On 3/29/2009 4:50 PM Tony Hwang spake thus:

David Nebenzahl wrote:
On 3/29/2009 2:41 PM Jon Danniken spake thus:

"svu geek" wrote:

I need to buy a multimeter. I noticed that for the resistance some
have 2000k and some have 20M, which I believe are totally different.
Which one is better to have? Or does it even matter? I'm mostly
interested in testing something that's around 2M. So I don't know if
it matters which multimeter I get.

For resistance measurements, more is better. A short circuit is
ideally zero ohms, and it goes up from there.

Practically speaking, you might never need to measure more than 2
MegOhms, which is a high enough value for most uses.

You're confusing the *resistance* range of a meter to its *impedance*.
Both are measured in ohms. The impedance has nothing to do with how high
a resistance the meter will measure.

On digital meters input impedance is pretty high already. High Z gives
more accuracy by not loading circuit under measurement but some times it
is not useful for it's high sensitivity. That is why I still have old
tank Simpson 260, Fluke, and even an old VTVM when dealing wth high
frequency circuit. On top of that o'scope if I need to see something
when numbers don't help. Some times also simple test light is enough.

But we weren't talking about that aspect of meters, so you're just
further confusing the subject.


--
Made From Pears: Pretty good chance that the product is at least
mostly pears.
Made With Pears: Pretty good chance that pears will be detectable in
the product.
Contains Pears: One pear seed per multiple tons of product.

(with apologies to Dorothy L. Sayers)