Agilent Technologies 54853A Service Manual page 54

Chapter 3: Testing Performance
Offset Performance Test
Change the channel 1 offset value to -120 mV.
18
Set the Aux Out voltage to -120 mV.
19
Press the Clear Display key on the scope, wait for the #Avgs value (top left corner of
20
screen) to return to 256 and then record the DMM voltage reading as V
scope Vavg reading as V
Record.
Calculate the offset gain using the following expression and record this value in the
21
Offset Gain Test section of the Performance Test Record:
Offset Gain =
Repeat steps 15 to 21 for the remaining channel 1 vertical sensitivities in the Offset
22
Gain Test section of the Performance Test Record. For each measurement, set both
the Aux Out voltage (V
value and then to the negative V
Offset Gain Test table in the Performance Test Record for each of the vertical
sensitivities.
Move the Tee connector to the next channel input and repeat steps 14 to 22 for the
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channels 2 to 4.
3–10
in the Offset Gain Test section of the Performance Test
Scope-
∆V
V – V
out scope+ scope-
------------- - = ------------------------------------------- -
∆V
V – V
in DMM+ DMM-
) and the Channel offset voltage to the positive V
Aux Out
value in the "V
Aux Out
DMM-
Setting" column of the
Aux Out
and the
Aux Out