Comparing the Accuracy of Analog vs. Digital Multimeter

Is there any way to compare the accuracy of an analog multimeter to a digital multimeter? I would hope the digital is more accurate, but how can you prove it?

Analog Meter Accuracy:
R X 1 -- 2.5 degreees of arc
R X 100 -- 2 degrees of arc
R X 10,000 -- 2 degrees of arc

Digital Meter Accuracy: +(0.9% + 1)

I'm looking at resistance only.

Re: Comparing accuracy of analog versus digital multimeter

RCW said:

Is there any way to compare the accuracy of an analog multimeter to a digital multimeter? I would hope the digital is more accurate, but how can you prove it?

Analog Meter Accuracy:
R X 1 -- 2.5 degreees of arc
R X 100 -- 2 degrees of arc
R X 10,000 -- 2 degrees of arc

Digital Meter Accuracy: +(0.9% + 1)

I'm looking at resistance only.

Click to expand...

we need more info.

What is the total arc of the analog meter?
Is the digital meter auto ranging?
Is 0.9% error of full scale read out?
What are the read-out ranges on the digital?

Of course with the analog meter, there is also parallax error.

Re: Comparing accuracy of analog versus digital multimeter

That's kind of an open-ended question. If the question is generically which is more accurate, I'd say there is no answer. It's kind of analogous to wondering whether a car or truck is faster (that's the best analogy I can come up with for the moment).

There are probably some analogue meters that are more accurate than some digital meters. Some of the mirrored movements on the best analogue meters minimize parallax error. There are perhaps some of the best quality analogue meters that are more accurate than some of the worst digitals.

Some of the limiters on analogues are:
-lower input impedance (loading effect)
-parallax error (as already mentioned in earlier post)
-tilt errors (tilting meter causes errors in varying amounts)
-operator visual interpretation errors (user makes errors in how they
interpret readings).
-movement slop and hysteresis

One of the advantages of old analogues (such as a Simpson 260 Series) is the use of a D Cell to drive the resistance function (higher current capacity). I've heard feedback from technicians who love it because it is much more effective in taking front to back resistance readings in transistors/diodes/etc.

Just a few thoughts.

If we intent to study on measurement accuracy, we should have a standard to refer to. Beside that, we also need to consider on how the traceability of the standard.

For resolution, thumb of rule is 10:1. Digital measurement would always has better resolution compared to the analog measurement system.

Sometime we always confuse on the term between resolution and accuracy.

Background on my question:
I recently went through a process audit by one of my customers. The process was cable wiring and this is to be performed using our customer's process specifications. One of the steps of the process is to verify the continuity of the wiring (i.e. point-to-point check). I was using a Fluke 12 DMM to do this. The customer's process spec did not specifically call this meter out in their list of equipment to use so I was written up for the process deviation.

The process spec does call out the use of a Simpson Model 260 multimeter or equivalent. I spoke to one of the engineers from the company that audited me. He suggested addressing the finding by showing the Fluke 12 is more accurate than the Simpson Model 260, therefore it is equivalent and beyond.

This is what I need to accomplish yet when I compare the two meter specs, it's like comparing apples and oranges.


Simpson Model 260 information -->> http://simpson260.com/downloads/downloads.htm
Fluke 12 information -->> http://us.fluke.com/usen/products/Fluke+12.htm?catalog_name=FlukeUnitedStates

We know that the resolution that you read on the gage is only one factor in gage error. Yes, rule of thumb 10:1 is good, but the overall benefit of digital generally comes from less reading errors and faster reading than it does from accuracy - which can be exactly the same. The true judge of which gage is best for a job is Gage R&R, not just accuracy and certainly not resolution. Perform that study on each gage, and see which one performs the best.

RCW said:

Background on my question:
I recently went through a process audit by one of my customers. The process was cable wiring and this is to be performed using our customer's process specifications. One of the steps of the process is to verify the continuity of the wiring (i.e. point-to-point check). I was using a Fluke 12 DMM to do this. The customer's process spec did not specifically call this meter out in their list of equipment to use so I was written up for the process deviation.

The process spec does call out the use of a Simpson Model 260 multimeter or equivalent. I spoke to one of the engineers from the company that audited me. He suggested addressing the finding by showing the Fluke 12 is more accurate than the Simpson Model 260, therefore it is equivalent and beyond.

This is what I need to accomplish yet when I compare the two meter specs, it's like comparing apples and oranges.


Simpson Model 260 information -->> http://simpson260.com/downloads/downloads.htm
Fluke 12 information -->> http://us.fluke.com/usen/products/Fluke+12.htm?catalog_name=FlukeUnitedStates

Click to expand...

If you're doing just a continuity check (i.e., verifying an electrical path between two points) it doesn't matter. On the other hand, if impedance is the issue they should say so, because when you check impedance of a path you're also verifying continuity. If they're concerned about impedance, they should have given you a nominal and tolerance. This is where the accuracy of the meter comes in, and you should be able to demonstrate equivalence by comparing manufacturers' specifications and demonstrate that the meter is properly calibrated.