Tektronix TekRanger 2 TFS3031, Service Manual

Page: 174 / 272

Performance Check – TekRanger 2 (serial nos. B052000 and above)
TFS3031 TekRanger/TekRanger 2 Service Manual
4–13
34
32
28
24
20
16
12
0.000 1.000 2.000 3.000
dB
km
1
2
3
4
5
Figure 4–7: Multimode Event-Detection and Dead-Zone Test Fixture: OTDR Trace
To characterize test fixture distances and losses, test the fixture using a large
number (approximately 40 units) of identically configured TFS3031 instruments.
Each instrument is connected to the fixture. Scan the fiber at least five times with
each instrument.
Scatter plots are constructed showing loss vs. distance data points for each event.
If 40 instruments are used, and each instrument is allowed to scan the fiber five
times, the total number of data points is 200.
Figure 4–8 is an example scatter plot for a 50 m event.
Statistical
Characterization of
Multimode Test Fixture