Tektronix TekRanger 2 TFS3031, Service Manual

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Performance Check – TekRanger (serial nos. below B052000)
3–28
TFS3031 TekRanger/TekRanger 2 Service Manual
Multimode Distance Accuracy Check
The multimode distance accuracy check is a test using a test fixture made up of a
2.2 km length of multimode fiber with known length (time of flight).
1. Connect the multimode fiber of known length to the instrument multimode
port.
2. Make the following selections in the Setup menu:
H
Wavelength: 850 nm or 1300 nm (based on instrument options)
H
Fiber Scan: IntelliTrace
H
IR: 1.4776 at 850 nm and 1.4719 at 1300 nm
3. Exit the Setup menu.
4. Push the button to start an IntelliTrace acquisition.
5. When the acquisition is complete, compare the distance to event number two
in the TFS3031 event table to the known distance to the end of the multi-
mode fiber. This distance should be within the distance tolerance in the
specifications.
The following configuration illustrates the test fixture. There is one roll of fiber
2.2 km (
200 m) in length. The length of the fiber is measured by the standard
time-of-flight method. This gives a propagation delay which can be mathemati-
cally translated into a known length at a given (assumed) group index.
This simulated waveform shows the location and description of the multimode
events captured on the OTDR.
Distance to event = 0 m
Type of event = Front panel
Distance calibrated = Yes
EVENT 1
Distance to event = 2200 m
Type of event = FC/PC connector end reflection
Distance calibrated = Yes
EVENT 2
= FC/PC
OTDR
TEST FIXTURE
—— This concludes the performance check ——