Gas Sensor Calibration Using On-Demand Test Gas Generation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current gas sensor calibration methods are time-consuming, expensive, and cumbersome due to the need for large, bulky test gas cylinders, and they lack accuracy in measuring absolute gas concentrations, as most sensors provide relative output signals that can vary over time.
Innovation Solution
A gas sensor test system utilizing a second, stable and inexpensive test sensor in conjunction with a gas generating device to accurately determine the concentration of test gas introduced to a target sensor, allowing for simultaneous contact and calibration, which can include a thermal conductivity sensor or metal oxide sensor, to support signal analysis and gas flow determination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If large gas cylinders are used for calibration testing, then sufficient test gas can be provided, but the system becomes bulky and expensive
Solution Approach 1:
The patent extracts the test gas from large external cylinders and concentrates it in a compact generation device that produces gas on-demand. The gas generating device includes a reaction chamber with reagents that chemically produce the test gas, eliminating the need for bulky storage cylinders while maintaining sufficient gas supply for calibration.
Solution Approach 2:
The patent changes the physical state and delivery method of test gas from stored gaseous form in large cylinders to generated form through chemical reactions in a compact device. This parameter change allows the system to provide sufficient test gas without requiring large volume storage, thereby reducing system bulkiness.
2Reliability
If frequent calibration is performed, then sensor reliability is maintained, but time and resources are consumed
Solution Approach 1:
The patent implements a self-service calibration system where the gas generating device automatically produces test gas and delivers it to the sensor without requiring manual intervention. The system includes automatic control mechanisms that manage the calibration process, reducing the time and resources needed while maintaining frequent calibration capability for sensor reliability.
Solution Approach 2:
The patent enables continuous or frequent calibration by providing on-demand test gas generation. The gas generating device can rapidly produce test gas and the system can cycle through calibration procedures multiple times without significant interruption, maintaining continuous sensor reliability checking without consuming excessive time or resources.
3Productivity
If relative output signals are used from gas sensors, then sensor output is obtained, but absolute gas concentration measurement is not achieved
Solution Approach 1:
The patent implements a feedback mechanism where the test sensor measures the actual concentration of test gas delivered to the target sensor. This feedback information is used to correct and calibrate the target sensor's output, converting its relative signal into an accurate absolute concentration measurement. The feedback loop ensures that the sensor's response is continuously adjusted to match the known test gas concentration.
Solution Approach 2:
The patent replaces the indirect mechanical measurement approach with a direct chemical measurement approach. Instead of relying on the sensor's relative electrical output alone, the system uses a test sensor to directly measure the chemical concentration of test gas, providing an absolute reference that substitutes for and corrects the target sensor's relative signal.
4Reliability
If calibration test gases are used, then sensor calibration is achieved, but the process becomes expensive
Solution Approach 1:
The patent uses inexpensive, disposable reagents in the gas generating device to produce test gas. Instead of requiring expensive calibration gas cylinders, the system employs affordable chemical reagents that can be easily replaced. This approach maintains the ability to perform frequent calibrations for sensor reliability while significantly reducing the cost per calibration operation.
Solution Approach 2:
The patent employs a system where test gas is generated on-demand from inexpensive reagents and used immediately for calibration. The reagents are consumed and replaced rather than requiring recovery of expensive calibration gas. This discard-and-replace approach with inexpensive reagents is economically superior to recovering and storing expensive calibration gas cylinders.
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
Enables efficient and accurate calibration of gas sensors by providing a reliable method to determine test gas concentration, reducing the need for bulky cylinders and improving reproducibility, allowing for frequent calibration without significant resource constraints.
Implementation Method 1
The test sensor may be utilized to determine the actual concentration of test gas in contact with a target sensor
Implementation Method 2
The test sensor may be utilized to determine gas flows, assisting the calibration or supporting the signal analysis of the gas sensor system
Data Source
AI summary
Embodiments of the present invention relate a gas sensor system comprising a gas generating device adapted to generate a test gas, a target gas sensor positioned near the gas generating device, a test gas sensor positioned near the gas generating device and in communication with the target gas sensor and wherein the test gas sensor is sensitive to the test gas.