What you need to set first for make the measurement by OTDR?

The first OTDR parameter to set is the range, which is the distance over which the OTDR will measure. Then set the OTDR test pulse width to the shortest pulse width available which will provide the highest resolution (right), giving the best “picture” of the fiber being tested.

How does a OTDR work?

OTDR injects a series of optical pulses into the fiber under test. It also extracts, from the same end of the fiber,light that is scattered or reflected back from points along the fiber. The strength of the return pulses is measured and integrated as a function of time, and is plotted as a function of fiber length.

How do you test OTDR fiber?

The OTDR sends a pulse of laser light into one side of the optical fiber. As the pulse travels along the fiber, a small portion of the pulse’s energy is reflected to the detector from points along the fiber, such as connectors, multiplexers, splices, splitters and other components on the optical link.

What is the preferred wavelength setting for the OTDR?

Generally speaking, 1625 nm is the preferred wavelength for monitoring legacy 1310/1550-nm systems, largely due to laser cost. The 1650-nm wavelength is recommended for CWDM, DWDM, XGS-PON, and TWDM-PON systems where the traffic wavelengths extend into the L-Band.

How long does OTDR testing take?

It typically takes at least 3 minutes for a skilled OTDR technician with high-quality equipment to obtain one trace. Printing out the trace adds another 2 to 3 minutes per fiber. In a system of only 48 fibers, this adds approximately 5 man-hours, including set-up time, to the testing procedure.

How long does an OTDR test take?

What is a gainer on an OTDR trace?

Akin to water flowing from a small pipe into a large pipe, gainers are essentially perceived increases in optical power that occur at splice points due to variations in fiber characteristics, including core diameter, numerical apertures, mode field diameters and backscatter coefficients.

What is pulse in OTDR?

In an OTDR, the pulse carries the energy required to create the backreflection for link characterization. The shorter the pulse, the less energy it carries and the shorter the distance it travels due to the loss along the link (i.e., attenuation, connectors, splices, etc.).

What is wavelength in OTDR testing?

OTDR test pulse width wavelength: Normally, it’s 850 nm on multimode fiber optic cable and 1,310 nm on single-mode—the shorter wavelength has more back-scatter, so the trace will be less noisy.

What is pulse rate in OTDR?

What does pulse width control on an OTDR?

What is Pulse Width? OTDR pulse width determines length of fiber that can be measured before OTDR traces become noise. Larger pulse width provides larger dynamic range. Narrow pulse width provides reduced dynamic range.