Keysight Technologies 86120B, User Manual

Page: 229 / 273

227
Performance Tests
Test 5. Amplitude Accuracy and Linearity
filled in.
10 Disconnect the fiber-optic cable from the optical power meter and connect it to the
Keysight 86120B’s OPTICAL INPUT connector.
11 Set the optical attenuator for the value that you recorded in Step 8 .
12 Place the polarization controller in the auto scan mode.
13 Press the Keysight 86120B’s front-panel Preset key.
14 Press List by Power, Appl’s, and then DRIFT .
15 After two minutes, stop the polarization controller’s auto scan function.
16 Press the MAX-MIN softkey so that MAX is highlighted. Enter the maximum drift
reading on the following line:
maximum drift: ____________
17 Press the MAX-MIN softkey so that MIN is highlighted. Enter the minimum drift
reading on the following line:
minimum drift: ____________
18 Use the values recorded in Step 8 , Step 16 , and Step 17 to calculate the power-
correction offset value as shown in the following equation:
Enter the calculate value on the following line:
power-correction offset: ____________
19 Change the attenuator to the settings shown in Table 6-22 . For each setting, record
the power measured on the Keysight 86120B.
After completing this step, the table’s column titled “Keysight 86120B Power Read-
ing” should be completely filled in.
20 Calculate the “Linearity” value for each row in the table using the following
equation:
21 Compare the linearity values with the specification listed in Chapter 7,
“Specifications and Regulatory Information” . The data may show multiple amplitude
plateaus separated by small amplitude steps. This is not a problem as long as the
offset
minimum drift maximum drift +
2
---------------------------------------------------------------------------
Pwr – =
Linearity Power Meter Reading HP 86120B Power Reading – offset – =