I want to measure the voltage across a resistor in my circuit. The circuit is battery powered. I don't want to use the two probe method and calculate A-B to get the results. Can I use one probe to measure the differential voltage as shown in the figure below? No other point in the circuit is connected to the oscilloscope GND except one of the test points.

enter image description here

  • 1
    \$\begingroup\$ youtube search for "how not to blow up your oscilloscope". While one could easily answer this as yes or no, you should really inform yourself to answer it yourself, so that you can do it in the future \$\endgroup\$
    – PlasmaHH
    May 23, 2018 at 21:01
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    \$\begingroup\$ No USB, no audio connection, no debugger connected, nothing? No other path from anywhere on the DUT to earth ground through another cable or piece of hardware? \$\endgroup\$
    – user57037
    May 23, 2018 at 21:10
  • \$\begingroup\$ There is no other connection to earth ground, no USB, no audio, no debugger connected, no connection to PC/laptop \$\endgroup\$ May 23, 2018 at 21:16
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    \$\begingroup\$ Of course you can. Floating also means that you don't have any capacitive current leaks. \$\endgroup\$
    – Dorian
    May 23, 2018 at 22:16
  • \$\begingroup\$ Thank you Dorian. Is there any measurement error if I use this technique instead of two probe method? \$\endgroup\$ May 24, 2018 at 19:07

1 Answer 1


Looks like you are trying to measure current. A single ended probe would work only work if the resistor was also connected to ground.

Info on low side power measurements: http://www.electronicdesign.com/power/what-s-difference-between-high-side-and-low-side-current-sensing


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