Fire Detector Using Dual Gas Concentration Logic
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Solution Overview
Problem
Existing fire detectors often result in false notifications due to the reliance on learning threshold values, which can lead to delayed actual operation and false alarms from non-fire sources like steam or cooking smoke.
Innovation Solution
A detector system that includes sensors for smoke and carbon monoxide concentrations, along with a processing device that selects between two conditions based on the rate of change in these measurements to determine if a fire is present, thereby reducing false notifications without the need for learning threshold values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If learning threshold values is used to improve reliability of fire detection, then detection reliability is improved, but the time to start actual operation increases
Solution Approach 1:
The system performs preliminary learning of threshold values during a setup period before actual operation begins. This preliminary action stores the learned thresholds in memory, so that when actual fire detection starts, the system can immediately use these pre-learned thresholds without needing to learn them in real-time, thus avoiding delay in operational start-up while maintaining detection reliability
2Speed
If only smoke concentration threshold is used for fire determination, then the system responds quickly, but false notifications occur from non-fire sources like steam or cooking smoke
Solution Approach 1:
The system merges multiple detection parameters by simultaneously monitoring both smoke concentration and carbon monoxide concentration. The fire determination logic requires that both parameters exceed their respective thresholds, combining the quick response capability of smoke detection with the reliability of carbon monoxide detection to eliminate false alarms from steam or cooking smoke while maintaining fast response to actual fires
3Reliability
If dual parameter monitoring (smoke and carbon monoxide) is implemented, then false notifications are suppressed, but device complexity increases
Solution Approach 1:
The system segments the detection function into two independent sensor modules: a smoke concentration sensor and a carbon monoxide concentration sensor. Each sensor independently monitors its specific parameter and outputs signals to the determination unit. This segmentation allows the system to achieve reliable dual-parameter monitoring while keeping each component simple and modular, making the overall system easier to manufacture and maintain despite the increased functionality
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system effectively suppresses false notifications and improves the accuracy of fire detection by using real-time concentration and rate of change data from smoke and carbon monoxide sensors, allowing for timely and reliable fire detection.
Implementation Method 1
a first sensor configured to measure a concentration of smoke in air
Implementation Method 2
a second sensor configured to measure a concentration of carbon monoxide in air
Data Source
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AI summary
An objective is to suppress false notification without learning threshold values. The detector (10) includes a first sensor (111), a second sensor (112), a processing device (12), and a notifying device (13). The processing device determines whether a predetermined condition is satisfied with regard to a concentration of smoke measured by the first sensor (111) and a concentration of carbon monoxide measured by the second sensor (112). The processing device (12) selects either a first condition or a second condition as the predetermined condition based on a result of determination of whether a switching condition for the concentration of smoke is satisfied. The first condition is for either the concentration of smoke or the concentration of carbon monoxide. The second condition is for both the concentration of smoke and the concentration of carbon monoxide.