How to Use the Oscilloscope

An oscilloscope is a device that displays the voltage of an input signal or some quantity that can be converted into a voltage. It typically shows the amplitude of this voltage on the vertical axis and shows time on the horizontal axis. An oscilloscope is most effective for showing a signal that repeats itself or changes slowly over time. The first uses of an oscilloscope are usually to observe the waveforms of simple signals.

Instructions

1. Connect a lead from an electrical source to the oscilloscope's input terminals. Many oscilloscopes have more than one pair of input terminals, so you'll typically connect the signal to channel 1. Turn the oscilloscope on.

2. Select a scale on the oscilloscope that's appropriate for the input signal. The scale is the amount of time that's represented by a horizontal length on the oscilloscope. For a 1,000 Hz (1 kHz) signal, the signal is repeating itself 1,000 times per second. To see a complete cycle of the signal, you'll need to set the oscilloscope to show at least a millisecond of data.

3. Choose the range on the oscilloscope that matches the input signal. The range is the minimum and maximum voltages that the oscilloscope can display. For a signal that varies between +1 and -1 volts, you would need to set the range to at least 1 volt.

4. Set the oscilloscope's threshold. An oscilloscope must receive a signal that's higher than its threshold value before it will begin displaying the signal. For a 1-volt signal, you might set the threshold trigger on channel 1 to 1/2 volt.

5. Observe a simple voltage signal. The dot on the oscilloscope moves in an up-and-down pattern resembling a sine wave. The minimum and maximum heights of the signal indicate the voltage range, and the amount of time required for the signal to repeat itself is the signal's frequency.

References

• Bucknell University