Fluke OF-500 OptiFiber, Техническое справочное руководство

Страница: 102 / 282

OF-500 OptiFiber Certifying OTDR
Technical Reference Handbook
3-28
Using the Measurement Cursor
You can use the cursor on the OTDR trace to measure
distances and losses along the cabling. The cursor position
and readouts are stored with saved results.
As you move the cursor, the tester calculates averages
around the mark and cursor positions. This reduces the
effects of noise on measurements.
To use the cursor, do the following:
1 If the navigational cue above the softkey labels does
not say
O
Pan,
P
Cursor, press
E
until it does .
2 Use
C
Next Event / Previous Event or
K N
to move
the cursor to a starting point on the trace. Pressing
K
or
N
sets the direction for the
C
softkey
.
3 Press
D
Set Mark to set the mark; then use
K N
or
C
Next Event / Previous Event to move the cursor to
the desired ending point.
The following readouts appear on the screen:
Note
To change between
∆
dB and
∆
dB/km /
∆
dB/kft
press
F
from the OTDR TRACE screen; then
select MARKER DELTA MODE from the OTDR
FUNCTIONS menu.
• ∆
m or
∆
ft : The distance between the cursor and
the mark.
• ∆
dB : The difference in the power levels (in
decibels) between the cursor and the mark.
• ∆
dB/km or
∆
dB/kft : Power loss (in decibels) that
would occur over 1 km (1000 m) or 1 kft (1000 ft)
of cable based on the loss between the cursor
and the mark.
4 Press
D
Clear Mark to clear the mark.