Tektronix ATEC TekRanger 2, Руководство пользователя

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Setups
TFS3031 TekRanger/TekRanger 2 User Manual 1–27
Refractive Index
Refractive index is the ratio between the speed of light in a vacuum
to speed of light in a fiber.
Refractive index varies from fiber to fiber and is an important setup
for achieving accurate test results. A change in the refractive index
affects the distance scale on the screen and fiber measurements.
The refractive index is usually available from the fiber manufacturer.
Refer to Table 1–1 on page 1–11 for factory default settings.
Refractive Index is user settable in all modes.
If the refractive index of a fiber is unknown, you can calibrate the
index using a known length of fiber, or a fiber containing a segment
of known length, as follows:
1. Test the fiber and display the waveform.
2. Position Cursor A on the first point on the leading edge of the
event at the start of the fiber segment. Position Cursor B on the
leading edge of the event at the end of the segment.
For precise cursor positioning, zoom the waveform (see page
2–15 for instructions on moving the cursors and page 2–19 for
information about zooming).
3. Access the Refractive Index setup in the Test menu.
4. Use the arrow keys to change the Refractive Index parameter. As
the parameter changes, the distance scale readjusts, changing the
distance to the cursors. When the A–B distance on the Test Setup
menu matches the known length of the fiber segment, the
Refractive Index setup is correct.
Setups
TFS3031 TekRanger/TekRanger 2 User Manual 1–27
Refractive Index
Refractive index is the ratio between the speed of light in a vacuum
to speed of light in a fiber.
Refractive index varies from fiber to fiber and is an important setup
for achieving accurate test results. A change in the refractive index
affects the distance scale on the screen and fiber measurements.
The refractive index is usually available from the fiber manufacturer.
Refer to Table 1–1 on page 1–11 for factory default settings.
Refractive Index is user settable in all modes.
If the refractive index of a fiber is unknown, you can calibrate the
index using a known length of fiber, or a fiber containing a segment
of known length, as follows:
1. Test the fiber and display the waveform.
2. Position Cursor A on the first point on the leading edge of the
event at the start of the fiber segment. Position Cursor B on the
leading edge of the event at the end of the segment.
For precise cursor positioning, zoom the waveform (see page
2–15 for instructions on moving the cursors and page 2–19 for
information about zooming).
3. Access the Refractive Index setup in the Test menu.
4. Use the arrow keys to change the Refractive Index parameter. As
the parameter changes, the distance scale readjusts, changing the
distance to the cursors. When the A–B distance on the Test Setup
menu matches the known length of the fiber segment, the
Refractive Index setup is correct.