Keithley 2182, Service Manual, Page: 18 / 120

4. Using either RANGE key, select FULL, then press ENTER. The unit will then remind
you to disconnect the input cable:
REMOVE INPUT
5. Make sure the input cable is disconnected, then press ENTER. The unit will then
perform auto-calibration, a process that will take several minutes to complete. During
this period, the unit will display:
ACAL
NOTE LOW-LVL ACAL performs a new gain calibration for the 10mV range only based on
10V calibration. FULL ACAL performs both a 100V and 10mV gain calibration
based on the last 10V calibration.
Performing the verification test procedures
Test summary
• DC voltage measurement accuracy
• Temperature measurement accuracy
• Analog output accuracy
If the Model 2182 is not within specifications and not under warranty, see the calibration
procedures in Section 2 for information on calibrating the unit.
Test considerations
When performing the verification procedures:
• Be sure to restore factory front panel defaults, and perform a full auto-calibration
(ACAL), as outlined above.
• Make sure that the Model 2182 and test equipment are properly warmed up, and that the
test equipment is connected to the appropriate Model 2182 jacks.
• Be sure the test equipment is set up for the proper function and range.
• Allow the test signal to settle before making a measurement.
• Use only copper-to-copper connections to minimize thermal EMFs.
• Make sure that all connections are clean and free of oxidation to avoid thermal EMFs
that could affect measurement accuracy. Clean oxidation from connector terminals with
DeoxIT cleaning solution.
• Keep test connections and all equipment away from drafts to avoid thermal drift.
• Do not connect test equipment to the Model 2182 through a scanner, multiplexer, or
other switching equipment.
• Do not use autoranging because autorange hysteresis may cause the Model 2182 to be
on an incorrect range.
Performance Verification 1-5