Kymograph
![A kymograph displays position along a line over time. In this kymograph, made from the film shown, a line across the center of a pizza is shown, and time progresses from top to bottom.](/Images/godic/202501/23/-Kymograph.webm2841.jpg")
A kymograph (which means 'wave writer') is a device that gives a graphical representation of spatial position over time in which a spatial axis represents time. It basically consists of a revolving drum wrapped with a sheet of paper on which a stylus moves back and forth recording perceived changes of phenomena such as motion or pressure.