Dual-Sensor Gas Detection for Rapid Concentration Changes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gas sensors that measure gas concentration by heating thermistors struggle to accurately follow rapid variations in gas concentration due to prolonged dummy heating periods, leading to measurement delays and inaccuracies.
Innovation Solution
A gas sensor design with two sensor parts and a signal processing circuit that alternates between gas concentration measurement and dummy heating operations, using different temperature ranges for each part to stabilize measurements and reduce thermal history differences, allowing for high-frequency concentration detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a dummy heating period is provided after measurement operation to reduce thermal history difference between detection and reference thermistors, then measurement stability is improved, but measurement period is prolonged causing the sensor to fail to follow rapid gas concentration variations
Solution Approach 1:
The sensor is divided into two independent sensor parts: a first sensor part that alternates between measurement and dummy heating operations to stabilize thermal history, and a second sensor part that performs continuous high-frequency measurements. This segmentation allows each part to specialize in different functions, resolving the contradiction between measurement stability and response speed.
Solution Approach 2:
The first sensor part implements periodic alternation between gas concentration measurement operations and dummy heating operations. This periodic action stabilizes the thermal history difference between thermistors over time while maintaining an overall measurement capability, balancing stability requirements with measurement frequency.
2Stability of the object's composition
If the measurement period is prolonged to include dummy heating operations, then thermal history difference between thermistors is reduced, but the sensor cannot track rapid gas concentration changes
Solution Approach 1:
The sensor system is segmented into two functional units: the first sensor part dedicated to thermal stabilization through periodic dummy heating, and the second sensor part dedicated to high-speed continuous measurement. This segmentation allows the system to achieve both thermal history consistency and fast response speed simultaneously.
Solution Approach 2:
The system changes operational parameters dynamically by switching between two sensor parts with different operational modes. The first part uses periodic heating/cooling cycles to stabilize thermal parameters, while the second part maintains continuous heating for rapid response, adapting parameters based on measurement requirements.
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 sensor effectively tracks rapid gas concentration changes by stabilizing measurements and reducing temporal drift, ensuring accurate and timely detection of gas concentrations even when they vary significantly in short times.
Implementation Method 1
a first heater configured to heat the first temperature-sensitive element, and a second heater configured to heat the second temperature-sensitive element
Data Source
AI summary
Disclosed herein is a gas sensor that includes a first sensor part configured to output a first detection signal, a second sensor part configured to output a second detection signal, and a signal processing circuit configured to control the first and second sensor parts and calculate a concentration of a gas to be detected based on the first and second detection signals. The signal processing circuit is configured to alternately repeatedly execute a first gas concentration measurement operation and a first dummy heating operation when controlling the first sensor part. The signal processing circuit is configured to repeatedly execute a second gas concentration measurement operation without executing a dummy heating operation when controlling the second sensor part. An execution frequency of the second gas concentration measurement operation is higher than an execution frequency of the first gas concentration measurement operation in a first operation period.