Disclosed in the present invention is a visual monitoring method for cross-section temperature fields and radiation characteristics of boiler furnaces by combining radiation images and spectra. Image detectors can be directly inserted into observation holes of a boiler to acquire flame image data, so that when the detection system is applied to a power station boiler, extra holes are not required to be drilled, and therefore, there is no risk that the strength of a furnace wall of the boiler is reduced by drilling holes. According to cross-section temperature fields of a furnace measured by the detection system, the state of combustion in the furnace can be accurately judged, which can play an accurate and effective guiding role in boiler combustion control, and reduce the temperature deviation in each combustion area of the boiler so as to keep the boiler running smoothly, thereby improving the combustion efficiency of the boiler.

Various embodiments disclosed herein describe an infrared (IR) imaging system for detecting a gas. The imaging system can include an optical filter that selectively passes light having a wavelength in a range of 1585 nm to 1595 nm while attenuating light at wavelengths above 1600 nm and below 1580 nm. The system can include an optical detector array sensitive to light having a wavelength of 1590 that is positioned rear of the optical filter.

A human presence detection system and a human motion detection system. A detection apparatus that includes a thermal sensor, a lens mounted on the thermal sensor, and a controller are incorporated into the system. The lens is configured to focus thermal radiation incident from a spatial zone or the thermal radiation being radiated by an object onto the thermal sensor for sensing the thermal radiation and outputting a temperature signal. The controller incorporates filters and circuits to process the temperature signal and output digital temperature counts proportional to the thermal radiation from the spatial zone or the object. The detection apparatus can accordingly perform human presence detection or human motion detection by processing fluctuation of the digital temperature counts.