Monitoring of movable components

摘要

A method and device for monitoring the operation of a component which is located in a sealed enclosure and is movable into a selected operating position in response to an activating signal uses the steps of: generating a short-duration acoustic signal in the enclosure in response to the movement of the component into the selected operating position; sensing the acoustic signal at the exterior of the sealed enclosure; and determining the time relationship between the activating signal and the acoustic signal. The acoustic signal is generated by an element which is carried by or moveable with the component and which generates the acoustic signal by striking an interior surface of the enclosure when the component moves into the selected operating position.