Analog Voltmeter Vs. Digital Voltmeter

Digital voltmeters display results on a LCD screen.

Voltmeters measure the amount of voltage passing through a circuit. Analog and digital voltmeters differ in how results are displayed, in level of internal resistance and accuracy. Digital voltmeters are now the most commonly used.

Display

Analog voltmeters employ a needle to display readings.

Obvious differences between analog and digital voltmeters lie in how results are communicated. Analog voltmeters give readings by moving a needle across a printed background of possible results. Digital voltmeters electronically display results on a LCD screen.

Impedence

Digital voltmeters operate on a fixed level of resistance, usually around 10 million ohms. Analog voltmeters can offer resistance as low as 10,000 ohms. An ideal voltmeter would provide an infinite amount of impedance. Such voltmeters do not exist.

Accuracy

Because of the high resistance level of digital voltmeters, they give a more accurate reading, especially at higher voltages. Lower resistance levels in voltmeters can give false readings if the resistance is low enough to increase the circuit's current.

References

• Analog and Digital Voltmeters
• Voltmeters
• Basic Electrical Principles

Resources

• Potentionmetric Voltmeter