Stanford Research Systems SR865 Operation Manual page 24

6 Getting Started
past. The time interval is determined by the horizontal scale per division and the number
of pixels in the display. There are 640 pixels across 10 divisions of the graph. Thus there
are 64 pixels in each division. At a scale of 0.5 s/div, each pixel represents about 8 ms of
data. At a scale of 1 min/div, each pixel represents about 1s of data. This 'binning' is
fundamental to the SR865 strip chart display. All time scales are stored all of the time.
This allows the horizontal scale to change without re-acquiring any data. The caveat is
that all graphs are drawn with the most recent point at the right hand edge.
Zooming in and out (changing the horizontal scale) always displays the most recent point
at the right edge. There is no zooming in about a point in the distant past.
All parameters which may be assigned to a data channel are continuously recorded even
when they are not displayed. This means that historical data can be viewed for all
parameters simply by assigning them to a data channel and viewing the strip chart.
Strip charts may be paused. When the graph is paused, the cursor can be used to readout
data values. Data storage continues in the background while the graph is paused. When
live scrolling is resumed, the graph is redrawn so the most recent point is once again at
the right edge.
Graph Scale Bar
Strip Chart displays have a scale bar at the bottom of the screen.
This bar shows tiles indicating the vertical scale per division for the 4 data channels
(green, blue, yellow and orange) and the horizontal time scale per division (white).
Touch a data channel's scale tile to display a palette of scale functions.
SR865 DSP Lock-in Amplifier
Chart vertical scale palette
Chapter 1