metrograph

From metro- +‎ -graph.

metrograph (plural metrographs)

1. An instrument attached to a locomotive for recording its speed and the number and duration of its stops.
   • 1880 December 3, “Watham Watch Gauge”, in English Mechanic and Mirror of Science, volume 32, page 304:

     Metrographs have been devised for counting the revolutions and speed of locomotive wheels.

   • 1961, American Association of Railroad Superintendents, Proceedings and Committee Reports of Annual Meeting, page 85:

     Now, equipment is available today where you can use teletype, punch cards, use a metrograph machine, or a thousand ways.

2. A device used to measure the flow and velocity of liquids.
   • 1929, Contract Record, page 803:

     Represented by R.W. Sparling, and C. F. Sherwood, exhibited the Sparling line of main line meters and metrograph recording instruments.

3. Any of various devices that continuously record several meteorological phenomena; a radiosonde or one of its precursors.
   • 1895 October 12, “How the Weather Bureau Forecasts Storms”, in Digest: Review of Reviews Incorporating The Literary Digest, volume 11, number 24, page 703:

     The automatic records of the sunshine recorder, the anemometer and the wind vane, are registered on one instrument, which is called a metrograph or improved triple register.

   • 1982, M. A. Hewitt, Downtown People Mover (DPM) Winterization Test Demonstration, pages 2-21:

     The metrograph temperature sensor and the two mercury thermometers were backed up by temperature readings from nickel iron resistance thermometers and reported temperature readings from Buckley Air National Guard Base Weather Station.

   • 1992, Preston B. Nichols, Peter Moon, The Montauk Project: Experiments in Time, page 44:

     The government's contribution to the radiosonde dates back to the "airborne metrograph" of the 1920's. This was a mechanical device that recorded temperature, humidity, and pressure.

   • 2023, Ashwin Vinoo, Project Mankind, page 381:

     Since the 1930s, the government would use radio metrographs to monitor the weather.

4. A device that uses reflection holograms to accurately measure three-dimensional objects, used primarily in orthodontics.
   • 1986, Proceedings of the 17th International Congress on High Speed Photography and Photonics, page 270:

     With the metrograph, the hologram is fixed and the point of light can be moved in the three orthogonal directions.

   • 1989, South African Journal of Science - Volume 85, Issues 7-12, page 480:

     […] is shown for the first time that with reflection holograms of orthodontic dental casts, measurements can be made of the quantities required for treatment assessment, to within +-0.2 mm, using a reflex metrograph.

   • 2002, William C. Shaw, Gunvor Semb, “Evidence-based care for children with cleft lip and palate”, in Diego F. Wyszynski, editor, Cleft Lip and Palate: From Origin to Treatment, page 435:

     To relate the subjective assessment of the Goslon Yardstick to objective measurement, overjet, overbite, incisor angulation, and various arch form and crossbite relationships were masured on the same series of study casts using a reflex metrograph.

• tremograph