photo tachometer

例句：

1. 1.The photo tachometer is used to measure the distance traveled by the car.
   照片计程器用于测量汽车行驶的距离。
2. 2.The driver must use the photo tachometer to keep track of their speed.
   驾驶员必须使用照片计程器来跟踪他们的速度。
3. 3.The photo tachometer was a revolutionary tool that helped improve road safety.
   照片计程器是一种革命性的工具，有助于提高道路安全。