30
Keysight M9602A/M9603A Startup Guide, Edition 3
Connecting a DUT
Guarding
Guarding reduces the leakage current between the instrument and a DUT. This is
important when you perform low current measurements.
The overview of the guard technique for the grounded measurement is shown in
. The guard shield is necessary to prevent the leakage current in the
measurement environment including extension cables, test fixtures, shielding
boxes. It is important to use a triaxial cable such as Keysight PX0102A-001 Low
noise triaxial cable (1.5 m). The buffer amplifier keeps the potential of the Guard
(inner shield of triaxial cable) at the same potential as the High force (core), so that
the current does not flow between the core and the inner shield. Therefore ideally,
the current measured by the instrument is the same as the current at the DUT
terminal because there is no leakage current. For several connection examples
such as the floating measurement, refer to the configuration guide.
Figure 1-4
Guard Technique for Grounded Measurement
Low force signal comes from the outer shield of the HF connector. In the ground
measurement, the outer shield of the triaxial connector must be electrically
isolated from the shield of your test fixture or shielding box. Do not connect the
outer shield to anything other than the low terminal of DUT.
Never connect the guard shield to any output, including the frame/chassis
ground or any other guard terminal. Doing so will damage the M9602A/M9603A.
A
DUT
x1
M9602A/M9603A
Low force (outer shield)
High force (core)
Guard (inner shiheld)
Guard shield
HF connector
Triaxial cable
Shield (chassis)
Insulator
Short bar
Содержание M9602A PXIe
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