Automating Calibration Adjustment Procedures
The calibration procedures demonstrate front panel calibration. You can automate the complete veri-
fication and calibration procedures outlined in this manual. You can program the instrument con-
figurations specified for each test over the remote interface. You can then enter read back verification data
into a test program and compare the results to the appropriate test limit values.
The instrument must be unsecured to calibrate. See
for details.
Refer to the
for information on SCPI programming.
Input Connections
Test connections to the instrument are best accomplished using a Keysight Technologies 34172B cal-
ibration short for low–thermal offset measurements and a 34171B DMM connector configured to inter-
face to the calibrator output. Shielded, twisted–pair, PTFE interconnect cables of minimum length are
recommended between the calibrator and the multimeter to reduce settling and noise errors. HI and HI
Sense should be a twisted pair. LO and LO Sense should be a twisted pair. Cable shields should be earth
ground referenced. This configuration is recommended for noise reduction and settling time performance
during calibration.
Test Considerations
Errors may be induced by AC signals present on the input leads during a self–test. Long test leads can also
act as an antenna causing pick–up of AC signals.
For optimum performance:
l
Ensure that the calibration ambient temperature (Tcal) is stable and between 18 °C and 28 °C. Ideally
the calibration should be performed at 23 °C ±2 °C.
l
Ensure ambient relative humidity is less than 80%.
l
Allow a 90 minute warm–up period with a copper short connected.
l
Connect the input cable shields to earth ground. Except where noted in the procedures, connect the
calibrator LO source to earth ground at the calibrator. It is important that the LO to earth ground con-
nection be made at only one place in the circuit to avoid ground loops.
Because the instrument is capable of making highly accurate measurements, you must take care to ensure
that the calibration standards and test procedures do not introduce additional errors. Ideally, the stand-
ards used to verify and adjust the instrument should be an order of magnitude more accurate than each
instrument range full scale error specification.
For 2-wire ohms measurements, remove lead resistance by doing a null measurement with the leads shor-
ted or with a precision 4–terminal low thermal short. For offset calibration a 4–terminal low thermal short
is required.
Keysight True
volt
Series Operating and Service Guide
525
Calibration Adjustment Procedures
