73APT-100K-SR Series Resistor Kelvin Probe

The pitch is the spacing of the probes, measured inside edge to edge
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True Kelvin Probe Design with series resistor on one contact probe

True Kelvin connection, each probe is connected to one SSMC connector, the ground/guard is shared.
Requires only one micropositioner for 2 connections.
Low current design, (<10fA)
Excellent for use with LCR's, or applications that require sensitive probe resistance correction through instrument "sense" line.
A series resistor is connected between rear SSMC and probe contact (inquire for values).
Identical to the 73APT series-100K probe with a series resistor.


Less than 10 fA resolution.
Probe pitch (distance between probes) can be ordered from 12 to 100 um.
Very low parasitic capacitance design.

(*Specify radius, pitch and resistor value upon ordering)


 Also see: 


       74CJ-APT-KS Low Noise Coaxial Probe Holder with replaceable coax probes

74CJ-APT-KS-SR Low Noise Coaxial Probe Holder with replaceable coax probes & series resistor

73APT-100K Kelvin Probe

73APT-100K-SR Kelvin Probe with Series Resistor

76CPC-SSMC Coaxial Cables

76LPC-SSMC Low Noise Coaxial Cables

86LPC-SSMC Low Noise Triaxial Cable

Product Specifications:


Material: Type II Gold plated brass/copper Connectors: Two SSMC connectors, with each being connected to one of the two semi-rigid coaxial probes creating a True Kelvin connection.  The SSMC positioned furthest from the probe has a series resistor (SM-603 series - 1/16 watt) between the probe and connector mounted within the body.  The probe mounting shank is: 0.124" ~ 0.125".  The probes of the 73APT-100K are not replaceable due to the co-planarity issues with the Kelvin contact.  The typical probe contact co-planarity is within 3-5 microns.


Current leakage: < 10 fA. Frequency: > 150 MHz Capacitance (Guarded): < 10 fF Impedance: 50 Ohm Power Handling: > 125 Watts @ 18-21 Deg. C Voltage Rating: > 250 Volts RMS @ sea level


The 73APT-100K Kelvin Series probe can be ordered with custom configurations including:

  • Series resistors
  • Custom bends
  • Custom mounting shanks sizes and configuration
  • SMA connectors
  • Custom UT-047, Semi-rigid coaxial with BeCu core
  • Radii and pitch (pitch is the distance between the two probe tips at the radius)


73APT-100K True Kelvin Probe

 Please click on the photo to review the 73APT-100K PDF