本論文根據渦電流的原理，設計一台經濟型以FPGA為架構之掃頻式阻抗分析儀並應用於金屬薄膜厚度的量測。渦電流檢測系統需要有快速的數據運算處理能力、檢測靈敏度高的探頭、及記憶體進行資料儲存。本研究以數位邏輯電路為基礎，採用FPGA現場可程式邏輯閘陣列進行系統的硬體功能開發。搭配高速的DAC與ADC轉換模組，而構成此多頻率的掃頻系統。再運用強大的個人電腦分析能力，整合軟硬體功能，實現以FPGA為架構之掃頻式阻抗分析儀，實際檢測鋁、銅及鈦金屬薄膜的厚度來驗證此系統的可行性。在系統運作模式上，提供兩種操作模式，首先對金屬薄膜待測物使用自動掃頻的渦電流量測模式，可快速的找出適合目前的探頭線圈參數及金屬待測物特性組合的幾種特徵操作頻率。其次再啟用手動多頻模式，針對這幾個特徵頻率點進行單頻渦電流檢測分析，從中找出最佳的操作頻率。使用最佳操作頻率，可更快速且更靈敏的完成阻抗測量。由實驗證實，以本系統來快速檢測金屬待測物厚度是可行的。

According to the principle of eddy currents, an economical multi-frequency swept impedance analyzer is designed to estimate the thickness of metal foils. Eddy-current testing systems require fast data computing capability, probe with high testing sensitivity, and memory for data storage. Based on digital circuits, this system uses the FPGA development platform to develop the system functions and combines high-speed DAC and ADC conversion modules to compose the multi-frequency swept system. A powerful personal computer analysis ability is applied to implement a multi-frequency swept impedance analyzer inspection instrument. The thicknesses of aluminum, copper, and titanium metal foils are tested to verify the feasibility of this system. First, the metal foils are proceeded auto-frequency swept mode analysis within fixed frequency to find out the optimal discrimination frequency of metal foil thicknesses. Manual frequency-swept mode is then started for impedance measurement and analysis aiming at characteristic frequency. The experiment shows that this system could rapidly inspect the metal foil thicknesses.

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