Keithley SourceMeter 2611, User Manual

Page: 98 / 108

B-12 Frequently Asked Questions Series 2600 System SourceMeters User’s Manual
2600S-900-01 Rev. A / May 2006 Return to In this Appendix:
How do I make contact check measurements?
Reference Refer to “Contact check measurements” in Section 4 and command
information in Section 12 of the Series 2600 Reference Manual for
contact check details.
Contact check connections
The contact check function
1
prevents measurement errors due to excessive
resistance in the force or sense leads caused by poor contact at the DUT, failing
relay contacts on a switching card, or wires that are too long or thin. The contact
check function will also detect an open circuit that may occur when a four-point
probe is misplaced or misaligned.
Figure B-5 shows contact check connections.
R
C
is the resistance of the mechanical contact at the DUT, and R
S
is the series
resistance of relays and cables.
Figure B-5
Contact check connections
S LO
LO
CHANNEL A
LO G LO HI G G G HI
S S
KEITHLEY Series 2600
HI
S HI
DUT
R
S
R
S
R
S
R
S
R
C
R
C
R
C
R
C
Cable/Relay
Resistance
Contact
Resistance
1. All Model 2611/2612s manufactured by Keithley Instruments support the contact check function. Only Model
2601/2602s with firmware revision 1.1.0 or later and SMU hardware revision E or later support the contact check
function. To determine the firmware and SMU hardware revisions, inspect the data returned by the
print(localnode.info()) command. The InstFwRev and SMUBrdRev keys contain the necessary information.