Voltmeter Behavior, Verify Accuracy Options

[Superhawk996]

Starting a new thread in response to @emeryGT 350 comment in another thread as follow up

Here’s the background:

[emerygt350]

It is interesting how in both cases they behaved best at 12 volts but one was slow lower and the other misbehaved higher.

[Superhawk996]

It is interesting how in both cases they behaved best at 12 volts but one was slow lower and the other misbehaved higher.

The variance in damping isn’t terribly surprising. Assuming I’m right that they are using an RC circuit for damping, the tolerance of resistors would have been +/- 10% and capacitors could be 20% or more if there is an electrolytic capacitor in there. And that would be before 50 years of aging.

I think it’s a combination of what was said earlier - cheap gauge built to do a basic job at a an affordable price point.

However what has always been pretty clear to me is that the accuracy is pretty good. 0.5 volt +/- really is no big deal in the scheme of things.

Add in 50 year old aging wire harness with convoluted 12v+ sourced off the brake lamp circuit and you get the typical bounce as lights cycle on/off.

Let us know what you find with yours.

If I ever find one that is in-op, I’ll tear it down to verify what is being used for damping.