Which is more accurate Digital or Analog Meters?

[ggunn]

Precisely for this reason in addition to the digital display many digital meters incorporate an analog, segmented LCD bar readout so the observer can quickly glance to see where the reading is in the range of the full scale.

But it is still digital, is it not? The fact that it uses the digital data to encode an analog type readout doesn't make it an analog meter; at the heart of it there is still an A/D sampler. Each segment of that readout is either on or off.

 

[SparkyEngineer]

I would say digital can be more accurate (eliminates parallax, etc.), but the analog is better for troubleshooting as you can watch the needle and the response time is generally quicker (no calculations having to happen).

 

[weressl]

I would say digital can be more accurate (eliminates parallax, etc.), but the analog is better for troubleshooting as you can watch the needle and the response time is generally quicker (no calculations having to happen).

Not true, analog meters do use mechanical dampening and the 'calculations' happen faster than the blink of the eye, however digital meters use averaging/sampling to have a readable number to mimic the mechanical dampening of analog meters.

 

[kwired]

We must remember there is a difference between accuracy and response time of the display or indicator.

When measuring things that happen in less than a second our eyes are not able to pick up every detail anyway unless using a device that shows the measured value graphed over a time period, like an oscilloscope does.

 

[gndrod]

Which is more accurate Digital or Analog Meters?

Accuracy including temperature discrimination can be in favor of analog when the meter is in a sun environment. A glare from a chip reflection is somewhat challenging for readout and the LCD can turn black in extended sun exposures.

 

[PetrosA]

As others have written:

Accuracy is a range within certain parameters in relation to a known value. Every meter has conditions in which it will be more accurate than others, and usually what's called "calibration" checks the meter's performance at certain points along the scale (3V, 30V, 300V etc.) under controlled conditions to see if it's within spec. This is actually also checking repeatability - a meter that will always give you the same reading will be more dependable than one that's all over the place with its readings. Precision is another thing altogether, and is kind of like the difference between using a magnifying glass or a microscope - both will show you a larger image than you can see with your eyes, but the microscope will show more detail than the magnifying glass.

So let's say you want to check voltage drop with your meter. You check at point A and read 122.8V and at point B you get 126.4V. If your meter has good repeatability, you know that you have a 3.6V drop between points A and B. It really doesn't matter whether the voltage readings were correct or not as long as the difference between them is accurate.

Now you repeat the same test with two guys using two meters. If the two meters are close in accuracy (which you can check by testing the voltage at one point at the same time) then you can confidently calculate the voltage drop by doing the math. If they're not reading the same, but have proven repeatability, you can still do the math using an offset and be confident in the result.

If you have a cheap meter that has bad repeatability, you can't confidently do the test either way since you can't trust the readings from one moment to the next.

Precision (counts) will show you more exactly how big the difference is between the readings (ex. 3.589V vs. 3.6V).

So ultimately, repeatability or stability of the readings is the most important characteristic of any multimeter. As Zog mentioned, analog meters have to be calibrated semi-annually, which indicates that their repeatability is lower than a good digital meter. Many of the really good meters from Fluke, Dranetz (Gossen-Metrawatt) and possibly Agilent (they're new to the handheld market, so kinda too soon to say...) have shown that they read consistently over many years and calibration is only needed to verify that. Most of the other meters on the market are rebadged Asian units and your mileage may vary.