Freaky Amazing DMM?!

"HI-Z"

...and electricians who know nothing about electricity, perhaps.

"HI-Z"

has

But at least smart enough to chose the right tool for the job.

Dave.

or "HI-Z"

has

bit

will

For an electrician who know nothing about electricity (99.44% of them, apparently), or if that's all one is ever going to do with the meter, perhaps. For anyone who knows anything about electricity or wants a tool that has more than one use, the high impedance meter is a better choice.

Totally useless in areas of high RF.

As the man says, the proper tool for the job

In article , snipped-for-privacy@argonet.co.uk says...>

Wrong.

Know what you're doing is a better solution. Loose nuts are dangerous.

That statement simply exposes another large hole in your knowledge and experience.

I spent 20 years on a high power HF transmitting station - believe me - I

I would agree. Take two meters. One is 1Kohms. The other is 1Gohms. If the load is low impedance, say 100 ohms, then there's an appreciable error with the low impedance meter-- simple ohms law. While the error associate with the high impedance meter is unmeasurable.

People are probably confusing the fact that a high impedance meter while unconnected to anything will pick up signals, for obvious reasons.

Paul

In article , snipped-for-privacy@argonet.co.uk says...>

Wrong again, in so many ways, but you're good at that. If your field strength is enough to saturate the innards there isn't much that can be done. A low impedance meter isn't going to help. OTOH, we weren't talking about probing inside a microwave oven in operation, rather power distribution panel.

Evidently you don't know much.

Or make the one you have work. It does take some knowledge of basic electricity, but evidently that lets a lot out here.

Sorry, I didn't pay much attention who I was replying to. I'm not taking sides, but I am saying that high impedance meters are better.

Paul

- I

Right. It's easy to lower the effective impedance of a high=20 impedance meter. Going the other way is a lot harder.

Doesn't need to get into the innards directly, you can screen that, but you've got a pair of leads forming an aerial and most likely a diode at the junction of the test lead and the DVM socket. A low impedance input attenuator will load that down to something insignificant compared with what you are measuring.

Late at night, by candle light, "David L. Jones" penned this immortal opus:

"HI-Z"

The circuits are loaded, so any bad contacts will certainly affect the reading. Which is the way I like it. Any funny readings, move up to the next point in the line and check there.

I do know better than to measure an unloaded line without sticking some suitable load across it.

Anyways, AIUI, this started with a meter with Hi-Z in the mV range, most DVMs use a 10M or 1M divider at higher ranges.

- YD.

In article , snipped-for-privacy@argonet.co.uk says...>

Nonsense. There are many things that can be done to eliminate any external factors. Add a shunt resistor and you have your low impedance meter.

Nonsense. If an input resistor will load down your circuit so will your low impedance meter. It's *exactly* the same thing, except the user gets the choice.

Go get some practical experience.

In article , snipped-for-privacy@argonet.co.uk says...>

I certainly have more than you.

r*

-Z"

This is an oft used but seldom understood saying. The reason a craftsman supposedly never blames his tools is because a craftsman tends to buy quality tools in the first place.

claims *over*

or "HI-Z"

Keithley has

a bit

will

what

Yes, electricians generally just do just the one similar job. That's why they make meters designed for just such specific purposes. Giving your average electrician say a Fluke 289 is a bit overkill and would likely not be as productive as a more job specific instrument.

That's why many good meters have selectable Low-Z and High-Z modes.

Dave.

Safely, in a dangerous situation? What part of using the right tool for the job don't you understand?

Yes, High-Z meters are good (more useful in more cases), but Low-Z meters have their place too. There simply isn't any argument here, if you need a Low-Z meter, use one. If you need a High-Z meter, use one. "Making do" without the right tool in serious situations is stupid.

Agreed. That's why if you have serious needs you either have a dual purpose meter, with Low-Z and High-Z modes, or you have two meters.

Dave.

Daniel wrote in news:e8f56b53-9c0c-49cd-b6b5- snipped-for-privacy@i24g2000prf.googlegroups.com:

I thought it was to do with a craftsman knowing the limits of his tools, thus not blaming them for over-reaching.

Related to that, I find the best definition of a toolmaker is one who achieves greater accuracy than was provided, and makes a system to easily repeat that gain.