Galvanically isolated voltage probes separate the device under test (DUT) from the oscilloscope and earth ground, enabling safer and more accurate measurements. This isolation effectively rejects common-mode signals, minimizes noise interference, and eliminates ground loops in high-voltage environments. A high common-mode rejection ratio (CMRR) is essential for capturing small signals accurately, even in the presence of large common-mode voltages at floating nodes. The CMRR of an isolated probe can be over 100 million times greater than that of a standard differential voltage probe referenced to earth ground. The CMRRs of Keysight's isolated probes are driven by the attached probe tip.
