Composite Metal Oxide Temperature Sensor for High-Temperature Accuracy
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Solution Overview
Problem
Conventional metal oxide temperature sensors fail to accurately measure high temperatures due to low resistance values and are prone to failure under high vibration and temperature conditions, leading to significant measurement errors and frequent replacements.
Innovation Solution
A composite temperature sensor material incorporating metal oxides with yttria and alumina, where electrode wires are inserted during press-molding, allowing for precise resistance control and improved durability through tight contact and heat treatment, enabling accurate high-temperature measurements and vibration resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a metal oxide temperature sensor is used at high temperature, then the sensor can operate in high-temperature environments, but the resistance value becomes very low making accurate measurement difficult
Solution Approach 1:
The patent uses a composite material consisting of a metal oxide base (such as Fe2O3, NiO, Cr2O3, or MnO2) combined with a specific amount of CuO (copper oxide). This composite structure allows the sensor to maintain high-temperature operational capability while the CuO addition modifies the electrical properties to achieve suitable resistance values at elevated temperatures, thereby resolving the measurement accuracy issue.
2Ease of manufacture
If an electrode is printed or plated on the test piece surface and attached with an electrode wire, then the temperature sensor can be manufactured, but the electrode wire becomes sensitive to temperature and vibration causing detachment
Solution Approach 1:
The patent incorporates the electrode wire into the test piece during the pressing and sintering process itself, rather than attaching it afterward. The wire is placed in a groove or cavity formed in the test piece before sintering, allowing it to become integrally bonded to the ceramic structure. This preliminary integration eliminates the separate attachment step that creates vulnerability to vibration and thermal stress.
Solution Approach 2:
The patent merges the electrode wire integration with the main body fabrication process. By forming the wire embedding structure (groove or cavity) and placing the wire before sintering, the electrode connection becomes part of the monolithic ceramic structure, combining the mechanical strength and thermal stability of the ceramic with the electrical functionality of the wire.
3Device complexity
If transition metals alone are used to manufacture the metal oxide temperature sensor, then the manufacturing process is simple, but the resistance at high temperature is very low resulting in large measurement error
Solution Approach 1:
The patent modifies the chemical composition parameters of the metal oxide by adding a specific amount of CuO (copper oxide) to the base metal oxide materials. This compositional parameter change fundamentally alters the electrical resistance characteristics of the material, particularly at high temperatures, bringing the resistance into a measurable range while maintaining the high-temperature operational capability of the original metal oxide system.
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 composite sensor achieves stable resistance values across varying temperatures, reducing measurement errors and enhancing durability, allowing for reliable operation in high-temperature, high-vibration environments.
Implementation Method 1
Temperature sensors are typically made of a metal or a metal oxide... a test piece of a transition metal oxide such as Fe2O3—NiO—Cr2O3—MnO2 is initially manufactured... to accurately measure a resistance at temperatures of 500° C. or more
Implementation Method 2
a test piece of a transition metal oxide such as Fe2O3—NiO—Cr2O3—MnO2 is initially manufactured by a ceramic process of mixing, calcining, and sintering
Data Source
AI summary
A composite material for a temperature sensor and a method of manufacturing the temperature sensor using the composite material are provided. The composite material contains four or more kinds of metal oxides combined with highly insulating materials to produce a material with semiconductor-like properties to more accurately measure a temperature at high temperatures in the range of 500° C. and above. The sensor includes electrode wires having a predetermined diameter inserted into the metal oxide of the temperature sensor when the metal oxide is press-molded to form the temperature sensor. Through the connection of the electrode wires to the temperature sensor device, disconnection of the electrode wires from the device even at a high temperature.