Flame detector

Patent 4750142 Issued on June 7, 1988. Estimated Expiration Date:

January 27, 2006. 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.

Abstract Claims Description Full Text

Patent References

Two channel optical flame detector
Patent #: 4206454
Issued on: 06/03/1980
Inventor: Schapira , et al.

Optical flame and explosion detection system and method
Patent #: 4220857
Issued on: 09/02/1980
Inventor: Bright

Fire or explosion detection
Patent #: 4423326
Issued on: 12/27/1983
Inventor: Ball

Optical fire or explosion detection system and method Patent #: 4553031
Issued on: 11/12/1985
Inventor: Cholin , et al.

Inventors

Assignee

Hochiki Corporation

Application

No. 06/822892 filed on 01/27/1986

US Classes:

340/578, By radiant energy169/61, Electrical control250/340Methods

Examiners

Primary: Lall, Parshotam S.
Assistant: Juffernbruch, Daniel W.

Attorney, Agent or Firm

Lackenbach, Siegel, Marzullo & Aronson

International Class

G08B 17/12 (20060101)

Foreign Application Priority Data

1985-02-04 JP

Abstract

A flame detector comprising a flame sensor, a storing section for storing a predetermined reference value, a comparing section for comparing a value of a signal from the flame sensor which changes in amplitude corresponding to a change in flickering of flames with said reference value and adapted to detect flames when the value of said signal exceeds the reference value, and a flame determining section which comprises a computing section for computing a ratio of an amplitude value of a minus change component to an amplitude value of a plus change component of changes in flickering of flames. The storing section stores a preset first threshold value and a preset second threshold value higher than said first threshold value, and the flame determining section signifies the presence of flames is when the ratio of the amplitude values of the signals is larger than the first threshold value and lower than the second threshold value.