HP 8712C, Руководство пользователя, Страница: 259 / 559

Calibrating for Increased Measurement
Accuracy
Choose an Appropriate Calibration Method
For an example of performing an AM delay calibration refer to “Measuring AM
Delay” in Chapter 3.
Otherwise, follow these general steps when performing an AM delay
calibration:
1. Setup the analyzer for an AM delay measurement:
l
select
l
enter operating parameters other than the default
2. Press (CAL), and then one of the following softkeys:
This selection removes all frequency response correction. Absolute group
delay measurements will be uncalibrated. The accuracy of relative group
delay (group delay flatness) measurements will not be degraded as long as the
delay of the cables and adapters connected to the DUT is negligible.
A response calibration prompts you to connect a through cable in place of the
DUT as the calibration standard, and then measures it across the frequency
band you have defined, using the number of points you have defined. This
measurement is used to remove systematic frequency response errors.
AM Delay Calibration
Widening the frequency span after performing this calibration will invalidate
Interpolation
it, and restore the default calibration. You may narrow the span and the
analyzer will interpolate correction for the narrower span.
Refer to “Measuring AM Delay” in Chapter 3 for more information about AM
delay measurements.
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