(三)单一扫描单一扫描用于观察和摄影记录某种不再重复出现的一次性信号或者不规则的非周期性信号(如开关接触点间转换的瞬态过程),只有在这些现象发生(或发生以前)的瞬间,才要求开始扫描.当完成一次扫描后,一般并不自动回扫,而往往依靠人工恢复,使其进入下次扫描工作的准备状态.这种单一扫描实质上就是一种触发扫描,其主要区别仅在触发扫描的控制电路中附加一人工控制装置而已,因此不再详述. (C) a single scan Single scan for observation and photography record some no longer repeated one-time signal or irregular aperiodic signals (such as switch contact transition between the transient process), only when these phenomena occur Or before it occurs), the scan is only required to begin.When a scan is completed, it usually does not automatically flyback but often relies on manual recovery to get ready for the next scan. This single scan is essentially a The main difference between this kind of triggering and scanning is that only a manual control device is added to the control circuit that triggers the scanning. Therefore, the detailed description will not be given.