How Do I Make Low-Current Measurements; Low-Current Connections - Keithley 2601A User Manual

Series 2600A System SourceMeter
Figure A-6
Model 2635A/2636A contact check connections
smua.reset()
smua.contact.speed = smua.CONTACT_FAST
smua.contact.threshold = 10
if (not smua.contact.check()) then
--One/both contact resistances are not
--below the programmed threshold.
smua.contact.speed = smua.CONTACT_SLOW
rhi, rlo = smua.contact.r()
print(rhi, rlo)
exit()
end
smua.source.output = smua.OUTPUT_ON

How do I make low-current measurements?

Low-current connections

Low-current measurements (<1μA) are subject to errors caused by leakage currents and leakage
resistances in the signal path For that reason, Models 2635A and 2636A are equipped with triax
connectors to minimize these problems. To assure accurate low-level measurements, the integrity
of the signal path must be maintained to the DUT, including using both low-noise triax cables and a
suitable test fixture.
Figure A-7
could be a low-current semiconductor device, a high-megohm resistor, or any other passive or
active electronic device requiring low-current measurements. Note that the DUT is enclosed in
2600AS-900-01 Rev. B / September 2008
®
Instruments User's Manual
shows typical connections for low-current measurements. The DUT in this example
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Appendix A: Frequently Asked Questions
-- Restore defaults.
-- Set speed to fast.
-- Set threshold to 10W.
-- Check contacts against threshold.
-- Set speed to slow.
-- Get resistance readings.
-- Return contact resistances to the
-- host.
-- Terminate execution.
-- Turn on output and continue.
A-9