Technical data
Module 8
Capacitance Measurement
8-16
Hc
Hp
Lp
Lc
CMU cable or 
SCUU cable
Extension cable
CMU
Manipulator 
or Positioner
DUT
4TP configuration
Shielded 2T 
configuration
3T configuration
Return path
GSWU
– for Accurate Capacitance Measurement
This slide shows the typical cable connections for the capacitance measurement. Note the following 
tips to perform the measurement accurately.
-Extend the four terminal pair configuration as close as possible to the device side
-Make the return path at the end of the extension cables (coaxial cables)
The return path is effective for:
-reducing the residual inductance of the measurement cable
-stabilizing the residual inductance when measurement cable distance is changed (moved)
The residual inductance will be roughly 1/10 to 1/30 compared with no return path.
To make the return path, use the GSWU (Guard Switch Unit) which was developed to make the 
setup easily. The GSWU is the accessory available only for the B1500A equipped with the CMU 
and the SCUU. 
Note:
For the accurate measurement, it is recommended to make the return path at the point as close as 
possible to the device side.










