split-second timer

例句：

1. 1. The split-second timer on the clock is counting down to the next event.
   钟上的秒差计时器正在倒数下一个事件。
2. 2. The engineer used a split-second timer to ensure that the machine started smoothly.
   工程师使用了秒差计时器来确保机器顺利启动。
3. 3. The scientist used a split-second timer to measure the reaction rate of the chemical reaction.
   科学家使用秒差计时器来测量化学反应的反应速率。