| 摘要 |
<p>The presence of a burner flame, in a multiple burner installation, is monitored by sensing a signal indicative of the spectrum of the fluctuating component in the radiation of the flame over a range of frequencies. In the lower frequency range a measure (D1,D2) is obtained of the difference of signal strength at two predetermined frequency levels (L,LL). The signal strength is also measured at a higher frequency (H). At the higher frequency there is a significant difference in signal intensity between the flame-on and flame-off conditions, while the change of signal strength between the spectra of flame-on and flame-off conditions in the lower frequency range is sensitive to frequency. By processing the two measures together they can augment each other and produce an enhanced change of signal between flame-on and flame-off conditions, making detection easier. <IMAGE></p> |
