Fluke OF-500-01 OptiFiber, Technical Reference Handbook, Page: 119 / 278

Using the OTDR
Using the Real Time Trace
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3
Using the Real Time Trace
The OTDR's real time trace is updated several times each
second, depending on the length of the fiber and the
wavelength used. This function is useful for locating
intermittent problems, such as those that appear when a
connector or cable is stressed. You can also use the real time
trace to monitor splicing procedures.
For OFTM-56xxB modules with the dual wavelength setting
selected on the OTDR tab, real time trace runs at 850 nm for
multimode and 1310 nm for singlemode.
For OFTM-57xx modules with dual wavelength selected, the
tester uses the wavelength that produces the higher
dynamic range for the fiber length.
If a single wavelength is selected, real time trace runs at the
selected wavelength.
W
Caution
Read the instructions for splice machines before
using the OTDR to monitor splicing procedures.
The OTDR can interfere with the light injection
detection techniques used by some splicers.
Tip: The real time trace function uses a lot of battery
power. To maximize the battery’s life, plug in the ac
adapter when using this function for an extended
period of time.
The real time trace has two modes: auto length and fixed
length.
Auto Length: The tester updates its range and pulse width
at least every tenth screen update or whenever the trace
changes. These adjustments make the trace fill the screen
for the best overall view of the fiber. The locations of
connections and other trace features change if the range
changes. The real time trace starts in Auto Length mode.
Fixed Length: When you press
B
Fixed Length, the tester
uses parameters based on the current OTDR parameters,
even if the trace changes. (The tester may adjust the
resolution and range slightly at first for a faster test.) This
mode makes changes in the fiber’s length more obvious,
since the range is not adjusted to make the trace fill the
screen.
Pressing
B
again returns the trace to Auto Length mode.