本研究主要採用三種系列鋼材，分別為不鏽鋼(AISI 410、AISI 630)、熱作工具鋼(AISI H10、AISI H13)與冷作工具鋼(AISI A2、AISI A6)。在高真空環境下分別把溫度加熱至700K、800K、900K，探討鋼材表面放射率受到波長、合金成份、加熱時間、加熱溫度之影響，並與開放環境下之鋼材表面放射率特徵做比較，以了解氧化效應對放射率特徵的影響。接著利用多光譜輻射測溫法搭配線性與對數線性放射率模組，來預測其無氧化試件表面溫度，並針對波長個數、放射率模組階數、加熱溫度來探討預測溫度之影響，最後再與有氧化試件表面之預測溫度來做比較，以了解氧化效應對溫度預測的影響，並且找出最佳的放射率模型。
無氧化鋼材表面放射率的特徵：(1)所有鋼材放射率皆隨著波長增加而下降；(2)當鉻含量越高時，放射率隨溫度上升幅度較低，而整體放射率也越低；(3)整體而言，鋼材試件放射率隨時間而保持穩定；(4)所有鋼材放射率皆隨著溫度增加而上升。
氧化效應對於鋼材表面放射率特徵之影響：(1)氧化效應對於不同波長及合金成份的鋼材放射率之影響上，不會改變放射率的趨勢；(2)在不同加熱時間下，鋼材的氧化會造成熱作工具鋼及冷作工具鋼之放射率隨著時間增加而變化；(3)受到微氧化層揮發與鋼材結構變化之影響，造成有氧化之鋼材放射率並不隨著溫度增加而上升。
多光譜輻射測溫法對於無氧化鋼材之應用分析：(1)放射率模組總體的表現上，增加波長數對於推論溫度無法提升其精確性；(2)對於不同合金及不同溫度上在挑選放射率模組的階數時，其推論溫度的精確性為一階線性與對數線性放射率模組有最佳的表現；(3)在700K和900K的時候，一階線性放射率模組有最佳的結果，在800K的時候，一階對數線性放射率模組有最佳的結果，並且其誤差皆在4%以內，但整體來說一階線性放射率模組會有最佳的推論結果。
氧化效應對於預測鋼材表面溫度之影響：(1)氧化效應並不會造成在挑選最佳放射率模組階數上的不同；(2)氧化效應會造成利用最佳放射率模組在推論溫度時，其精確性有下降的趨勢；(3)不論在有氧化或無氧化的情況下，若放射率模組越符合鋼材表面放射率行為，所推論出的溫度誤差也越小。

In this study, we use three series of steel, stainless steel (AISI 410, AISI 630), hot work tool steel (AISI H10, AISI H13) and cold work tool steel (AISI A2, AISI A6), at 700 K, 800 K and 900 K under high vacuum condition to examine the surface emissivity which is varied with wavelength, alloy composition, heating time and temperature. The data are then compared with the samples under open-air condition to understand the effect of surface oxidation on emissivity characteristics. We use multispectral radiation thermometry (MRT) with linear emissivity model (LEM) and log-linear emissivity model (LLE) to predict the surface temperature of unoxidized steel samples and examine the effects of wavelength number, order of emissivity model and heating temperature. Then we compare the results with oxidized steel to understand the effect of surface oxidation on temperature determination and find the best MRT emissivity model as well.
The emissivity characteristics of unoxidized steel: (1) emissivity decreases with increasing wavelength; (2) steel with higher chromium component has lower emissivity value; (3) overall, emissivity of steel won’t change with time; (4) emissivity increases with increasing temperature.
The effect of surface oxidation on steel emissivity characteristics: (1) the effect of surface oxidation won't change the trend of steel emissivity for different wavelengths and alloy compositions; (2) surface oxidation will cause the emissivity of hot work tool steel and cold work tool steel to change with increasing time; (3) emissivity of oxidized steel won’t increase with increasing temperature due to the evaporation of micro-oxidized layer and the change of steel structure.
