The oscilloscope is basically a graph-displaying device - it draws a graph of an electrical signal.
Vertical (Y) axis = voltage
Horizontal (X) axis = time
An oscilloscope looks a lot like a small television set, except that it has a grid drawn on its screen and more controls than a television. The front panel of an oscilloscope normally has control sections divided into Vertical, Horizontal, and Trigger sections. There are also display controls and input display
This simple graph can tell you many things about a signal
• You can determine the time and voltage values of a signal.
• You can calculate the frequency of an oscillating signal.
• You can see the "moving parts" of a circuit represented by the signal.
• You can tell if a malfunctioning component is distorting the signal.
• You can find out how much of a signal is direct current (DC) or alternating current (AC).
• You can tell how much of the signal is noise and whether the noise is changing with time.
Oscilloscopes are used by everyone from television repair technicians to physicists. They are indispensable for anyone designing or repairing electronic equipment. The usefulness of an scilloscope is not limited to the world of electronics. With the proper transducer, an oscilloscope can measure all kinds of phenomena. A transducer is a device that creates an electrical signal in response to physical stimuli, such as sound, mechanical stress, pressure, light, or heat. For example, a microphone is a transducer. An automotive engineer uses an oscilloscope to measure engine vibrations. A medical researcher uses an oscilloscope to measure brain waves. The possibilities are endless
In conclusion, you need to adjust three basic settings to accommodate an incoming signal:
• The attenuation or amplification of the signal. Use the volts/div control to adjust the amplitude of the signal before it is applied to the vertical deflection plates.
• The time base. Use the sec/div control to set the amount of time per division represented horizontally across the screen.
• The triggering of the oscilloscope. Use the trigger level to stabilize a repeating signal, as well as triggering on a single event.