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.
Vertical Kymograph. maker, source: E. Zimmermann, Leipzig marked: 1907, No. 271. l x w x h; 36 x 19 x 64 cm "An instrument used to record the temporal variations of any ...
ky·mo·graph (k m-gr f) n. An instrument for recording variations in pressure, as of the blood, or in tension, as of a muscle, by means of a pen or stylus that marks a rotating ...