To Test Input Resistance - HP 54520 Series Service Manual

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To test input resistance
To test input resistance
This test checks the input resistance of the vertical inputs. A four-wire measurement is used
for accuracy at 50 Q.
Specification 1 MQ +1% and 50 Q 41%
Equipment Required
. Equipment Critical Specifications Recommended
Model/Part
Digital Multimeter Measure resistance (4-wire) better than 0.25% HP 34401A
accuracy
Cables {2) BNC HP 10503A
Adapter BNC Tee (mi(f)(f) HP 1250-0781
Adapters (2) BNC (f} to dual banana (m) HP 1251-2277
Procedure
Set up the multimeter to make a four-wire resistance measurement.
Assemble the test cables
a Use the BNC-to-banana adapters to connect one end of each BNC cable to the
four-wire resistance connections on the multimeter.
b Connect the free ends of the cables to the BNC tee.
Connect the male end of the BNC tee to the channel 1 input of the oscilloscope.
Press the appropriate channel number key (bottom row) to select the channel menu.
Use the impedance softkey (second from bottom) to select 1 MQ, then 50Q pc, and
verify resistance readings of 1 MQ £10 kQ and 50 Q 40.5 Q respectively.
Record the readings in the Performance Test Record.
Repeat steps 3 through 6 on the remaining channels and the Ext trigger of the
HAP 54520A and 545224.
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