Abstract: Common methods of measuring the electromotive force and internal resistance of electric source are the voltammetry and the potentiometer method.However there are some imperfections in the two methods,such as great errors in the measurement results and complex experimental procedures and so on.Thus,the electromotive force and the internal resistance of the electric source are measured with a new method of a self-designing compensation circuit,which has clear experimental principle and relatively simple measurement procedures.This new method needs no special equipments but produces comparatively accurate result.

Key words: electric source, internal resistance, compensation circuit, voltammetry, potentiometer