| 摘要 |
<p>To detect flames burning carbon-free hydrogen-bearing fuels, first, second, and third sensors sense first, second and third regions of an infrared water emission band, and generate first, second, and third signals. A processor generates an alarm when the sensors indicate flame. The first region low cut-off wavelength may be lower than the second region low cut-off wavelength. The third region high cut-off wavelength may be higher than the second region high cut-off wavelength. The combined regions may include nearly the entire water emission band. The processor may discriminate distances to flames using the sensor signals. A fourth sensor may sense moisture concentration, and the processor may discriminate distances based thereon. The regions may be defined such that for a fire, all three regions receive substantial energy, with second region to first region energy ratio less than 1:1 and a second region to third region energy ratio less than 1:1.</p> |
