electrograph

noun

1. a curve or plot automatically traced by the action of an electric device, as an electrometer or an electrically controlled pen.
2. Printing. an apparatus for engraving metal plates on cylinders used in printing.
3. Telecommunications.
   1. an apparatus for electrically transmitting pictures.
   2. a picture produced by such a device.

noun

1. an apparatus for engraving metal printing cylinders, esp in gravure printing
2. the equipment used for the electrical transmission of pictures
3. 1. a recording electrometer
   2. a graph produced by this instrument
4. a visual record of the surface composition of a metal, obtained by placing an electrolyte-soaked paper over the metal and passing a current through the paper to an electrode on the other side