Agilent Technologies B1500A Self-Paced Training Manual page 13

GSWU
SCUU
GSWU
The GSWU must be connected to the outer conductors of the manipulators/positioners
connected to the Force1/CMUH and Force2/CMUL connectors of the SCUU. And the GSWU
control cable must be connected between the GSWU and the SCUU.
When the SMU paths are available for the manipulators/positioners, the GSWU opens between
the outer conductors. However, when the MFCMU paths are available, the GSWU connects them
together to make the return path of measurement current. This will reduce the signal path
impedance. And this is effective for the accurate capacitance measurement.
By using the EasyEXPERT software, cable length between the CMU and the SCUU is
automatically detected, and the GSWU switch control is automatically performed. Also,
capacitance error compensation is also automatically performed if the compensation data are
available.
The GSWU is effective for
•reducing the residual inductance of the measurement cable
•stabilizing the residual inductance when measurement cable distance is changed (moved)
It's roughly 1/10 to 1/30 when used with two 80 cm cable.
Note:
When the SMU paths are available for the manipulators/positioners, the outer conductors must
be open because they must be connected to the SMU guard terminals that must be always open.
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