K
krw
Guest
On Tue, 20 Jan 2009 21:50:16 -0800, JosephKK <quiettechblue@yahoo.com>
wrote:
wrote:
Metallic?On Tue, 20 Jan 2009 19:22:00 -0600, krw <krw@att.bizzzzzzzzzzz> wrote:
On Tue, 20 Jan 2009 22:05:27 -0300, YD <ydtechHAT@techie.com> wrote:
Late at night, by candle light, Arlowe <bare.arsed@gmail.com> penned
this immortal opus:
krw used his keyboard to write :
In article <mn.a5307d9188b78d0d.90583@gmail.com>,
bare.arsed@gmail.com says...
krw explained on 19/01/2009 :
On Sun, 18 Jan 2009 19:35:00 +1100, Arlowe <bare.arsed@gmail.com
wrote:
on 16/01/2009, Paul supposed :
On Jan 15, 2:19 pm, "David L. Jones" <altz...@gmail.com> wrote:
"Paul" <energymo...@gmail.com> wrote in message
news:54c2d7cf-c506-4647-b272-17d608c8854a@x8g2000yqk.googlegroups.com...
I'm testing a new DMM I purchased, AM-240 by Amprobe. It claims *over*
100Mohm impedance in 400.0mV mode.
Nothing new there, many DMM's have selectable "high impedance" or "HI-Z"
modes on the mV range. e.g. the Fluke 87.
I've looked at the specs of ~ 30 DMM's today, include a lot of
fluke's, and never seen anything near 14Gohms impedance. Keithley has
an electrometer that's probably higher. Most DMM's are around 10Mohms
(not gigaohms) input impedance. Don't you think 14 gigaohms is a bit
high?
PL
The evil thing about Voltmeters with very high impedance is they will
read induced voltages that analog meters wouldn't.
It makes a voltmeter useless for checking for live circuits in a
crowded panel.
A craftsman never blames tools for his failures. Hackers, on the
other hand...
If you work with electricity you had better know the limitations of
your tools or you will find them...the hard way.
That is certainly true (though perhaps your heirs are the ones who
will find you), but doesn't modify my statement. In this case, the
tool *can* be used as long as the one using it knows what he's
doing.
Ok....everything seems to pass right over your head....
I pointed out a limitation of a DMM and you seem to be inferring that I
am somehow a hack who blames his tools...
BTW> I am not a "craftsman" I am an electrcian..
You don't do what I do for as many years as I have without knowing what
the fuck you are doing.
What's wrong with using a hi Z voltmeter in a live panel? I do it more
often than I really care for, and never have a problem.
There isn't anything wrong with it. Analog meters are dead. High
impedance digital meters are only a problem if there is a loose nut
inside the panel, holding the leads.
I noted the lack of distinction between animate and metallic nuts.