5120A/5115A Operations and Maintenance Manual
43
For general information about markers, see
5.2 Configuring the Allan Deviation Plot
The PNTS can display the Allan deviation of the input signals. This data shows how much
deviation there is over time between the Input signal and the Reference signal. All measurements
are referenced to the Input signal.
The Allan deviation screen shows the following:
Allan deviation plot of the collected data.
Current
τ
0
value displays in the upper-left corner.
Noise Equivalent Bandwidth of the input filter,
NEQBW,
is displayed in the upper right
corner. NEQBW describes the equivalent bandwidth of a filter for broadband (white)
noise and is the bandwidth of a rectangular characteristic filter having the same power
transfer function as the selection filter (same area under the curve).
The 5120A and 5120A-01 perform cross-correlation. They are able to compute the noise
floor and shade the region below the measurement noise floor in gray.
The 5115A does not perform cross-correlation, and cannot shade the measurement noise
floor region. Instead it computes error estimates and presents those estimates using red
vertical bars along with each measurement.
The following can be configured:
Plot scale (see
)
τ
0
setting (see
)
Test mask (see
5.2.1 Scaling the Allan Deviation Plot
The Allan deviation plot can be scaled automatically or manually.
To scale the plot:
1. Press
Allan Deviation Plot (see
.
2. Press
Config Allan Deviation
.
3. Press
Scale Plot
.
The highlighted softkeys show the current settings.
Press
Auto Scale X Axis
or
Auto Scale Y Axis to auto scale either axis
.
To scale the plot manually, press one of the following:
•
Fixed Scale Y Axis
-
Use
Inc Min
or
Dec Min
to increase or decrease the minimum scale value.
-
Use
Inc Max
or
Dec Max
to increase or decrease the maximum scale value.
•
Fixed Scale X Axis
Содержание 5115A
Страница 6: ...iv Contents Index 97 ...
Страница 12: ...6 1 Introduction ...
Страница 16: ...10 2 Setting Up a PNTS ...
Страница 26: ...20 3 The Screen and Basic Concepts ...
Страница 82: ...76 9 Maintaining a PNTS ...
Страница 92: ...86 Appendix A Specifications ...
Страница 98: ...92 Appendix B Theory of Operation ...
Страница 100: ...94 ...
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