Yes.

Yes

And nowhere (in my limited experience) will one find the distinction as clearly as in avionics. The first thing we start teaching engineers as they come in the door is *Ground ain't ground.*

(Or I am being a snob, and it is just one area in which the differences are obvious and most familiar to me.)

But we use several grounds so one knows what the potential differences *might* be under different circumstances.

Chassis Ground - is simply leached away through the airframe, frequently impacted by maintenance practices and age issues. Also most likely to *float* from outside sources like P-static.

Power Ground - isolated from else, and with higher sink needs. Frequently routed back to negative of producing source.

Signal Ground - cleanest ground available, but with limited need for capacity. Frequently routed back to battery negative.

As much as I hate to say anything good about EEs (I'll never forgive the $$%#**& for killing 8-track), they solved this long ago with earth, chasis, and signal ground. They even use different symbols.

Ah yes, 8-track tapes. The one consumer recording medium designed to fail with use. Somebody in the RIAA legal department must've loved this platform.

You've missed one of my points. Just because somebody knows something doesn't mean everyone remembers this all of the time. None the less you do bring up a point I forgot to bring up. The IEEE recognizes at least three different symbols commonly called "ground". They did this for a reason.

I opened this discussion to hear other peoples experiences in this.

"I opened this discussion to hear other peoples experiences in this."

The last experience was an electrician who was of the "ground is ground the world around" school of thought.

We are still debugging all the ground loop problems in the plant (4 years later).

Sorry, I was being too flip. I understand your point, but there is just so much legacy (all those IEEE standards, harmonized standards throughout the world, and so on) that it would be a huge, huge undertaking, requiring perhaps several decades. Our present system actually does work well if people only learn it and follow it. There is no magic to grounds below several MHz, and they can be made to do pretty much what we want.

I have seen grounds royally screwed up a lot. But, I've also seen them done very well when people knew what the heck they were doing. That seems to me to be the path to take.

The same case stands for good old ohms law, sure they are both technically oversimplifications BUT they do work for 99 percent of the time. The trick is to know when to use the simple one and (in the case of high frequency) when you need to use the more complex one and all the additional design rules they require you to really consider (least your ground become an unintended antenna or heater).

No use over designing something after all (yes I said it, and yes I am a REAL Engineer).