is normally open, if the module loses power, the open relay will indicate a flame-off scenario.