一、原理和结构1.原理用惠斯登电桥测量超高阻时,被测电阻R_X 和标准电阻 R_S 为超高电阻,构成电桥比率臂和测量边的其他两边的电阻 R_A、R_B 为中～高电阻。因此,根据指零仪的连接方法,可以设想两种电桥电路,如图1(a)、(b)所示。图1(a)虽然电桥指零仪的总灵敏度高,但由 First, the principle and structure 1. Principle When using the Wheatstone bridge to measure ultra-high resistance, the measured resistance R_X and standard resistance R_S for the ultra-high resistance, constitute the bridge ratio arm and the other side of the measuring edge resistance R_A, R_B Medium to high resistance. Therefore, according to the finger zero connection method, you can imagine two kinds of bridge circuit, as shown in Figure 1 (a), (b) below. Figure 1 (a) Although the total sensitivity of the bridge refers to the zero instrument, but from