level signal的用法和样例：
例句
- Also, their isolation is limited by the leakage currents of the semiconductor devices, and they have a high insertion loss for low level signals.
此外，其隔离受半导体器件漏流的限制，并且对低电平信号具有较高的插入损耗。 - When the pest crawls through the electro-optical sensor, it will produce a high level signals and begins to count the pulse signal, the count to the pest's number can be realized.
当虫子通过光电传感器时，光电传感器输出高电平信号对脉冲信号进行计数，就实现了对虫子数量的统计。
