測量微弱的電壓信號時。測量系統中熱電勢的影響不能忽略。本文所討論的基于增量
模型的變極性測量方法是消除測量系統中熱電勢干擾的一種處理方法。這種方法將一個完整的測量過程分為三步，在測量過程中，間隔地變換激勵電流的極性。測量數據經過處理后，得到待測電壓的測量值。理論和實踐均表明，利用該方法可以有效地去除測量系統中絕大部分由于溫度變化而引起的熱電勢的變化對測量結果的影響，提高測量精度。
關鍵詞：增量模型，變極性方法，熱電勢
Research and Application of the Alternating Polarity Method based on
Increment model JIANG XIAOPING（Beijing Campus, China University of Mining and Technology, BEIJING 100083） Abstract: In low voltage measurements, the resulting voltage will be very small and great care needs to be taken to reduce offset voltage and noise. A new Alternating Polarity method based on increment model is researched in this article. With this method, one measurement is divided into three steps, and the polarity of test current is alternated during measurement..A correlative method is treated with these test data for the
final reading. Both theory and practice indicate this method clearly offers significant advantages over other low voltage measurement techniques in overcoming error due to changing temperature.
Key words: Increment model, Alternating Polarity Method, Electromotive Force