OTDR testing refers to the process of obtaining information about the state of an optical fiber cable. It can also be used to locate faults in the cable. It is also useful in identifying loss and measuring the length of a fiber. OTDR test methods are essential for fiber optic systems.
A OTDR uses the index of refraction, which is a calibration of the speed of light in a fiber. The amount of light reflected back from the fiber will be proportional to the peak power of the OTDR test pulse.
Aside from displaying a graphical signal, an OTDR can store data on its internal memory. The output is available via an RS232 link. The device can be programmed to do LSA or least squares analysis, which is a statistical method of reducing noise in the measurement.
Some OTDRs can use an onboard printer to print out before and after images for fault repair. It can also be set to display a real-time signal from the fiber. This is useful for analyzing connectors and optimizing mechanical splices.
What is OTDR Tester Used for?
Optical Time-Domain Reflectometer (OTDR) is an instrument that is used to measure optical return loss, fiber length, splice loss, and more. The data that is collected by the OTDR is used to generate a picture known as a trace. The traces can be useful for troubleshooting and testing the quality of a cable.
The OTDR is a common tool for fiber optic cable plant testing. Most OTDRs offer the ability to compare traces. This allows users to compare and contrast a trace between two test sessions from the same cable plant.
During the test, a pulse of light is inputted into the fiber cable. After the initial pulse, the OTDR will start timing the event. Once the event is complete, a signal is returned to the OTDR port. This will provide the information that is required to determine the amount of loss.
The OTDR is also capable of detecting excessive stress on the cable. This may indicate a break, splice, or connector. OTDR data is stored for later reference. The output can be downloaded to a computer.
How to Read OTDR Test Results?
When it comes to reading OTDR test results, you want to know the proper way to interpret the trace. If you don’t, you could end up waste time and materials or have your tests turn up as inaccurate.
When you first get your OTDR, you need to choose a range and then make some measurements. Then, you can print your results and read them on your PC. Some OTDRs also have a printer onboard. This makes it easier to maintain and troubleshoot your OTDR.
To properly use an OTDR, you should avoid using it for events that you don’t want to measure. For instance, splices and connectors. You should also be sure to set up markers before you begin. These markers will define the segments you’ll be testing.
The best time to use an OTDR is when testing long cables. The longer the cable, the greater the accuracy you can expect. The more accurate the measurement, the less noise you’ll be able to see.
A few important OTDR measurements include backscatter and reflectance. Both measures involve the index of refraction of the fiber, which is a calibration for the speed of light. The OTDR can also calculate the length of a cable and the distance between two points.
