1. A musical instrument, typically wood, that is held in a vertical position and played by blowing air through it and covering finger holes in the tube of the instrument to produce different sounds: Kirsten was learning to play the recorder after she decided playing the flute was too difficult.
2. A person whose job is to write official data about things that need to be available for current or future reference: Carol is the official recorder for the local housing advocacy committee meetings and in addition to taking hand written notes, she uses an electrically operated machine to be sure she accurately gets all the information from meetings.

A device that transforms electrical signals into equivalent mechanical motion which is transferred to a medium by cutting, embossing, or writing.

1. An instrument in which an electron beam places signals or data on film in a vacuum chamber.
2. A recorder in which a moving electron beam is used to record signals or data on to photographic or thermoplastic film in a vacuum chamber.
3. A device that transfers computer data onto microfilm using an electron beam.

A recorder in which heat produces an image on the recording medium in response to the received signals.

1. A device that gauges frequency distribution of the reflections from different layers in the ionosphere, used in radios.
2. A radio device for determining the distribution of virtual height with frequency, and the critical frequencies of the various "layers" of the ionosphere.

A pulse at a certain frequency is transmitted vertically, and the time for its return is recorded on an oscilloscope; another pulse at a different frequency is then transmitted and timed.

The process is repeated until the entire frequency range of interest, usually from about 1 to 25 MHz, has been explored.

3. A radio device for determining the distribution of virtual height with frequency, and the critical frequencies of the various layers of the ionosphere.

A device with sensors and a recorder, used to record salinity, temperature, and the depth of ocean water.

A delicate automatic receiving instrument used in submarine telegraphy, consisting of a small siphon that discharges ink to make a record that corresponds with the dots and dashes of the Morse code.