MOS Gas Sensor Poison Correction via Dielectric Excitation
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Solution Overview
Problem
Metal oxide semiconductor (MOS) sensors used for gas sensing can be irreversibly poisoned by certain gases, such as siloxane vapor, leading to a loss of their ability to accurately detect gas concentrations.
Innovation Solution
The system employs dielectric excitation at two frequency ranges to determine the poison level of the sensor and correct measured responses, allowing for the identification and concentration of gases in a fluid sample without the need for recalibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional resistance-based MOS sensors are used for gas detection, then the sensors can detect gas concentrations with proper material selection, but the sensors are irreversibly poisoned by certain gases (e.g., siloxane vapor) leading to loss of detection ability
Solution Approach 1:
The patent changes the operating principle of the MOS sensor from resistance measurement to dielectric permittivity measurement. By applying AC voltage at specific frequencies and measuring the imaginary component of the dielectric response, the sensor can detect gases without being irreversibly poisoned by poisoning gases like siloxane vapor, thus maintaining reliability and extending lifespan
Solution Approach 2:
The patent replaces the conventional electrical resistance measurement mechanism with a dielectric excitation and measurement mechanism. Instead of measuring resistance changes, the system measures the imaginary component of dielectric response at specific frequencies, which substitutes the measurement principle to avoid poisoning effects
2Productivity
If MOS sensors are exposed to poisoning gases to maintain continuous operation, then the sensors remain in service, but the measurement accuracy deteriorates due to poison level accumulation
Solution Approach 1:
The patent implements a feedback mechanism where the system continuously monitors the dielectric response of the MOS sensor and uses this information to determine the poison level. Based on the measured poison level, the system adjusts or corrects the gas concentration calculations, maintaining measurement precision even during continuous operation in the presence of poisoning gases
Solution Approach 2:
The patent performs preliminary determination of the poison level by measuring the dielectric response at specific frequencies before conducting gas concentration measurements. This preliminary action allows the system to compensate for poisoning effects and maintain accurate measurements throughout continuous operation
3Ease of operation
If conventional sensors are used without poison level correction, then the system is simple to operate, but frequent recalibration is required to maintain accuracy
Solution Approach 1:
The patent enables the sensor system to self-diagnose and self-correct for poison level effects. By continuously monitoring dielectric response and automatically determining poison levels, the system performs its own calibration maintenance without requiring external intervention or frequent manual recalibration, thus maintaining ease of operation while reducing time loss
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
This approach extends the lifespan of MOS sensors in environments with poisoning materials by enabling continuous accurate gas detection, reducing the frequency of recalibration and resource consumption.
Implementation Method 1
provide first and second dielectric excitation of the gas sensing material at first and second respective sets of frequencies
Implementation Method 2
measure responses of the gas sensing material to the first and second dielectric excitation at the first and second respective sets of frequencies
Data Source
AI summary
A system and a method for gas sensing while correcting for a poison level of a gas sensor. The gas sensor provides first dielectric excitation of the gas sensing material at a first set of frequencies, measures responses of the gas sensing material to the first dielectric excitation while the gas sensing material is in contact with the fluid sample, provides second dielectric excitation of the gas sensing material at a second set of frequencies, measures responses of the gas sensing material to the second dielectric excitation while the gas sensing material is in contact with the fluid sample, and determines, based on the responses of the gas sensing material to the first and second dielectric excitation, identities, respective concentrations, or a combination thereof, of at least one analyte gas in a fluid sample, and a sensor poison level of the gas sensing material.