Oscillograph
1. Oscillograph is a device for recording oscillations, especially those of an electric current.
2. Oscillograph is an instrument for indicating and recording time-varying electrical quantities, such as current and voltage.
The two basic forms of the instrument in common use are the electromagnetic oscillograph and the cathode-ray oscillograph; the latter is also known as a cathode-ray oscilloscope (q.v.), which, strictly speaking, is purely an indicating instrument, while the oscillograph can make permanent records.
The operation of an electromagnetic oscillograph, like the operation of a d’Arsonval galvanometer, depends on the interaction of the field of a permanent magnet and a coil of wire through which an electric current is flowing.
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