2006 Fiscal Year Final Research Report Summary
Theoretical basis of the response compensation for fine-wire temperature sensors and development for its practical
| Project/Area Number |
17560183
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Thermal engineering
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| Research Institution | Nagoya Institute of Technology |
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Principal Investigator |
TAGAWA Masato Nagoya Institute of Technology, Department of Mechanical Engineering, Professor, 工学研究科, 教授 (80163335)
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| Project Period (FY) |
2005 – 2006
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| Keywords | Temperature Measurement / Sensor / Frequency Response / Time Constant / Response Compensation / Turbulence / Temperature Fluctuation / Thermocouple |
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| Research Abstract |
The research results are summarized as follows:
1.Theoretical analysis of the frequency response of a fine-wire temperature sensor such as a thermocouple or a cold wire was performed, and a strict solution of the response was derived by treating rigorously a boundary condition of heat transport between the temperature-sensing part and its adjoining support. The solution obtained is highly universal and can express the frequency response of both a fine-wire thermocouple and a cold wire with a single equation. The validity of the theoretical solution was examined experimentally, and a response-compensation technique widely applicable to fine-wire temperature sensors was developed based on the theoretical results. The present response-compensation technique can perform fluctuating temperature measurement by a 3.2 μm tungsten wire well comparable to that by a 0.63 μm platinum wire which is regarded as one of the fastest temperature sensors commercially available.
2.Theoretical analysis of th
… More
e frequency response of a fine-wire thermocouple probe has been further developed to investigate influences of the difference in physical properties between the two wires composing a butt-welded fine-wire thermocouple. The solution obtained demonstrates complex behaviors of the frequency response of the copper-constantan (type-T) thermocouple whose physical properties differ greatly between the two constitutive wires. It was also shown that, in an air flow, the frequency response is almost uniform in the cross-section of the thermocouple wire, but, in a water flow, it becomes remarkably non-uniform.
3.A robust response-compensation scheme has been developed to estimate in situ the thermal time constants of fine-wire temperature sensors in the frequency domain. The time-constant values can be obtained by maximizing a coherence function of two "compensated" temperature signals measured simultaneously by two sensors having different time-constants. The scheme was validated experimentally and showed the highest tolerance to instrumentation noise compared with our previous methods. Less
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Research Products
(20 results)
