Alarm condition detecting method and apparatus
First Claim
1. A method for detecting an alarm condition comprising repeatedly converting an ambient condition into voltage outputs, repeatedly converting the voltage outputs into a series of actual analog values, repeatedly calculating an average analog value from the series of actual analog values, repeatedly calculating a difference between said average analog value and the last actual analog value of the series of actual analog values, repeatedly comparing said difference with a predetermined delta-threshold value, and indicating an alarm condition when the difference between the average analog value and the last actual analog value exceeds the delta-threshold value.
2 Assignments
0 Petitions
Accused Products
Abstract
Methods for detecting an alarm condition includes repeatedly converting an ambient condition into voltage outputs in detector apparatus repeatedly converting the voltage outputs into a series of actual analog values, polling the series of actual analog values to determine an average analog value, repeatedly comparing the difference between the average analog value and the last actual analog value with a predetermined delta-threshold value and indicating an alarm condition when the difference between the average analog value and the last actual analog value exceeds the delta-threshold value. Methods for detecting an alarm condition further includes repeatedly comparing the average analog value with a maintenance threshold value and indicating a maintenance signal when the average analog value exceeds the maintenance threshold value.
-
Citations
29 Claims
- 1. A method for detecting an alarm condition comprising repeatedly converting an ambient condition into voltage outputs, repeatedly converting the voltage outputs into a series of actual analog values, repeatedly calculating an average analog value from the series of actual analog values, repeatedly calculating a difference between said average analog value and the last actual analog value of the series of actual analog values, repeatedly comparing said difference with a predetermined delta-threshold value, and indicating an alarm condition when the difference between the average analog value and the last actual analog value exceeds the delta-threshold value.
-
12. A method for detecting an alarm condition comprising:
-
repeatedly converting an ambient condition in a predetermined location into voltage outputs, repeatedly converting the voltage outputs into a series of actual analog values, repeatedly comparing the last actual analog value of the series of actual analog values to a predetermined pre-alarm threshold value and generating a first status code if the last actual analog value does not exceed the pre-alarm threshold value and a second status code if the last actual analog value exceeds the pre-alarm threshold value, calculating an average analog value from the series of actual analog values when the second status code is generated, repeatedly calculating a difference between said average analog value and the last actual analog value, repeatedly comparing said difference with a predetermined delta-threshold value, and indicating an alarm condition when the difference between the average analog value and the last actual analog value exceeds the delta-threshold value. - View Dependent Claims (13, 14, 15, 16, 17, 18)
-
- 19. A method for maintaining substantially constant sensitivity in an alarm detection system where sensitivity is a difference between an analog value representative of an ambient condition and an alarm threshold value, comprising the step of determining said analog value and setting an alarm threshold value by adding a predetermined delta-threshold value to the analog value.
- 25. A method for detecting an alarm condition comprising repeatedly converting an ambient condition detected at a predetermined location into a series of actual analog values, repeatedly calculating an average analog value from the series of actual analog values, repeatedly determining a threshold value based on the average analog value, repeatedly comparing the last actual analog value of the series of actual analog values with the threshold value, and indicating an alarm condition when the last actual analog value exceeds the threshold value.
-
27. A fire alarm system comprising:
-
detector means for converting an ambient condition into a series of actual analog values; data calculation means for averaging the series of actual analog values, for determining an alarm threshold value based on the average analog value, and for comparing the last actual analog value of the series of actual analog values with the alarm threshold value; means for communicating the series of actual analog values to the data calculating means; and means for indicating an alarm condition when the last actual analog value exceeds the alarm threshold value. - View Dependent Claims (28, 29)
-
Specification