23
fiber: 850nm, 1300nm; wave length of single mode fiber: 1310nm, 1550nm; wavelength of single
mode fiber of PON network: 1490nm, 1625nm. According to the differences of models, users
can simultaneously select 3 wavelengths at most to measure. This kind of measurement model
is called “multi wavelength measurement model”. Under “multi wavelength measurement
model”, measurement of multi wavelength output from the same optical interface will be
automatically and successively completed. Users can set analysis and file saving with different
wavelength. In addition, multi wavelength measurement is valid only under the average
measurement mode. Multi wavelength measurement is forbidden under the real-time
measurement mode.
Distance scope: selected by user, options include “auto, 300m, 1Km, 5Km, 10Km, 30Km,
60Km, 100Km, and 180Km”.
Pulse width: selected by user, options include “auto, 5ns, 10ns, 20ns, 40ns, 80ns, 160ns,
320ns, 640ns, 1.28
µ
s, 2.56
µ
s, 5.12
µ
s, 10.24
µ
s, and 20.48
µ
s”
Duration of measurement: selected by user, options include “5s, 10s, 15s, 30s, 1min, 2min,
and 3min”. If the current measurement model is real-time measurement, the selected duration
of measurement won’t play role in the measurement.
Measurement model: selected by user, options include “average measurement and
real-time measurement”. When selecting real-time measurement mode, the selected duration
of measurement won’t play role in the measurement.
Length unit: meter. No option or user setting is provided in OTDR instrument.
Refractivity: set by user, input scope: 1.0000~1.9999, default value is set to be: 1.4685
Back scattering coefficient: it is to provide OTDR with a relative back scattering electrical
level for the given optical fiber. Back scattering coefficient is set before delivery. Usually,
technicians won’t change the parameter. If the back scattering coefficient is changed, it will
influence the reflection value and optical return loss that reported by instrument. No option or
user setting is provided in OTDR instrument.
Reflection threshold: No option or user setting is provided in OTDR instrument.
Non-reflection threshold: set by user, input scope: 0.01~2.99, the default value is: auto.
When the manual setting value is 0.00, it will transfer to auto value.
Bundling threshold: it is used as the threshold value for looking over event point when the
instrument treating data, i.e.: event points that lower than the set value of bundling threshold will
be removed, while the event points that higher than the set value of bundling threshold will be
displayed. For options set by user, input scope is: 1~19.99dB, the default value is: 5.00dB.
Default setting recovery: distance scope is “auto”; pulse width is “auto”; duration of
measurement is “10 sec”; laser wavelength is
‘
1550nm’, measurement model is “average
model”; length unit is “meter”; refractivity is “1.4685”; back scattering coefficient is “auto”;
reflection threshold is “auto”; non-reflection threshold is “auto”; bundling threshold is
“5.00dB”.
