Introduction

　　In 1822， Thomas Seebeck， an Estonian physician， accidentally joined semicircular pieces of bismuth and copper （Figure 1） while studying thermal effects on galvanic arrangements. A nearby compass indicated a magnetic disturbance. Seebeck experimented repeatedly with different metal combinations at various temperatures， noting relative magnetic fi eld strengths. Curiously， he did not believe that electric current was fl owing， and preferred to describe the effect as “thermo-magnetism.” He published his results in a paper， “Magnetische Polarisation der Metalle und Erze durch Temperatur-Differenz” （see references）。

　　Subsequent investigation has shown the “Seebeck Effect” to be fundamentally electrical in nature， repeatable， and quite useful. Thermocouples， by far the most common transducer， are Seebeck’s descendants.

　　熱電偶的視角

　　溫度是最常用的測量方法物理參數(shù)。許多傳感器提供溫度測量需求和每個有優(yōu)勢和注意事項。在討論熱電偶為基礎(chǔ)測量這些傳感器是值得的觀點。圖2顯示了一些常見的聯(lián)系溫度傳感器和列表特性。研究揭示了熱電偶的優(yōu)勢和劣勢相比其他傳感器。一般來說，熱電偶是便宜的，寬量程傳感器。他們的小尺寸使他們快速和他們的低輸出阻抗是一個有益的T.固有電壓輸出消除了勵磁的需要。