Keithley 2450 Reference Manual page 51

Section 2: General operation
Setting
Measure range
Sense Mode
Auto Range Low
Limit
Limits
Auto Zero
NPLCs
Offset Comp
2-24
Model 2450 Interactive SourceMeter® Instrument Reference Manual
Figure 17: Model 2450 function indicator
Description
Set the measurement range for the presently selected
measurement function. You can only select a measurement range
if you are sourcing one type of measurement and measuring
another.
Select 2-wire (local) or 4-wire (remote) sense mode. Use 2-wire
sense if the error contributed by test lead IR drop is acceptable.
For more accurate voltage source and measurement accuracy, use
4-wire sense mode.
Set the Auto Range Low Limit to prevent the instrument from
selecting a range that is lower than appropriate for your application.
Select the button next to Limits to open a menu of limit settings.
You can set two separate sets of limit settings (Limit 1 and Limit 2).
For each set of limits, you can turn the limit state off or on, turn the
Auto Clear function off or on, and set the low and high limit values.
Set Auto Zero to On to set the instrument so that it periodically gets
new measurements of its internal ground and voltage reference.
This setting increases measurement accuracy, but may slow
measurement time.
Set the amount of time that the input signal is measured. Lower
NPLC settings result in faster reading rates, but increased noise.
Higher NPLC settings result in lower reading noise, but slower
reading rates.
The offset compensation setting is only available when the
instrument is set to measure resistance (SVMR(Ω) or SIMV(Ω)).
Turn this setting on to improve low-resistance measurement
accuracy.
2450-901-01 Rev. B/September 2013