The prospect of high-bandwidth access has been exploding and if you are someone who has been invested in learning more about these concepts and how fiber optic networks work, chances are that you are overlooking one of the most integral elements in the process – the Fiber Optic Cable.
Amidst all the elements that make up the fiber optic network, it is the fiber optic cable that’s responsible for maintaining continuity and ensuring that the entire network is functioning optimally and without any hindrances.
This is one of the reasons why testing fiber optic cable is a necessity from time to time. If you are new to the whole concept and have been wondering how to navigate through the process, we have sorted all the information for you in this guide.
Understanding the Basics of a Fiber Optic Cable
Before we explain the steps involved in the testing of a fiber optic cable, we must prioritize the basic understanding of what a fiber optic cable is and how it works.
There are four primary elements in a fiber optic cable, including:
- Core – This is the central region through which the light travels.
- Cladding – This is the outer layer that reflects the light into the core.
- Coating – This is a protective external layer that wraps around the cladding.
- Jacket – This is the outermost layer, which provides the optic cable with the mechanical protection it needs.
With the basic rundown of the structure and composition of the fiber optic cable out of the way, let us familiarize you with the types. There are two major types of fiber optic cables available:
- Single-Mode Fiber (SMF) – Ideal for long-distance communication.
- Multi-Mode Fiber (MMF) – Ideal for shorter distances and lower bandwidth transmission.
Why is Fiber Optic Cable Testing a Necessity?
Fiber optic cable testing is a necessity for several reasons. Keep in mind that testing at regular intervals is crucial to ensure that there are no risks or interruptions in the cable for proper transmission.
Some of the reasons why timely testing of the fiber optic cable is a necessity are:
#1. Proper Installation and Performance
One of the main reasons why you need to test the fiber optic cable from time to time is to ensure that the installation process has been done properly and the performance is optimal. Since the cables are quite delicate and complex, even the slightest errors can lead to interruption in the performance.
Testing from time to time can help identify and fix installation errors to meet specific performance requirements.
#2. Troubleshoot Problems
If you are experiencing issues like slow speed or internet outages, these are signs that something is potentially not right with the fiber optic cable. In that case, testing helps you identify the root cause and then troubleshoot the problem accordingly.
Doing so will not only save you a lot of money, it can save you enough time by preventing the need to call or hire a professional technician to do the job for you.
#3. Maintain Network Performance
The most vital reason why you should be testing your fiber optic cable from time to time is to ensure that it translates well into the network performance.
Fiber optic networks can degrade over time due to factors such as dust, dirt, and moisture. Testing frequently will not only help you identify those errors early on but also ensure that you can implement relevant fixes to overcome the issue proactively.
#4. Comply with the Regulations
Not many users are aware of this but testing your fiber optic cable is not just a mere tradition, it is often considered a necessity to meet relevant regulations too.
This specifically applies to industries like finance and healthcare where data transmission and security are top priorities. Testing regularly is to ensure that the networks are meeting the high standards of performance that are set for them.
What are the Different Types of Tools Involved in the Fiber Optic Cable Testing?
Before we take you through the list of different types of tests for fiber optic cable, you must understand the different types of tools that are used for testing fiber optic cable.
- Visual testing tools – Fiber inspection microscope, fiber inspection scope, video inspection probe.
- Continuity testing tools – Visual fault locator
- Connector and adaptor tools – Connector cleaners, connector inspection tips, fiber optic adapters
- Insertion loss and return loss testing tools – Launch and receive cables, return loss meter, test reference cables, etc.
- Polarization mode dispersion (PMD) and chromatic dispersion tools – PMD analyzer, chromatic dispersion analyzer
- End-to-end testing tools – Transmitters and receivers, optical power meters, light sources
- Documentation and reporting tools – Test record sheets, fiber test management software, etc.
- Power meter and light source tools
- Optical Time Domain Reflectometer (OTDR)
Once you have all the relevant tools in check, next is the actual testing process, which will take a significant amount of time, so be prepared accordingly.
