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Tektronix dpo4104

  1. Sep 1, 2015 #1
    how do i measure two (or more...) signals at once?

    i mean, when i try to measure two signals (with difrrent frequecies) with two difrrent probes, i get one good signal (almost clean...) and the other one, is look very dirty...

    thank you!
  2. jcsd
  3. Sep 1, 2015 #2


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    Science Advisor
    Gold Member

    I am not sure what you mean. The oscilloscope can only trigger on one channel at a time. meaning you can't measure two channels independently. Hence. if the two signals you are trying to measure have no relation to each other it is difficult to measure both (you might still be able to use the scope as a digitizer).

    That said, this is very rarely a problem if you are measuring on a single circuit, unless of course you really have two signals with no fixed relationship?
  4. Sep 1, 2015 #3
    i understand...

    the two probes are not related (two difrent circuits...).

    thank you :)
  5. Sep 1, 2015 #4
    This seems to be a triggering problem (or feature).

    The scope trigger determines when the machine starts to draw the line. There are a number of options depending on your scope. Most scopes have one trigger for all the channels (with several methods of selecting when it activates). Most people want to know what is happening on the various channels at the same time. This means two channels at random frequencies don't play well together. Yet it allows us to see if one frequency is synchronized with the other (perhaps at an harmonic).

    Read up on triggering and triggering options. Your scope may or may not support a solution to this dual trigger problem. What make and model is your scope?

    You can always plot (or take a picture) with the trigger on one channel, then switch the trigger to the other and do it again.
  6. Sep 1, 2015 #5
    tektronix dpo 4104bl
  7. Sep 1, 2015 #6


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    Just use the "Single-Shot" trigger to capture both waveforms at once on the screen. You can then do all of your measurements on each waveform separately using the cursor measurement options. :smile:
  8. Sep 1, 2015 #7
    thank you! :) :) :)
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