User`s guide

Test IV. Distance Accuracy (Optional) D Single-Mode/Multimode Module Performance Tests
E6000C Mini-OTDR User’s Guide, E0302
243
The best approximation of the start position of the
reflection is: last point on backscatter + half sample
spacing, that is Samp. Dist.
Note result in test record 14 Note the distance between markers A and B (A <–>B)
plus the position of marker A (4.000 m), as Measured
Distance to the test record.
Repeat for other pulsewidth 15 Repeat steps 12 to 14 with the pulsewidth set to 100ns.
Evaluate data and enter in test
record
16 Evaluate the measurement data.
– Note the length of your optical fiber to the test
record.
– Note the start position to the test record.
– Distance accuracy
The distance accuracy is defined as:
Distance accuracy = (Measured Distance
× Scale
Error
+ Offset Error
± 1/2 Sampling Spacing)
Sampling Error = Sample Spacing
Distance accuracy =
± Fiber Length × 10
-4
± 1 m ±
0.08 m
– Calculate the minimum and the maximum distances
as described in the test record.
Note them in the test record and compare them with
the measured distances.
Measured Distance Known Fiber Length of Delay Line
Offset Error
± 1m
Scale Error
± 10
-4
Sample spacing with the 2km Span 0.161m