Ion Current Measurement Stabilizing Ceramic Substrate Resistance
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Solution Overview
Problem
Ion current measurement apparatuses face accuracy issues due to temperature changes in the detection section, particularly in ceramic substrate-based systems where electrical resistance varies with temperature, affecting the accuracy of ion current detection.
Innovation Solution
An ion current measurement apparatus with a control section that adjusts the supply of electricity to a conductor within the detection section, allowing it to function as a heater and maintain a predetermined resistance, thereby reducing the impact of ambient temperature changes on detection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the substrate is formed of ceramic to enable ion current measurement, then the ion current value can be detected, but the electrical resistance of the substrate strongly depends on temperature, causing deterioration of detection accuracy
Solution Approach 1:
The patent applies parameter changes by actively controlling the substrate temperature to a predetermined value, thereby changing the resistance parameter to a stable state. The control section adjusts the heater power to maintain the substrate at a target temperature, ensuring consistent ion current measurement accuracy regardless of ambient temperature variations.
Solution Approach 2:
The patent implements feedback control where the control section continuously monitors the substrate temperature and adjusts the heater power accordingly. This closed-loop feedback mechanism ensures the substrate maintains a predetermined temperature, compensating for temperature-induced resistance changes and maintaining measurement accuracy.
2Device complexity
If the substrate temperature is allowed to vary with ambient conditions, then the device structure remains simple, but the ion current measurement accuracy deteriorates due to resistance changes
Solution Approach 1:
The patent applies multi-functionality by making the heater serve dual purposes: it acts as both the ion current detection electrode and the temperature control element. The same heater that enables ion current measurement also functions as the heating element for temperature stabilization, eliminating the need for separate temperature control components and reducing overall system complexity.
Solution Approach 2:
The system performs self-service by using the heater to simultaneously achieve ion current detection and temperature stabilization. The control section automatically adjusts the heater power based on temperature feedback, allowing the system to self-regulate and maintain optimal measurement conditions without external intervention.
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 stabilizes the detection accuracy of ion current values by controlling the substrate resistance, minimizing the influence of temperature fluctuations and maintaining accurate ion current measurements even with varying ambient temperatures.
Implementation Method 1
the first conductor may be a heating element which generates heat when electricity is supplied thereto
Data Source
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AI summary
An object is to mitigate the influence, on the accuracy in detecting an ion current value, of a change in the temperature of a detection section which detects the ion current value. A detection section includes first and second conductors and a substrate and is attached such that the substrate is exposed to a space in which ions are generated as a result of combustion of fuel. The substrate is formed of ceramic, and the first and second conductors are separately embedded and held in the substrate. A measurement section measures the value of current flowing through the second conductor as an ion current originating from the generated ions. An obtainment section obtains the electrical resistance of the substrate between the first conductor and the second conductor. The problem is solved by providing a correction section or a control section. The correction section corrects the current value measured by the measurement section on the basis of the electrical resistance obtained by the obtainment section. The control section controls the supply of electricity to the first conductor such that the electrical resistance obtained by the obtainment section becomes equal to a predetermined value. In the case where the control section is provided, the measurement section measures the current value in a state in which the supply of electricity to the first conductor is controlled by the control section.