Oscilloscope Types

• Oscilloscopes made in the 21st century are digitally based, using data acquisition circuitry to translate an input signal such as an audio waveform into a visual display. For example, a pure sine wave sound would be visible on the oscilloscope display as the familiar smooth sine wave. Analog oscilloscopes in the past simply used the input signal to modify the location of a beam drawing a pattern across a television-like screen.
  
  

Oscilloscope Uses

• The key to oscilloscopes is their many adjustments which allow a technician to analyze rapidly changing voltages and recognize familiar patterns such as the "data clock," which is the heart beat of a computer. Oscilloscopes can also display steady voltages, with the advantage that if there is a momentary change, the display will show it. Oscilloscopes graph voltage against time, and can also be set to begin the display when a signal changes.
  
  

DVM Types

• DVMs display voltages in numeric form on a digital display. They are the descendants of the Volt Ohm Meter, or VOM analog voltmeter, which used a needle swinging across a printed scale to indicate voltage. The digital display updates when a time interval elapses, usually a very short one. Watching displayed numbers change can give some indication of a trend. DVMs usually include functions to measure current (Amperes) and resistance (Ohms). DVMs can be made very small.
  
  

DVM Uses

• DVMs can measure voltages, current and resistance, so they are useful nearly anywhere. Automobile mechanics, electricians, electronics repair technicians and heating and cooling technicians all use DVMs regularly to make measurements and compare with expected values so they can understand how their equipment is functioning. DVMs are also useful for precision measurements of even thousandths of a volt, something that could not be done with most analog meters.
  
  

Comparing DVMs and Oscilloscopes

• For many purposes, a DVM is a sufficient and compact tool to measure voltages and diagnose problems. If the problem is more elusive, an oscilloscope can be used to watch a voltage and see if there are subtle changes. If the signal is a waveform such as audio, radio waves or a computer "clock," an oscilloscope is the favored tool of analysis because of the rapid changes.