Specifications

Chapter 3: Testing Performance
DC Gain Accuracy Test
27
6 Change the Cal Out voltage to - 30 mV.
7 Press [Clear Display] on the scope, wait for the #Avgs value to return to 256 and then
record the DMM voltage reading and the scope V avg reading in the DC Gain Test
section of the Performance Test Record.
8 Calculate the DC gain using the following expression and record this value in the DC
Gain Test section of the Performance Test Record.
For vertical sensitivities of less than 1 volt use the following equation:
For vertical sensitivity = 1 V use the following equation:
9 Repeat steps 3 to 8 for the remaining channel 1 vertical sensitivities in the DC Gain
Test section of the Performance Test Record. For each measurement, set both the Cal
Out voltage (V
CalOut
) and the Channel offset voltage to the positive V
CalOut
value and
then to the negative V
CalOut
value in the “V
CalOut
Setting” column of the DC Gain Test
table in the Performance Test Record for each of the vertical sensitivities.
10 Move the Tee connector to the next channel input and repeat steps 3 to 9 for channels
2 to 4 and for channels 1R and 3R.
Record the
mean reading
DCGainError =
ΔV
out
ΔV
in
--------------
=
V
scope+
– V
scope-
V
DMM+
– V
DMM-
-----------------------------------------
1–


75⋅
DCGainError =
ΔV
out
ΔV
in
--------------
=
V
scope+
– V
scope-
V
DMM+
– V
DMM-
-----------------------------------------
1–


60⋅

