Method and detector for detecting a flame
Patent 5594421 Issued on January 14, 1997. Estimated Expiration Date: 
December 19, 2015. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
December 19, 2015. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3739365 Two channel optical flame detector Flame detector High temperature resistant flame detector System for detecting random events Patent #: 5434560 InventorApplicationNo. 574773 filed on 12/19/1995US Classes:340/578, By radiant energy250/554, Flame light source340/577FlameExaminersPrimary: Hofsass, JefferyAssistant: La, Anh Attorney, Agent or FirmForeign Patent References
International ClassG08B 017/12Foreign Application Priority Data1994-12-19 EPAbstractA flame is detected by signal analysis for intensity variations in radiation received by a sensor. A low-frequency spectrum of the signal is analyzed for mid- and cut-off frequencies, and the signal is classified as periodic or non-periodic. Periodic signals with a mid-frequency (ωmp) above a first frequency value (G1), and non-periodic signals with a cut-off frequency (ωgc) above a second frequency value (G2) are classified as interfering signals. The first frequency value is determined by the flicker frequency of a stationary flame having a magnitude corresponding to a flame of minimum magnitude to be detected. The second frequency value is selected greater than the first frequency value (G1). | |
