在日常的修理工作中，接触不良的故障是随处可见的，且存在于各种不同类型的设备中。此类故障的明显表现为设备的功能时好时坏，维修人员的常规检修方法为处理能观察到的明显接触不良处，往往可达到排除故障的目的（在此不涉及因元器件内部接触不良和其它隐蔽性接触不良故障） In daily repair work, poor contact failures are everywhere and exist in a variety of different types of equipment. The obvious manifestation of such failures is that the function of the equipment is good or bad, and the routine maintenance methods of the maintenance personnel are to deal with the obvious contact failures that can be observed, and it is often possible to achieve the purpose of troubleshooting (this does not involve poor internal contact due to components). And other hidden contact failures)