热电偶测量

　　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.

　　热电偶的视角

　　温度是最常用的测量方法物理参数。许多传感器提供温度测量需求和每个有优势和注意事项。在讨论热电偶为基础测量这些传感器是值得的观点。图2显示了一些常见的联系温度传感器和列表特性。研究揭示了热电偶的优势和劣势相比其他传感器。一般来说，热电偶是便宜的，宽量程传感器。他们的小尺寸使他们快速和他们的低输出阻抗是一个有益的T.固有电压输出消除了励磁的需要。