For the examination of multispectral radiation thermometry (MRT) of the unoxidized steel: (1) increasing wavelength number can not improve measurement accuracy; (2) compared with the other orders of emissivity model, the first-order linear emissivity model and the first-order log-linear emissivity model have the best accuracy of inferred temperature; (3) the first-order linear emissivity model has the best results at 700K and 900K, and the first-order log-linear emissivity model has the best results at 800 K. The average errors of inferred temperature are less than 4%. Overall, the first-order linear emissivity model is the best model.
The effect of surface oxidation on surface temperature prediction: (1) the effect of surface oxidation makes no difference when we examine the best order of the emissivity model; (2) the effect of surface oxidation will cause the accuracy of inferred temperature to decrease while using the best emissivity model; (3) if the real emissivity behaviors can be well represented by the emissivity model, the more accurate inferred temperature can be achieved both in oxidized and unoxidized conditions.

1. Khan, M. A., Allemand, C. and Eagar, T. W., “Noncontact Temperature Measurement. I. Interpolation Based Techniques,” Temperature Measurement, Vol. 62, pp. 392-402, 1991.
2. Gorbatenko, I. V., Zaitsev, V. A. and Taimarov, M. A., “Emissivity of Steels and Alloys in the Spectral Region 2-13μm,” Journal of Engineering Physics and Thermophysics, Vol. 50, No. 4, pp. 441-444, 1986.
3. Tsai, B. K., Shoemaker, R. L., Dewitt, D. P., Cowans, B. A., Dardas, Z., Delgass, W. N. and Dail, G. J., “Dual-Wavelength Radiation Thermometry: Emissivity Compensation Algorithms,” International Journal of Thermophysics, Vol. 11, pp. 269-281, 1990.
4. Campo, L. D., Pérez-Sáez, R. B., Tello, M. J., “Iron Oxidation Kinetics Study by using Infrared Spectral Emissivity Measurements below 570℃,’’ Corrosion Science, Vol. 50, pp. 194-199, 2008.
5. Mott, N. F., Cabrera, N., Rep. Prog. Phys., pp. 163-184, 1949.
6. Perez, N., “Electrochemistry and Corrosion Science,’’ Kluwer Academic Publishers, Boston, 2004.
7. Furukawa, T., and Iuchi, T., “Experimental Apparatus For Radiometric Emissivity Measurements of Metals,” Review of Scientific Instruments, Vol. 71, pp. 2843-2847, 2000.
8. Otsuka, A., Hosono, K., Tanaka, R., Kitagawa, K. and Arai, N., “A Survey of Hemispherical Total Emissivity of the Refractory Metals in Practical Use,” Energy, Vol. 30, pp. 535-543, 2005.
9. Rink, M., Bauer, W. and Oertel, H., “SPECTRAL EMISSIVITIES OF BRIGHT AND OXIDIZED METALS AT HIGH TEMPERATURES,’’ Fifteenth Symposium on Thermophysical Properties, 2003.
10. Pellerin, M. A., “Multispectral Radiation Thermometry for Industrial Application,” PhD Thesis, Purdue University, school of Mechanical Engineering, 1999.
11. Haugh, M. J., “Infrared Thermometry for Low Emissivity Metals,” ISA Transactions, Vol. 22, No. 3, pp. 27-31, 1983.
12. Haugh, M. J., “Radiation Thermometry in the Aluminum Industry,” Theory and Practice of Radiation Thermometry, D. P. DeWitt and G. D. Nutter, ed., John Wiley and Sons, New York, pp. 905-971, 1988.
13. Kanayama, K., “Apparent Directional Emittance of V-Groove and Circular-Groove Rough Surface,” Heat Transfer Japn. Res. 1, 1972.
14. Kanayama, K. and Baba, H., “Directional Monochromatic Emittance of the Random Surface of Metals and Non-Metals,” Heat Transfer Japn. Res. 5, 1976.
15. Kobayashi, M., Ono, A., Otsuki, M., Sakate, H. and Sakuma, F., “A Database of Normal Spectral Emissivities of Metals at High Temperatures,’’ International Journal of Thermophysics, Vol. 20, pp. 299-308, 1999.
16. Khan, M. A., Allemand, C. and Eagar, T. W., “Noncontact Temperature Measurement. II. Least Squares Based Techniques,” Temperature Measurement, Vol. 62, pp. 403-409, 1991.
