Offset; Cable Noise - Keysight B2980B Series User Manual

create contaminating condensation that, in turn, can lead to a serious degradation
in the insulation performance. You must control the temperature and humidity in
the measurement environment appropriately.

Offset

The ideal measurement instrument shows no current flow when nothing is
connected to the measurement terminals and no voltage is being applied.
However, in a real-world measurement environment, an instrument will have a
certain amount of offset current. The offset current can be reduced by using the
offset cancel function and so on.

Cable Noise

Cable noise can be caused in two ways: by the triboelectric effect and by the
piezoelectric effect. The triboelectric effect is the result of friction caused by
motion at the boundary between the conductor and the insulator. The
piezoelectric effect is the result of mechanical stress applied to the insulator.
Current from both of these effects can negatively influence low current
measurements.
Generally, using the low noise coaxial cable can reduce the noise caused by
vibration. Also fixing the cable is effective for preventing it from vibration. Note
that applying too much stress to the cable or bending it tightly will have a
detrimental effect on the measurements.
Keysight B2980B User's Guide, Edition 1
Mechanical stress
Measurement cable
Outer shield
How to Perform Measurement
Measurement Considerations
Frictional motion at boundary
Outer jacket
127