摘要或動機

席貝克效應〈Seebeck effect〉是熱能與電能之間的一種固態能量轉換方式，當兩種不同性質的金屬導線之端點連接形成封閉迴路時，若兩接點間有溫差，則兩接點間可測得電壓，而因單位溫差所產生的電壓差稱為席貝克係數〈Seebeck coefficient〉。由本實驗的結果發現：溫差大小、導線特性〈熱電係數〉、導線表面有無氧化層是影響席貝克效應中電壓值及席貝克係數大小的原因。溫差越大，電壓值越大。鉑〈Pt〉與其他金屬的熱電偶導線組合之熱電轉換效能為Pt-Fe > Pt-C > Pt-Al > Pt-Sn；導線的表層若有氧化層，會造成電壓在上升過程中穩定性不佳，產生高低起伏的跳動溫壓曲線，但在較高溫差時，溫壓曲線趨於穩定上升狀態。The Seebeck effect is one of thermoelectric effect. A voltage existed between two ends of different metal wires when a temperature gradient existed between the two junctions. This means the conversion of temperature differences directly into electricity. The voltage induced was called electromotive force, EMF. The EMF generated was dependent on the properties of the wires, which formed the thermocouple and the temperature difference between the junctions. This paper was to study the effect of variety of wire combinations and geomtric properties of wires in thermocouple on the Seebeck coefficient generated. The results indicated that temperature difference, wire properties, and absence or presence of oxidative layer on the surface of wires were the factors to affect the magnitude of voltage and the Seebeck coefficient. As the temperature difference between the junctions was increased, the voltage increased. The combination effiency of conversion of temperature difference into electricity of platinum was following： Pt-Fe > Pt-C > Pt-Al > Pt-Sn. The presence of oxidative layer on the surface of wires caused instability during the process of voltage increase. It made the temperature-voltage curve up and down. On the contrary, when the temperature difference was big, the temperature-voltage curve became increased stably. The temperature-voltage curve was independent of geomtric properties of wires.