答:心电图机的辨差比(C MR R)下降常常是由前级管子特性不对称或者标准电池漏液等原因所造成的。为了区分故障产生的部位,首先取下标准电池至放大板的连接线,再输入1V共模信号,如此时机器记录幅度为1mm,则故障是由标准电池引起的。更换标准电池和连接线,如故障仍不能排除,则进一步用万用表测量固定标准电池的胶木板的 A: ECG Dizhao ratio (CMRR) decline is often caused by the asymmetric characteristics of the previous tube or standard battery leakage and other causes. In order to distinguish the fault generated parts, first remove the standard battery to the amplifier cable, and then enter the 1V common mode signal, so the machine record amplitude of 1mm, the fault is caused by a standard battery. Replace the standard battery and cable, such as failure can not be ruled out, then further use of multimeter to measure the fixed standard battery bakelite