本文研究以微機電技術用來製作薄膜式熱膜感測器陣列器，使用氮化矽(silicon nitride)作為結構層，感測器陣列包含鉑(Platinum)電阻感溫元件陣列以及金(Aurum)金屬連結導線，最後在感測器背後製作蝕刻孔，經濕式蝕刻後即完成薄膜式感測器陣列。此熱膜感測器電阻溫度係數(Temperature Coefficient of Resistance , TCR)可以達到0.238%/℃，以液滴模擬降溫實驗，此感測器對物理訊號之響應頻率可達3.4KHz。

　　本研究主要以自製之薄膜式熱膜感測器運用於渦流流量計，測試其在渦流流量計之實用性以及在管流流場的實驗。實驗中，將感測器封裝於梯形截面鈍形體之中，在風洞實驗的流速範圍Re=10100-41300，可得到其渦流溢放頻率為14.65至58.59Hz之間，將溢放頻率無因次化可得到無因次頻率St(Strouhal Number)約為St=0.093，經測試後溫度感測器安裝於梯形鈍形體後延長平板之最佳位置約為x/d=1.76。

　　此外將已封裝此感測器之梯形型鈍形體放置於一50mm圓管管流之直管完全發展段，並利用熱線測速儀來比對渦流溢放訊號，結果顯示流量計所感測溢放訊號與熱線所得一致，更進一步將流量計安裝於兩不同平面彎管下游，以及於彎管入口處加裝一鈍形體，兩情況顯示在在彎管下游X’=15D-20D位置可得到較佳的訊號品質，此結果有助於在彎管中流量計擺放位置之參考。

　　In this research, an array of membrane thermal film sensors array was manufactured by a MEMS fabrication process. The design was featured with using platinum as sensing material, and Aurum as the conducting wires to connect the platinum sensing material and the circuit, Both platinum and aurum are deposited on silicon nitride substrate. Finally, by wet etching the silicon nitride substrate, the membrane thermal film sensors array was finished. Each of the sensors shows the linear temperature-dependence characteristic, with the coefficient of resistance (TCR) of 0.238% /℃ measured. By imposing a stepwise change of surrounding temperature to a sensor, the constant-current circuit output showed a dynamic response up to 3.4KHz.

　　The membrane thermal film sensors array was applied to a vortex flowmeter for flow measurement. The sensors were packaged in the T-shape vortex flowmeter, for the flow velocity ranging between Re=10100-41300 in low-speed wind tunnel. Thus, the vortex shedding frequencies measured fall between 14.65-58.59Hz. That the non-dimensional frequencies are about St=0.093. From the experiments, the optimal position of the thermal film sensor in vortex flowmeter was found about x/d=1.76.

　　Furthermore, a T-shaped vortex shedder was assembled in a 50mm pipe flow. Hot-wire anemometer was employed to obtain the vortex shedding signal as well. The characteristics of the signals obtained from the vortex flowmeter and the hot-wire probe appeared alike. Further, by placing the flowmeter downstream of two elbows out of plane, with and without T-shaped cylinder upstream of inlet of the elbows, the signal quality corresponding to those two case were compared. Both cases showed that the best signal quality (SNR) can be obtained in X’=15D-20D downstream of the exit of the elbows. The results suggest that a vortex flowmeter be located at this location for flow measurement.

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