The 100D is an electric field probe, unlike the 100A/B/C. It has the best spatial resolution of all the probes. However, because it is an electric field probe, it does not offer the common-mode rejection that the magnetic field probes have.
The 100 series EMC probes are designed for identifying and fixing EMC problems. The 100A, 100B, and 100C are loop probes and are sensitive to magnetic fields. The 100D is a stub probe and is sensitive to electric fields.
The loop probes have integrated electrostatic shields, providing isolation from common-mode signals. As a result, these probes deliver excellent repeatability. The different loop sizes allow the user to select the optimum probe for a given frequency, providing the optimum sensitivity and spatial resolution.
The 100D stub probe, with its narrow tip, offers the highest spatial resolution. It is ideally suited to tasks such as tracking EMC sources down to the individual pins of an IC.
Because of the planar construction of the probes, even the large loops are only 0.11” thick, allowing the probe to be inserted into narrow seams and gaps.