The Aplab’s ADP311 is an active differential oscilloscope probe. The differential techniques employed, permits measurement to be taken from two points in a circuit without reference to the ground. This allows oscilloscope to be safely grounded without the use of opto Isolators or Isolating transformers. The two signals are processed in the probe and the resultant output is feed to the single channel of oscilloscope. Thus reducing the errors normally, associated with two separate probes and oscilloscope amplifier.