Anritsu S251B - Manual (Page 56)

Performing a Calibration
Step 13. Press the START CAL key. Follow the instructions that appear in the message
area.
Step 14. Connect the Open, Short, and Load component to the test port and press the
ENTER key as prompted after connecting each component.
Refer to the “Performing a Calibration” procedure on page 4-3 for detailed cali-
bration steps.
NOTES:
For best calibration results — compensation for all measurement system uncer-
tainties — ensure that the Open/Short/Load is at the end of the test port or op-
tional extension cable; that is, at the same point that you will connect the
antenna or device to be tested.
For best results, use a phase stable Test Port Extension Cable (see Optional
Accessories). If you use a typical laboratory cable to extend the Anritsu test port
to the device-under-test, cable bending subsequent to the Open/Short/Load cal-
ibration will cause uncompensated phase reflections inside the cable. Thus, ca-
bles which are not phase stable may cause measurement errors that are more
pronounced as the test frequency increases.
For optimum calibration, Anritsu recommends using precision calibration com-
ponents.
4-10
Chapter 4 Measurements