Notes On Accuracy - HP 8753E User Manual

Notes On Accuracy

The accuracy values in 'Iable 6-7 were derived by combining the accuracy of the power meter
and linearity of the analyzer's internal source, as well as the mismatch uncertainty associated
with the test set and the power sensor.
Power meter calibration measures the source power output (at the measurement port) at a
single stimulus point, and compares it to the calibrated power you selected. If the two values
are different, power meter calibration changes the source output power by the difference. This
process is repeated at every stimulus point. The accuracy of the result depends on the amount
of correction required. If the selected number of readings = 1, the final measurement accuracy
is significantly affected by a large power change. However, if the selected number of readings
is > 1, the power change on the second or third reading is much smaller: thus accuracy is much
better.
Set source power approximately correct at the measurement port, then activate power meter
calibration. This method can significantly increase the accuracy of the measurement when the
selected number of readings = 1. Smaller accuracy improvements occur with a higher number
of readings. Remember that mismatch errors affect accuracy as well.
Power meter correction applies to one port only; the other port is not
Note
corrected.
Application and Operation Concepts