17. Gardner, J. L., Jones, T. P. and Davies, M. R., “A six-Wavelength radiation pyrometer,’’ high temperature-high pressures, Vol. 13, pp. 459-466, 1981.
18. DeWitt, D. P., “Introduction to Radiation Thermometry,” Proceedings of the Aluminum Association Workshop on Sensors, pp. 19-39, 1986.
19. Creighton, J. R., Breiland, W. G., Koleske, D. D., Thaler, G. and Crawford, M. H., “Emissivity-correcting mid-infrared pyrometry for group-lll nitride MOCVD temperature measurement and control’’, Elsevier science b. v. all reserved. Journal of crystal growth, pp. 1062-1068, 2008.
20. Doloresco, B. K., “Review of Multispectral Radiation Thermometry and Development of Constrained Minimization Method,” M. S. Thesis, Purdue University, school of Mechanical Engineering, West Lafayette, 1986.
21. Incropera, F. P. and DeWitt, D. P., “Fundamentals of Heat and Mass Transfer,” 5th ed, John Wiley and Sons, New York, pp. 700-756, 2002.
22. Ji, J., Gore, J. P., Sivathanu, Y. R. and Lim, J., “Fast Infrared Array Spectrometer used for Radiation Measurements of Lean Premixed Flames,” Proceedings of NHTC, 34th National Heat Transfer Conference, Pittsburgh, PA, pp. 1-6, 2000.
23. Pellerin, M. A., “Multispectral Radiation Thermometry: Emissivity Compensation Algorithm,” M.S. Thesis, Purdue University, school of Mechanical Engineering, 1990.
24. Wen, C. and Mudawar, I., “Experimental Investigation of Emissivity of Aluminum Alloys and Temperature Determination Using Multispectral Radiation Thermometry (MRT) Algorithms,” Journal of Materials Engineering and Performance, Vol. 11, pp. 551-562, 2002.
25. Wen, C. and Mudawar, I., “Emissivity Characteristics of Roughened Aluminum Alloy Surfaces and Assessment of Multispectral Radiation Thermometry (MRT) emissivity models,” International Communications in Heat and Mass Transfer, Vol. 47, pp. 3591-3605, 2005.
26. Wen, C. and Mudawar, I., “Emissivity Characteristics of Polished Aluminum Alloy Surfaces and Assessment of Multispectral Radiation Thermometry (MRT) emissivity models,” International Communications in Heat and Mass Transfer, Vol. 48, pp. 1316-1329, 2005.
27. Wen, C., “Emissivity Characteristics of Aluminum Alloy Surfaces and Assessment of Multispectral Radiation Thermometry (MRT) Emissivity Models,” PhD Thesis, Purdue University, school of Mechanical Engineering, 2005.
28. Wen, C. and Mudawar, I., “Modeling the Effects of Surface Roughness on the Emissivity of Aluminum Alloys,” International Communications in Heat and Mass Transfer, Vol. 49, pp. 4279-4289, 2006.
29. Wen, C. and Mudawar, I., “Mathematical Determination of Emissivity and Surface Temperature of Aluminum Alloys using Multispectral Radiation Thermometry,” International Communications in Heat and Mass Transfer, Vol. 33, pp. 1063-1070, 2006.
30. 池逸華, “鋼材放射率行為之實驗研究與線性及對數線性放射率模組在多光譜輻射 測溫法之應用,”碩士論文,國立成功大學機械系, 2007.
31. 呂建財, “鋼材放射特徵研究與多光譜輻射測溫法之應用,” 碩士論文,國立成功大學機械系, 2007.
32. 蔡宗原, “應用線性與對數線性放射率模組於多光譜輻射測溫法預測鋁合金表面溫度之研究,”碩士論文,國立成功大學機械系, 2008.
33. 謝宗霖, “多光譜輻射測溫法放射率模組對預測鋁合金表面溫度的合宜性,”碩士論文,國立成功大學機械系, 2008.
34. 朱閔峙, “鋁合金於真空腔體內之放射率行為實驗研究,”碩士論文,國立成功大學機械系, 2009.
35. 翁亢賢, “氧化效應對多光譜輻射測溫法預測鋁合金表面溫度的影響,”碩士論文,國立成功大學機械系, 2009.