GSM-20H10 User Manual
37
2-wire local
sensing
2-wire local sense connections can only be used if the
deviation contributed by test lead IR drop is
acceptable to the user. When current levels below
100mA, the errors are usually not significant
(assuming test lead resistor is not greater than 1Ω).
Since the current in the series circuit is the same at all
points in the loop, 4-wire sensing cannot improve the
accuracy of I source or current measurement.
Therefore, if it is I source measuring current mode,
you can use 2-wire sensing. Other conditions that
allow the use of 2-wire sensing methods include:
• Test circuit impedance is 1kΩ. Above 1GΩ, Guard
option should select Cable.
• Measure V function or measure I function.
Sense And Guard Selections
Sense
selection
When using the SENSE HI and LO terminals of the
GSM, 4-wire remote sensing must be selected. When not
using these terminals, 2-wire local sensing must be
selected.
NOTE: When Sense mode or Guard settings are
changed, the OUTPUT will turn off.The GSM defaults
to the 2-wire mode when the output is off, regardless
of the sense setting. When the output is turned on, the
present sense setting will be in effect.
