The IRX2 viewing head is recommended for pulverized coal, oil, hydrogen, sulphide and other difficult waste fuel streams where ultraviolet light is absorbed. The IRIS IRX2 employs a new concept in infrared flame detection by utilizing a solid state infrared "two-color" sensor in conjunction with electronic circuitry that takes advantage of the high frequency-flicker characteristics of flames. The "two-color" sensor is composed of a unique "see-through" silicon photovoltaic front element and a lead sulphide photoconductor back element.
The silicon element covers the spectral range from 350 nanometers to 1100 nanometers and the lead sulphide detector covers the range from where the silicon elements begin to roll-off, 1100 nanometers to 3000 nanometers. The signals from both sensors, after amplification, are added or mixed resulting in a very wide spectral range, that covers the entire visual range well into the infrared longer wavelengths. This new flame monitor is especially useful on those difficult applications, such as black liquor recovery units and lime kilns in the pulp and paper industry.