advantagesand disadvantages of digital voltmeters over the analogue voltmeter?

Answer 1

Today, the digital voltmeter is probably the best bet for most purposes. It has a high input impedance, meaning that it will load circuits less and provide a more accurate reading for in-cirucit testing. It has a high frequence response for AC measurements. The types of measurements that can be done are astounding. For testing diodes and transistors, it can give the voltage drop across the junction. Some have built-in transistor testers, frequency counters, and even oscilloscopes.

On the other hand, they do require a functioning battery to operate, and an analog voltmenter does not. If the battery on an analog multimeter fails, one can still use it for voltage measurements.

The previous post mentioning the digital multimeter's 9 volt battery damaging diodes was incorrect. The low current used in the ohms position is actually insufficient to properly bias the diode for an accurate check. That is why DMM's have a diode position.

Answer 2

A digital voltmeter has a higher input impedance, and is more sensitive than an analog meter. It can be read much more accurately, to four digits or more. Some DVMs are autoranging. Other DVMs can interface with other equipment or a computer for automated testing and data logging. In a nutshell, they can be extremely versatile.

Sometimes an analog voltmeter will give a better feel for what is happening in a circuit. One example is the problem of measuring an audio signal, which is constantly changing. A DVM will jump around and it's impossible to get a reading. However, the momentum in the movement of an analog voltmeter will average the voltage, and give a more useful indication of the signal level.

Answer 3

The digital voltmeter is almost always more accurate, plus there is no additional inaccuracy caused by looking at it from an angle. But analog meters do have one advantage: They are better at showing the rate of change of voltage with respect to time, which is useful when capacitance is involved.

Answer 4

It's almost impossible to follow the trend of a slowly varying voltage (or other parameter) on a digital meter. The digits simply change quickly and you can't tell what's happening.

But on a good quality analog ( not analogue) meter, you can watch the needle swing gradually one way or the other. Digital meters have very fast response times, and will show an reading almost instantly.

4 JAN 07, 0533 hrs, GMT.

Answer 5

I have and use both, for different purposes, but mostly I use the digital meter (which I paid $3 for at Harbor Freight Tools -- a remarkable bargain). For examining circuits containing diodes, the analog meter is more useful, as the 9 volts used on the high range will drive current through a diode. The digital meter is more precise, and may be more accurate as well.

Answer 6

Response time of inexpensive digital meters can be a problem. Higher end meters are adjustable. Analog meters are subject to break with abuse. Analog meters are easier to read at a distance. The movement of the needle is easier to understand than a bunch of numbers flashing on the screen. Digital meters are more complicated and can do more, but for normal uses these extra features are not needed. Which one to chose will depend on what you intend on doing with it. I have a cheap Radio Shack analog meter that does all I want it to do.