Fire detector with event recordation

• US 6,078,050 A
• Filed: 05/30/1997
• Issued: 06/20/2000
• Est. Priority Date: 03/01/1996
• Status: Expired due to Term

• Current Assignee: Honeywell International Inc.
• Original Assignee: The Fire Sentry Corp. (Honeywell International Inc.)
• Inventors: Castleman, David A.
• Primary Examiner(s): Westin, Edward P.
• Assistant Examiner(s): HANIG, RICHARD E
• Application Number:
  US08/865,695
• Time in Patent Office: 1,117 Days
• Field of Search: 250/339.15, 250/339.14, 250/342, 250/339.05, 340/578
• US Class Current: 250/339.15
• CPC Class Codes: G08B 17/12 Actuation by presence of radiation or particles, e.g. of infrared radiation or of ions
• CPC Class Codes: G08B 25/002 Generating a prealarm to the central station

Abstract

A process and system for flame detection includes a microprocessor-controlled detector with at least three sensors. A wide band infrared sensor is used as the primary detector, with near band and visible band sensors serving to detect false-alarm energy from nonfire sources. Digital signal processing is used to analyze sensed data and discriminate against false alarms. A multistage alarm system can be provided, which is selectively triggered by the microprocessor. Spectral recording and analysis of prefire data is provided for. The detector can be housed in an enclosed, sealed, removable, plastic horsing that may include an integral plastic window lens.

Claims

1. A fire detector, comprising:

at least one energy sensor;

an analog-to-digital converter connected to said at least one energy sensor;

a first memory connected to an output of said analog-to-digital converter, said first memory temporarily storing digitized data from said at least one energy sensor;

a non-volatile random-access memory to which said digitized data from said at least one energy sensor is transferred upon occurrence of a fire event, said non-volatile random-access memory comprising distinct memory portions for storing digitized data from multiple fire events and timestamp information associated with each fire event; and

a backup DC energy source connected to said non-volatile random-access memory.

2. The fire detector of claim 1 wherein said first memory comprises a volatile random-access memory.

3. The fire detector of claim 1 wherein said first memory comprises a circular buffer.

4. The fire detector of claim 1, wherein said digitized data stored in said non-volatile random-access memory includes data from said at least one sensor for a time period preceding the fire event.

5. The fire detector of claim 1, wherein said non-volatile random-access memory comprises a memory portion for storing a fire response parameter for each fire event along with the digitized data from said at least one energy sensor for the fire event.

6. The fire detector of claim 1, wherein said at least one sensor comprises a wide band infrared sensor.

7. The fire detector of claim 6, wherein said at least one sensor further comprises a visible band sensor and a near band infrared sensor.

8. A method of multiple-event fire detection recordation, comprising the steps of:

sensing radiant energy and generating an energy output signal thereby;

converting said energy output signal into digitized data;

temporarily storing said digitized data in a first memory;

transferring said digitized data from the first memory to a non-volatile random-access memory upon the occurrence of each fire event, the digitized data from each fire event being stored in a separate, predefined segment of the non-volatile random-access memory;

storing in said non-volatile random-access memory a date and time indication for each fire event along with the digitized data corresponding to the fire event; and

providing a backup DC energy source to said non-volatile random-access memory.

9. The method of fire detection recordation of claim 8, wherein said step of temporarily storing said digitized data in a first memory comprises the step of storing said digitized data in a volatile random-access memory.

10. The method of fire detection recordation of claim 8, wherein said step of temporarily storing said digitized data in a first memory comprises the step of storing said digitized data in a circular buffer.

11. The method of fire detection recordation of claim 8, wherein said step of transferring said digitized data from the first memory to said non-volatile random-access memory upon the occurrence of each fire event comprises the step of transferring digitized data generated as a result of sensing radiant energy during a time period preceding the fire event.

12. The method of fire detection recordation of claim 8, further comprising the step of storing a fire response parameter for each fire event in the non-volatile random-access memory along with the digitized data from the energy output signal for the fire event.

13. The method of fire detection recordation of claim 8, wherein said step of sensing radiant energy comprises the step of sensing wide band infrared energy.

14. The method of fire detection recordation of claim 13, wherein said step of sensing radiant energy further comprises the step of sensing near band infrared energy and visible energy.

15. A method of fire detection recordation, comprising the steps of:

sensing radiant energy using a plurality of sensors, and generating a plurality of sensor output signals thereby;

converting said sensor output signals into digital sensor data;

temporarily storing said digital sensor data in a volatile, random-access memory;

processing said digital sensor data to detect fire events, said step of processing comprising the steps of measuring blackbody energy output of a radiant energy source and comparing said blackbody energy output against an energy level threshold;

in response to each detected fire event, transferring the digital sensor data from said volatile, random-access memory to a segment of a non-volatile, static random-access memory;

storing in said non-volatile, static random-access memory a date and time indication for each fire event along with the digital sensor data associated with the fire event; and

providing a backup DC energy source to said non-volatile, static random-access memory.

16. The fire detection recordation method of claim 15, further comprising the step of storing in said non-volatile static, random-access memory an alarm response indication for each fire event along with the digital sensor data associated with the fire event.

17. The method of fire detection recordation of claim 16, further comprising the step of transferring the digital sensor data, the date and time indication and the alarm response indication from said non-volatile, static random-access memory over a digital communication link to an external target device.

18. A method of fire event recordation, comprising the steps of:

sensing radiant energy and generating one or more digitized sensor output signals thereby, each digitized sensor output signal comprising a stream of binary data;

temporarily storing said binary data in a memory buffer, said memory buffer comprising volatile memory;

processing said one or more digitized sensor output signals to detect a fire event;

in response to each detected fire event, transferring the binary data from said memory buffer to a predefined segment of a non-volatile, static random-access memory (RAM);

storing in said non-volatile, static RAM a date and time indication for each fire event along with the binary data corresponding to the fire event;

storing in said non-volatile static, RAM an alarm response indication for each fire event along with the binary data corresponding to the fire event;

providing a backup DC energy source to said non-volatile, static RAM; and

transferring the binary data, the date and time indication and the alarm response indication from said non-volatile, static RAM over a digital communication link to an external target device upon request.

19. A self-contained fire detector with multiple event recordation, comprising:

a fire detector housing;

a plurality of energy sensors;

an analog-to-digital converter connected to said energy sensors;

a first memory disposed within said fire detector housing and connected to an output of said analog-to-digital converter, said first memory temporarily storing digitized data from said energy sensors;

a processor disposed within said fire detector housing and connected to said first memory, said processor having access to said stored digitized data for detecting fire events;

a non-volatile random-access memory to which said digitized data from said plurality of energy sensor is transferred upon occurrence of a fire event, said non-volatile random-access memory disposed within said fire detector housing and comprising distinct memory portions for storing digitized data from multiple fire events and for storing date and time information associated with each fire event; and

a backup DC energy source connected to said non-volatile random-access memory and disposed within said fire detector housing.