Ultrasonic motion sensor
= Ultrasonic motion sensor
An <ultrasonic motion sensor> estimates distance from the return delay of an <acoustic wave> pulse reflected by a target. The teaching setup places a flat flag on the cart facing the detector above the <air track>, and specifies a minimum range of about $0.3\,\mathrm m$ for its detector. That apparatus-specific limit should not be assumed for every sensor model. <Motion Sensor Setup>{ref}