Definitions
1.NounAn instrument attached to a locomotive for recording its speed and the number and duration of its stops.
2.NounA device used to measure the flow and velocity of liquids.
3.NounAny of various devices that continuously record several meteorological phenomena; a radiosonde or one of its precursors.
4.NounA device that uses reflection holograms to accurately measure three-dimensional objects, used primarily in orthodontics.