System for verifying detection of a fire event condition

• US 20030174056A1
• Filed: 03/12/2002
• Published: 09/18/2003
• Est. Priority Date: 03/12/2002
• Status: Active Grant

• Current Assignee: Lynch & Reynolds, P.C.
• Original Assignee: Lynch & Reynolds, P.C.
• Inventors: Harshaw, Bob F.
• Granted Patent: US 6,788,198 B2
• Time in Patent Office: Days
• US Class Current: 340/522
• CPC Class Codes: G08B 17/00 Fire alarms; Alarms responsive to explosion
• CPC Class Codes: G08B 29/188 Data fusion; cooperative systems, e.g. voting among different detectors
• CPC Class Codes: G08B 29/26 by updating and storing reference thresholds

Abstract

A system for verifying the detection of a fire event by a fire detection device utilizing multiple air condition sensors includes a programmable logic circuit that evaluates whether input data supplied thereto by the sensors satisfies predetermined threshold parameters. If the input data matches one particular parameter, the other threshold parameters are decreased and evaluation frequency is increased. The circuit energizes an alarm if input data from the sensors satisfies the particular parameter and at least one of the decreased parameters or if the input data satisfies at least two non-decreased parameters. Therefore, a fire event sensed by one sensor is verified by another sensor before causing an alarm. At power-up, the circuit compares initial input data with the predetermined parameters and modifies the parameters if the input data is within respective predetermined ranges. This also decreases false alarms.

Claims

1. A system for verifying the detection of a fire event condition for use with a fire detection device having multiple air condition sensors, said system comprising:

an alarm;

a programmable logic circuit capable of evaluating input data supplied thereto by the air condition sensors indicative of respective ambient air conditions, said logic circuit including means for generating an output signal to energize said alarm;

wherein said logic circuit includes a plurality of predetermined threshold parameters corresponding to ambient air conditions indicative of respective fire event conditions;

a power source electrically connected to said alarm and said logic circuit; and

wherein said logic circuit includes means for comparing said input data to respective threshold parameters, said logic circuit decreasing said threshold parameters other than a particular threshold parameter when said input data is at an undesirable relationship with respect to said particular threshold parameter.

2. The system as in claim 1 wherein said logic circuit is capable of generating said output signal for energizing said alarm if said input data is at an undesirable relationship with at least two of said threshold parameters.

3. The system as in claim 1 wherein said logic circuit is capable of generating said output signal for energizing said alarm if said input data is at an undesirable relationship with said particular threshold parameter and at least one of said decreased threshold parameters.

4. The system as in claim 1 further comprising means in said circuit for resetting said decreased threshold parameters upon expiration of a predetermined time after decreasing said threshold parameters.

5. The system as in claim 1 further comprising means in said circuit for evaluating said input data at more frequent time intervals when said threshold parameters have been decreased.

6. The system as in claim 1 further comprising means in said circuit for requesting at power-up initial input data from the air condition sensors, said circuit including means for comparing said initial input data with respective threshold parameters, said circuit modifying said respective threshold parameters if said initial input data is at a predetermined relationship with said respective threshold parameters.

7. The system as in claim 6 wherein said predetermined relationship with regard to said initial input data and said respective threshold parameters includes a measured air condition that is within a predetermined range relative to a corresponding threshold parameter.

8. The system as in claim 1 wherein said power source is a battery.

9. A method for verifying the accuracy of detection of a fire event condition by a fire detection device utilizing multiple air condition sensors, said method comprising:

providing an alarm;

providing a programmable logic circuit;

providing a power source for said alarm and programmable logic circuit;

demanding from the air condition sensors in the fire detection device input data indicative of respective ambient air conditions;

providing said input data to said logic circuit for comparison with a plurality of predetermined threshold parameters;

if said input data is at an undesirable relationship with a particular threshold parameter, decreasing said threshold parameters other than said particular threshold parameter; and

energizing said alarm if said input data is at an undesirable relationship with said particular threshold parameter and at least one of said decreased threshold parameters.

10. The method as in claim 9 further comprising energizing said alarm if said input data is at an undesirable relationship with at least two threshold parameters.

11. The method as in claim 9 further comprising resetting said decreased threshold parameters upon expiration of a predetermined time after decreasing said threshold parameters.

12. The method as in claim 9 further comprising demanding said input data at more frequent time intervals after decreasing said threshold parameters.

13. The method as in claim 9 further comprising:

demanding at initial power-up from the air condition sensors in the fire detection device initial input data indicative of respective ambient air conditions;

providing said initial input data to said logic circuit for comparison with respective threshold parameters; and

if said initial input data is at a predetermined relationship with said respective threshold parameters, utilizing said logic circuit to modify said respective threshold parameters.

14. The method as in claim 13 wherein said predetermined relationship includes a measured air condition that is within a predetermined range relative to a corresponding threshold parameter.

15. A method for verifying and improving the accuracy of detection of a fire event by a fire detection device utilizing multiple air condition sensors, said method comprising:

providing an alarm;

providing a programmable logic circuit;

providing a power source for said alarm and programmable logic circuit;

demanding at initial power-up from the air condition sensors in the fire detection device initial input data indicative of respective ambient air conditions;

providing said initial input data to said logic circuit for comparison with a plurality of predetermined threshold parameters; and

if said initial input data is at a predetermined relationship with regard to said respective threshold parameters, utilizing said logic circuit to modify said respective threshold parameters.

16. The method as in claim 15 further comprising:

demanding from the air condition sensors input data indicative of respective ambient air conditions;

providing said input data to said logic circuit for comparison with said threshold parameters;

if said input data is at an undesirable relationship with a particular threshold parameter, decreasing said threshold parameters other than said particular threshold parameter; and

generating a signal in said logic circuit if said input data is at an undesirable relationship with said particular threshold parameter and at least one of said decreased threshold parameters, said signal energizing said alarm.

17. The method as in claim 16 further comprising generating another signal if said input data is at an undesirable relationship with at least two threshold parameters, said another signal energizing said alarm.

18. The method as in claim 15 further comprising generating a signal if said input data is at an undesirable relationship with at least two threshold parameters, said signal energizing said alarm.

19. The method as in claim 16 further comprising resetting said decreased threshold parameters upon expiration of a predetermined time after decreasing said threshold parameters.

20. The method as in claim 19 further comprising demanding said input data at more frequent time intervals after decreasing said threshold parameters.