已知在若干非电量的电测技术中,需要通过传感器把非电量转换成电量,再利用桥式线路进行检测.但非电量经转换后的电量往往是非常微弱且变化又极其缓慢的非周期性信号,采用桥式线路直接进行测量常常受电桥灵敏度和非线性的限制,给测量带来一定的困难.但若利用桥式线路和运放直接耦合的放大电路,则会在提高测量灵敏度和改善测量线性方面得到意想不到的良好效果,给直接测量提高极大的方便.虽然这种线路在计算上比较复杂,但利用运算放大器的有关特性,对该线路作某种近似计算却是方便可行的.图1给出这种线路的 It is known that in some non-electrical measurement techniques, non-electrical energy needs to be converted into electrical energy by a sensor and then detected by a bridge line, but the non-electrical converted electrical energy is often very weak and very slowly changing aperiodic Sex signal, the direct measurement by bridge line is often limited by the sensitivity and non-linearity of the bridge, which brings some difficulties to the measurement.However, if the amplification circuit directly coupled with the bridge line and the operational amplifier is used, the measurement sensitivity And to improve the measurement of the linearity of the unexpected good results, to improve the direct measurement of great convenience .Although this line in the calculation of the more complex, but the use of operational amplifiers related characteristics of the line for some approximate calculation is convenient Feasible. Figure 1 shows this line