How Does An Oscilloscope Work?

An oscilloscope (sometimes referred to as a scope or O-scope) is an electronic device which allows you to view the voltage of an electronic signal. Oscilloscopes are used to test and troubleshoot electronic equipment. The voltage is displayed on cathode ray tube or CRT display. This display is broken down into a graph. On the screen is drawn a grid which is called a graticule. The squares within the graticule are called divisions. On this graph the horizontal axis shows the time and the vertical axis shows the voltage. There are also oscilloscopes which can display multiple waveforms. These are used to compare phase or timing of 2 or more signals.

The oscilloscope continually draws a horizontal line from left to right across the middle of the screen. This line is called a trace. If the voltage being measured deviates from zero the trace is moved or deflected upward or downward. You can control the speed at which the trace is drawn with the timebase control. This control is calibrated in seconds per division. You can control the scale of the vertical deflection with the vertical control. The vertical control is calibrated in volts per division. The trace plots the input signal's voltage against time.

Modern oscilloscopes introduced a trigger function which has the benefit of producing a much more stable trace. When you enable the trigger function the oscilloscope pauses when the trace or sweep reaches the right edge of the screen. It then awaits the specified event before the next trace is drawn. Generally the trigger event is the voltage of the input signal reaching a certain value, either positive or negative. The resulting effect is the resynchronization of the input signal to the timebase. This prevents potential horizontal drift of the trace as well as allowing the oscilloscope to display periodic signals. Some examples of periodic signals include square waves and sine waves. The triggering function also makes possible the display of nonperiodic signals such as pulses which don't recur at a fixed rate.

Oscilloscopes are frequently used to troubleshoot electronic equipment which is not functioning correctly. An oscilloscope's ability to display a signal graphically is an advantage over a voltmeter. Sometimes the shape of the pulse is very important from a troubleshooting standpoint. A scope can also show you if the signal is oscillating. When you examine all of the facts it becomes clear that an oscilloscope is an invaluable tool for all electronics technicians.

Some of the most leading manufacturers of oscilloscopes are LeCroy, Agilent Technologies and Tektronix who actually produced the first triggered oscillscope. Browse the selection of new and used oscilloscopes that we have available for sale through our affiliation with eBay - you won't find better prices anywhere else! If you don't see what need, search here to perform a more extensive search.