an instrument for producing a representation of a quantity that rapidly changes with time on the screen of a cathode-ray tube. The changes are converted into electric signals, which are applied to plates in the cathode-ray tube. Changes in the magnitude of the potential across the plates deflect the electron beam and thus produce a trace on the screen
An electronic instrument used to observe and measure changing electrical signals. The amplitude of the signal as it varies with time is displayed graphically on a screen as a line stretching from left to right, with displacements up and down indicating the amplitude of the signal. Oscilloscopes are used to diagnose problems in electronic signal-processing devises, such as computers or stereos, and to monitor electrical activity in the body, such as that of heartbeats.