User`s guide

C Specifications Definition of Terms / Measurement Conditions
198 E6000C Mini-OTDR User’s Guide, E0302
Measurement: The measurement is similar to the
measurement of distance offset error. Divide the
calculated distance sampling interval in at least four
distance increments and prepare incremental fibers to
cover all these increments. For example, to divide a
sampling interval of 10 m into 4 intervals, one needs two
incremental fibers of 2.5 m and 5 m to generate
increments of 2.5 m, 5 m and 7.5 m. Add each
combination of incremental fibers to the length L as
described in clause "distance scale error" and record the
individual differences
where
L = known length of the fiber = (c T)/N.
i = current increment
D = length of the smallest increment (i.e. the difference
between the increments).
Then calculate the distance sampling error
∆L
S
by
subtracting the smallest value of the
∆L
S,i
set from the
largest one. Express the result as ±half the difference.
Distance scale error
The difference between the average displayed distance
between two distinct locations on the fiber, L
OTDR
, and
the correspondent actual (true) distance, L, divided by
the actual distance, in meters per meter. See Figure 3.
.and
c = speed of light in vacuum
() DiLLS
otdriL
+−=∆
,
where
L
LL
S
otdr
L
−
=∆
N
cT
L =