how critical is it, that resistors of 1 megohm value markings, measure that value
I have an old R2R set that all the resistors measure OK in, except for (2) of the 1M-ohm values
can a small Fluke digital multimeter measure that high a resistance accurately, with the 9v battery inside ?
It depends on the application, but your reading could easily be off if you're measuring the resistors without removing them from the circuit. The circuit could have a parallel resistance that brings the measured value down lower.
Most DVM's worth anything can measure over 1M-ohm, and most Fluke DVM's are worth something. And if it couldn't measure 1M, the display would indicate an open circuit, rather than report a value that is incorrect.
You would need to remove the resistors from the circuit in order to get a meaningful measurement. And, for a dollar you could get some 1M resistors from Radio Shack (if you're in the USA) if it turns out you need to replace them.
Regards,
Mark
p.s. this would have been more appropriate for sci.electronics.basics
If you mean an R:2R DAC network, the LSB-end resistors are sometimes half the normal values.
John
If he gets this unit fixed, it will appear as SPAM on these groups.
Yes - no problem.
However, when measuring high value resistors be sure that your body is not part of the circuit being measured. If you use your fingers to hold the resistor leads against the probe tips, your body resistance will be enough to bring the indicated value down from 1 meg to 500 K or less.
If you are measuring the component while it is soldered into a board, there maybe other components in parallel with it that cause a lower-than-expected reading.
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Good call. Even "coffee breath" is enough to alter high value resistors. Especially at higher voltage excitations.
Don't help this eBay con artist and spammer, Charles M. Nudo, Jr., of Drums, PA, "66-catalina" on eBay. He is one of the worst eBay spammers ever to hit Usenet via Google Groups, which has already banned 28 of his accounts for spamming, threats of violence, divulging personal information and the like.
Take his spam-gram, copy including header, and forward to his ISP, Frontier.net, adding "SPAM FROM YOUR SUBSCRIBER" to the fwd title, to:
snipped-for-privacy@frontiernet.net
Also, cc:
snipped-for-privacy@google.com
So far, 28 of his Google Groups accounts, as well as two of his AIOE accounts, have been terminated for spam. Let's clean him out for good!
Up to 100 Megs, with 1% (as a guess without knowing model and/or specs) accuracy. Are you sure that other resistors are *not* in parallel with the "suspect" resistors?
I never see the spammers, but I always see your spam reply.
plonk....
JeffM wrote:
The Real Andy wrote:
Seems like you're all mouth and no action. news: snipped-for-privacy@4ax.com
...or are you just incompetent? There a lot of people that don't want to see spam-related stuff. THEY configure their newsreaders as such and I make it easy for them to weed out this stuff.
Too bad you only have half a brain.
good post- DeserTBob has established himself as the urinal piss-bubble foam of Usenet, killfile is the remedy for him
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