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:

[rjames]

emerygt350 might just have a bad gauge. Mine gave inconsistent readings, started reading ~5 volts under, then later 10 under, and then ultimately nothing. Tapping it once in a while would bring it back to life, but eventually it completely died.

[Superhawk996]

emerygt350 might just have a bad gauge. Mine gave inconsistent readings, started reading ~5 volts under, then later 10 under, and then ultimately nothing. Tapping it once in a while would bring it back to life, but eventually it completely died.

Anyone have one opened up?

I’d be curious to verify what’s doing the damping. I’m assuming it’s just a little ceramic disc capacitor via RC circuit.

However based on how this one gauge will linger at 16v position while the other doesn’t (as long) I suspect there is some difference in capacitance and/or resistor values between my two gauges.

[emerygt350]

emerygt350 might just have a bad gauge. Mine gave inconsistent readings, started reading ~5 volts under, then later 10 under, and then ultimately nothing. Tapping it once in a while would bring it back to life, but eventually it completely died.

Anyone have one opened up?

I’d be curious to verify what’s doing the damping. I’m assuming it’s just a little ceramic disc capacitor via RC circuit.

However based on how this one gauge will linger at 16v position while the other doesn’t (as long) I suspect there is some difference in capacitance and/or resistor values between my two gauges.

That is really interesting. The way it sat at 16...

[Superhawk996]

emerygt350 might just have a bad gauge. Mine gave inconsistent readings, started reading ~5 volts under, then later 10 under, and then ultimately nothing. Tapping it once in a while would bring it back to life, but eventually it completely died.

Anyone have one opened up?

I’d be curious to verify what’s doing the damping. I’m assuming it’s just a little ceramic disc capacitor via RC circuit.

However based on how this one gauge will linger at 16v position while the other doesn’t (as long) I suspect there is some difference in capacitance and/or resistor values between my two gauges.

That is really interesting. The way it sat at 16...

Would be totally consistent with an RC charging constant that takes time both to build up - which will happen more slowly at low voltage and will take longer to bleed off at high voltage

I’ll try to get another video of the other gauge up later so you can see the difference between the two.

The absolute worst case is that it gets mechanically “stuck” up there after being driven to full scale but I don’t think so based on how consistently it releases.