TB 9-6625-2309-35
(13) Repeat technique of steps a(3), (4)(b), (11) and (12) for next digital delay/pulse
generator A=T+ value on TD-260C data sheet (appendix A) (first cluster) until a shift to
right of cursor A FOCUS generated pulse is observed. Record this A= km TI indication on
data sheet. When shift occurs, this is the final measurement required for this cluster.
NOTE
Press TI PULSE WIDTH pushbutton to select LONG for
second cluster measurements.
(14) Repeat technique of steps a(1) through (13) for second cluster using A=T+ values
on TD-260C data sheet (second cluster).
(15) Load TS-4320 Optical Fiber Test Set calibration software to an MS-DOS
compatible PC according to instructions in TS-4320, Calibration Software User's Manual.
(16) Access Distance Scale Calibration menu.
(17) Access data entry page and enter insertion delay and index of refraction (1.
4990) for constants entry. On data edit page enter only last two digital delay/pulse
generator settings for A=T+ (s) and respective TI A= (km) values for each cluster from TD-
260C data sheet (appendix A).
NOTE
Time insertion delay (TID) is given in nanoseconds with each
FOCUS unit on FOCUS Time Insertion Delay Measurement
Worksheet. Time insertion delay may be different for each
wavelength and FOCUS control module. Be sure to use correct
insertion delay for control module and wavelength being used.
(18) Verify entered data is correct then quit data edit page.
(19) Select Generate Report and then Graphic Report screen to view resultant
plot (fig. 7).
NOTE
Two dashed lines on graphical report represent boundaries of
normally acceptable uncertainty for TI.
Beyond 65 km,
boundaries are increased to allow for additional tolerance at
long range. If least squares line fitted to data points is outside
these boundaries, TI is considered out of tolerance (data points
outside of boundaries are acceptable). In this case, verify data
entries and constants on data entry page. Repeat calibration
before TI is adjusted or repaired. Select Graphic Report
(Printer) to print a hard copy if needed. Also, tabular report
can be viewed or printed.
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