一、引言近年来为改进准确测量直流电压的仪器曾做了相当努力。多年来,采用电阻分压器作电压分度的电位差计勿庸置疑地在这一领域中居于首位。然而,这种电位差计有许多限制。其额定量限仅为几伏;因全部度盘必须手调故使用费时;且难于制成直读准确度高于五个十进盘的这类电位差计。 I. INTRODUCTION In recent years, considerable efforts have been made to improve the accurate measurement of DC voltage instruments. Over the years, the use of resistive divider for voltage divider undoubtedly in this area in the first place. However, this potentiometer has many limitations. Its nominal limit is only a few volts; it is time-consuming to use because all dials have to be hand-adjusted; and it is difficult to make such potentiometers with a direct reading accuracy of more than five decimal lots.