Comparing Polar grounded and groundless differential probes
Application Note AP8510 

Comparing Polar grounded and fixed and variable pitch groundless differential probes

Polar groundless differential probes are especially designed for on board test of differential traces where direct access to the ground plane is difficult or impossible. Polar proprietary probe technology enables groundless differential probes to be connected via a single coaxial cable, providing reduced operator fatigue and lower cost of ownership.

Polar groundless differential probes are available as both fixed pitch and variable pitch to accommodate a wide variety of footprints. This note illustrates the excellent correspondence between the grounded and fixed and variable pitch groundless probe varieties.


Testing was performed on a coupon comprising a 100 ohm differential trace using three Polar probes:

  • Polar IPDS100 differential probe
  • Polar GDPS100 fixed pitch probe
  • Polar GDPS100 variable pitch probe

The resulting screen shots from the CITS880s show good correspondence between the three probe types and are shown below.

Note that the settings for probe length and test limits in the CITS880s test editor must be set appropriately for each probe type.

IPDS100 probe


GDPS100 fixed pitch probe

GDPS100 variable pitch probe

Polar impedance test probes

This note illustrates the good correlation between readings using three models of Polar PCB impedance test probes. These handheld probes are designed for use with the Polar CITS880s controlled impedance test system for on board or coupon based controlled impedance test.

Polar produces a comprehensive range of robust, ESD safe, handheld impedance test probes designed for production use in the PCB fabrication environment, ranging from the economical IPE series through the premium, short trace IPS series with coaxial internal structure for best signal integrity.