Stanford Research Systems SR865A, Operation Manual

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Chapter 1 Getting Started 21
SR865A DSP Lock-in Amplifier
4. Connect the CH1 Output on the front panel to
the DVM. Set the DVM to read dc Volts. The CH1 output defaults to X. The output
voltage (with ratio disabled) is given by:
10V Expand Offset
y Sensitivit
X
CH1
u u
¸¸¹
·
¨¨©
§
In this case, X = 0.1 V, Sensitivity = 1 V, the
offset is zero percent and the expand is 1. The
output should thus be 1 V or 10% of full scale.
Note that the bar graph for X (and R) is at
+10%. The Sensitivity (1 V) sets the full scale
for the bar graphs of X, Y and R.
5. Press [Screen Layout] twice to show the half
screen strip chart. Now let’s look at how the Sensitivity affects the
different displays.
6. Touch the green scale tile {X} to display its
scale palette.
Touch to auto scale the green X trace.
Touch the green highlighted scale tile again to
dismiss the scale palette.
auto scales the trace keeping zero at the
center. The zero location is indicated by the
small green triangle on the right edge. The scale
is 50 mV/div so the green data is a line 2
divisions above the center.
7. Press [Sensitivity Down] to select 500 mV. The DVM should now read 2 V. This is because
X (100 mV) is now 20% of the sensitivity
(500 mV). This also increases the bar graph to
+20% and increases the resolution of the
numeric readout.