This is a fiber optic cable testing device that injects a series of optical pulses into the fiber under test and extracts, from the same end of the fiber, light that is scattered The strength of the return pulses is measured and integrated as a function of time, and plotted as a function of fiber length. which is called TRACE
3. OTDR Working Principle
The OTDR’s operating principle is based on
the measurement of the Raleigh
Backscattering Signal, generated by sending
a high power optical pulse from the OTDR
through the optical fiber. Light is reflected
back to the OTDR.
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4. This backscattered light is
measured by the sensitive optic
receiver, converted to digital form
and averaged to improve the
signal to noise ratio
5. The resulting signal forms a graph called a
TRACE. The trace is a visual
representation of the backscattering
coefficient created by the OTDR to
determine the “events.” The trace shows
the “events” on the fiber optic link such as
breaks, splice loss, bends, attenuation and
distance
6.
7. OTDR MACHINE WINDOW
MENU
5 Basic menu every OTDR must have
•Trace title
•Menu bar
•Button toolbar
•Information Panel
•Trace window
9. GENERAL OTDR
FEATURES
OTDRS CAN BE CATEGORIZED BY
•Their operating wavelength,
•Their dynamic range (the length of optical fiber
link over which they will operate),
•Their sensitivity or resolution. OTDR sensitivity is
its ability to differentiate between closely spaced
events.
10. OTDR OPERATIONAL TOOL
BAR
THESE ARE THE TOOLS FOUND ON
THE BUTTON TOOL BARS FOR THE
SMOOTH OPERATION AND ANALYSIS
OF THE OTDR TRACE
11. Attenuation measurement by straight-line trace
approximation [D]
Restores all trace scales [ALT+BKSP]
Opens up the measurement parameters
window
Starts the measurement process in real time
mode [ENTER]
Vertical zoom out control [CTRL+V]
Automatic trace analysis [A]
Deletes all the marks between markers
[ALT+DEL]
Horizontal zoom out control [CTRL+H]
Applies a template to current trace [CTRL+T
Inserts trace from clipboard onto host trace
[SHIFT+INS]
Trace information [I]
Reflection coefficient measurement [R]
OF refractive index adjustment [N]
Inserts a mark for the current mode and marker
position [CTRL+ENTER
Opens a table of the current trace marks [Т]
Copies current trace to clipboard [CTRL+INS]
Deletes inserted trace [CTRL+DEL]
Horizontal zoom in control [H]
Vertical zoom in control [V]
Attenuation measurement in OF junctions [S]
Attenuation measurement between two points
mode [P]
Starts the measurement process in Normal
mode
Saves a current trace [CTRL + S]
Prints a current trace
Opens a previously saved trace [CTRL + O]
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12.
OTDR Operations
In addition to the trace analysis, the OTDR will
determine the following
Distance of the fiber link
Attenuation of the fiber link
The fibers ORL
Splice loss
Connector loss
13. WHAT TO OPERATE ON
OTDR
Every OTDR user must know how to
adjust the distance to be displayed on the screen
adjust the dB for vertical scale representations
select various wavelengths
adjust the transmission pulse widths
select a vertical position on the screen using the curser
print, save, and execute other file commands
14. OTDR ACCEPTANCE
TEST
Acceptance testing provides a quality assurance
notification to the installation crew that the cable
meets the manufacturing standards, and is not
damaged.
It ensures that:
•the cable meets the manufacturer's specifications for
optical attenuation requirements
•the footage of the reel is correct
•the cable remains undamaged from shipment and
handling