View Single Post
  #12  
Old 07-18-2005, 12:05 AM
Moneypit SEL's Avatar
Moneypit SEL Moneypit SEL is offline
Now what?
 
Join Date: Jun 2005
Location: SE PA
Posts: 525
Quote:
Originally Posted by dkveuro
Measurements below 3 Volts frequently involve sensitive circuits which have high output resistance. To measure them accurately, you want a DMM with at least 1000 MegOhms input impedance. Better DMMs automatically provide this high input impedance.
A thousand Megohms? That's a new one for me. What kind of accuracy difference is there between a 10M ohm and 1000M ohm in testing?

Quote:
Originally Posted by dkveuro
It'd be more convincing if it listed a lower impedence rather than not listing it at all. An internet blurb is hardly the entire Users Guide. As to the rest, I'm guessing that the meters with variable impedence aren't exactly the cheaper ones. I'm also guessing that a meter with 10M ohm impedence is accurate enough for the test in question. Or, have you seen a DMM with less than 10M ohm impedence?

In any case, it's good to have impedence information out where it might help somebody.
__________________
1989 300 SEL that mostly works, but needs TLC
Reply With Quote