Lambda SR1, Руководство по эксплуатации, Страница: 196 / 317

SR1 Operation Manual 196
© 2014 Stanford Research Systems
scaling controls and trace listing.
Toggles the cursors on and off.
Moves the active cursor to the next peak right or left.
Add Annotation. Opens a text window and allows placement of text on the graph area.
Change Graph Title.
Access the Trace Calculator. The trace calculator functions are fully described in the
trace calculator section.
Scaling Tab
The graph scaling tab controls the scaling and unit selection for the active trace. Each axis can be
plotted logarithmically or linearly by clicking the "Log" checkbox for that Axis. Note that when the units
for an axis are already intrinsically logarithmic, such as "dBVrms", selecting "Log" will change the units
to their corresponding linear value (Vrms) and plot the data on a logarithmic scale.
Some unit selections in the scaling controls depend on analyzer settings. For instance power spectral
density units, such as V/v Hz, depend on the FFT analyzer's resolution and window settings. When
traces with these units are taken offline the units are "frozen" and conversion to other units may be
limited.
Lock Axes
Normally, each trace has its own pair of X and Y axes, and each trace can be scaled separately.
However, there are times when it is useful to be able to view several traces all plotted with the same
scaling on the same axes. Clicking "Lock Axes" causes SR1 to plot all traces that have X and Y axes
compatible with the active trace on the same axes as the active trace. Any subsequent scaling
operation, such as manually setting the scales or pressing one of the autoscale buttons, will scale
all
the traces with compatible axes rather than just the active trace.
X-Axis and Sweep Controls
The X-axis controls only apply to "strip-chart" type traces. The X-axis for such traces can be plotted as a
function of "Index" which is simply a sequential integer label that is applied to each new point, or as a
function of real time elapsed since the "Start" button was pressed. If index is selected all the points will
appear to have equal spacing even though the actual measurement intervals may vary widely. The index
numbering, or the time origin, may always be reset by pressing "Start" (on the speedbar or on the
keypad) again.
The second control governs the scaling of strip-chart traces. If "Scale" is selected the graph