Threshold compensation and calibration in distributed environmental detection system for fire detection and suppression
First Claim
1. A system for detecting the environmental status of a monitored space comprising:
- at least one environmental status detector in the monitored space including means for sensing an environmental condition parameter and for producing a detection signal representative thereof, said detection signal being subject to signal drift, said detector further including activatable simulation means for selectively creating a condition simulating an environmental condition parameter of predetermined magnitude and in response for producing a test signal representative thereof; and
signal processing means operably coupled with said detector for sending signals thereto, for receiving and processing signals therefrom, and for determining the occurrence of a predetermined environmental condition in the monitored space as a function of said detection signal and selectively alterable threshold data, said signal processing means including memory means for selective storage of data, and including calibration means for automatically calibrating said system at a predetermined time, said calibration means including--means for prompting storage of data in said memory means representative of said detection signal at said predetermined time as calibration data, such being representative of the environmental status of the monitored space at said predetermined time,means for selectively activating said simulation means in order for said detector to produce said test signal in response,means for prompting storage of test data representative of said test signal, andmeans for determining said threshold data as a function of said calibration and test data and for prompting storage of said threshold data in said memory means for subsequent use in determining said environmental condition.
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Accused Products
Abstract
An environmental detection system particularly useful for fire detection and suppression is provided which ensures high reliability in operation and high reliability in preventing false operation. The preferred system includes a microprocessor-based, software-governed, control panel connected to one or more detector loops. Each loop includes a plurality of parallel-coupled, addressable detectors which send analog signals to the control panel representative of an environmental parameter such as smoke obscuration along with reference and identification signals. The preferred system provides automatic calibration and test of the detectors, automatic testing under load of the backup batteries, flexibility in defining the protective scheme, and storage of history information concerning system alarms and troubles. The preferred system also verifies alarm conditions before actuating an alarm or discharging a fire suppressant.
113 Citations
25 Claims
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1. A system for detecting the environmental status of a monitored space comprising:
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at least one environmental status detector in the monitored space including means for sensing an environmental condition parameter and for producing a detection signal representative thereof, said detection signal being subject to signal drift, said detector further including activatable simulation means for selectively creating a condition simulating an environmental condition parameter of predetermined magnitude and in response for producing a test signal representative thereof; and signal processing means operably coupled with said detector for sending signals thereto, for receiving and processing signals therefrom, and for determining the occurrence of a predetermined environmental condition in the monitored space as a function of said detection signal and selectively alterable threshold data, said signal processing means including memory means for selective storage of data, and including calibration means for automatically calibrating said system at a predetermined time, said calibration means including-- means for prompting storage of data in said memory means representative of said detection signal at said predetermined time as calibration data, such being representative of the environmental status of the monitored space at said predetermined time, means for selectively activating said simulation means in order for said detector to produce said test signal in response, means for prompting storage of test data representative of said test signal, and means for determining said threshold data as a function of said calibration and test data and for prompting storage of said threshold data in said memory means for subsequent use in determining said environmental condition. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A method of detecting the environmental status of a monitored space, said method comprising the steps of;
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providing an environmental status detection system including-- at least one environmental status detector in the monitored space including means for sensing an environmental condition parameter and for producing a detection signal representative thereof, said detection signal being subject to signal drift, said detector further including activatable simulation means for selectively creating a condition simulating an environmental condition parameter of predetermined magnitude and in response for producing a test signal representative thereof, and signal processing means operably coupled with said detector for sending signals thereto, for receiving and processing signals therefrom, and for determining the occurrence of a predetermined environmental condition in the monitored space as a function of said detection signal and selectively alterable threshold data, said signal processing means including memory means for selective storage of data; and automatically calibrating said system at a predetermined time, said calibrating step including the steps of-- storing data in said memory means representative of said detection signal at said predetermined time as calibration data, such being representative of the environmental status of the monitored space at said predetermined time, activating said simulation means in order for said detector to produce said test signal in response, storing test data in said memory means representative of said test signal, and determining said threshold data as a function of said calibration and test data and storing said threshold data in said memory means for subsequent use in determining said predetermined environmental condition. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25)
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Specification