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How to Read Frequency With an Oscilloscope

Electricity is essential to modern-day society and allows people to have luxuries such as lighting, heating and cooking appliances. There are two main types of electricity: direct current and alternating current. DC electricity is the type delivered by batteries, where as AC electricity is the type delivered by electrical outlets. AC electricity, as it name suggests, oscillates between positive and negative voltage at a certain frequency. This frequency can be measured using an oscilloscope or digital voltmeter.

Things You'll Need

Oscilloscope

Instructions

- 1
  Plug the source of AC electricity into one of the oscilloscope inputs. The inputs are normally labeled A and B. The screen on an oscilloscope plots voltage on the y-axis and time on the x-axis. The scales for each axis have to be set correctly in order to see a clear sinusoidal signal.
- 2
  Switch on the oscilloscope. Change the voltage/div dial until a trace is visible. The voltage/div knob allows the y-scale to be changed such that each square on the oscilloscope screen represents a different value of voltage.
- 3
  Change the time/division knob until a clear sinusoidal signal is visible. When a sinusoidal signal is clear visible, take a note of the current time/division value. Count the number of squares from peak to peak on the sinusoidal signal. Multiply the number of squares by the time/division value. This gives the total period of the sinusoidal signal. Use the following equation to calculate the frequency:
  
  Frequency = 1 / total period
  
  The unit of frequency is Hertz.

Nature