Figure 1-8 Impedance Verification Setup - Keysight 8990B Service Manual

Four-wire resistance
connections
Figure 1-8
7 Press Default Setup on the 8990B to set the 8990B to its default settings.
8 Set the vertical scale for the video input channel 2 to 10 mV/div.
9 Set the input impedance for the video input channel 2 to 50 Ω. and verify the
10 Measure and record the resistance reading from the multimeter in
11 Repeat
12 Repeat
13 Repeat
14 Compare the recorded values with the specification values as listed in
Table 1-3 Test record for impedance verification
Input impedance Vertical scale
50 Ω 0.01 V/div
50 Ω 0.02 V/div
Keysight 8990B Service Guide
34410A
Impedance verification setup
resistance reading with 50 Ω ±1.25 Ω.
step 4 to step 10
step 4 to step 11
resistance reading with 1 MΩ ±10 kΩ.
step 4 to step 12
Table 1-3. If the test fails, refer to
Video input
channel 2
Performance Verification and Adjustments
8990B
for the rest of the vertical scale setting in
with the input impedance set to 1 MΩ. and verify the
for the video input channel 3 of the 8990B.
"Adjustments"
Video input
Limits
channel 3
48.75 Ω to 51.25 Ω
48.75 Ω to 51.25 Ω
Table
Table
on page 51.
1
1-3.
1-3.
37