What are the Different Types of Fiber Optic Cable Testing?
Now that you have a good idea about the tools that you need for the testing, let us walk you through the list of different types of tests involved.
#1. Visual Inspection
The most basic form of testing the fiber cable optic is by doing a visual inspection of the entire thing. What you achieve with this type of testing is to look for visible faults and damage in the cable.
Steps involved in a visual inspection process include inspecting the cables and connectors for signs of physical damage like cracks, bends, or even contaminants.
#2. Continuity Testing
The next one on the list is continuity testing, which as the name suggests, helps to confirm if there are any kinds of breaks or open circuits in the fiber optic cable.
Some of the tools that are generally used for this kind of testing include a continuity tester or a light source and power meter, which verify the cable’s continuity.
#3. Power Meter and Light Source Testing
This kind of testing helps in measuring the signal loss or attenuation in the fiber optic cable to meet the standard requirements.
For conducting this test, you’d need a stable light source and a power meter to measure the transmitted and received power levels.
If you want a breakdown of the steps involved, here’s what you need to do:
- Start by connecting the fiber optic flashlight to one end of the strand of the optic fiber.
- Look at the opposite end, ensuring that you are practicing caution and not looking directly since it can damage the eyes.
- If the light visibility isn’t clear and optimal, there is a break or issue in the optic fiber cable.
In that case, you’d have to change the cable or mend the issues that you think could be contributing to the problem.
#4. Optical Time Domain Reflectometer (OTDR) Testing
This is one of those testing processes that not everyone is aware of. The main objective of this type of testing is to locate the faults, and splice losses, and measure the fiber’s overall attenuation along its length.
If you are new and wondering how this test works, let us explain in brief.
OTDR sends a pulse of light into the fiber and measures the reflections and backscatter to create a profile of the cable. So, if there are any faults or issues with the cable, the device will be able to detect the same.
#5. Insertion Loss Testing
If you are experiencing signal loss and poor performance due to your fiber optic cable, insertion loss testing can determine what’s wrong and help you navigate through the issue without any hassle.
The test measures the loss of signal strength introduced when connectors or splices are added to the fiber optic system. The process of conducting this test is simple. All you have to do is note down the power level before and then after the splice.
#6. Polarization Mode Dispersion (PMD) Testing
Another underrated test for checking the functionalities of a fiber optic cable is the PMD testing. The test helps assess the variation in signal propagation times between different polarization modes in the fiber.
The test involves the use of a PMD analyzer, which measures the PMD values to check how functional the fiber is and if any elements in the fiber need to be changed or replaced.
#7. Chromatic Dispersion Testing
One of the most common issues that we often overlook with the fiber optic cable is signal distortion. It happens a lot and could be one of the main reasons why the network stability and speed are affected.
If you are experiencing a similar issue and want to get a better understanding of what’s wrong, conducting chromatic dispersion testing can be a great way to identify the level of signal distortion that is caused by different wavelengths traveling at different speeds.
For this, a chromatic dispersion analyzer is used, which measures the degree of dispersion and if the amount is more than normal, it indicates severe faults that need to be addressed.
#8. End-to-end Testing
Last on the list is to check the status of the function of the entire fiber optic cable from the start till the end. This includes connectors, splices, and the cable itself to see if it is meeting the standard performance requirements as it should.
The process of conducting this test is simple. It involves transmitting test signals from one end and the received signals are measured at the other end. Any kind of distortion in the amount of received signals indicates that there could be some kind of issue.
Conclusion on How To Test Fiber Optic Cable
Fiber optic cables come with a plethora of benefits and if you have been wondering why is it significant to conduct regular testing of the cable, we hope this guide gives you a comprehensive rundown of the reasons. You must check the fiber optic cable’s vitality from time to time to be able to avert risks and ensure optimal performance.
FAQs on How To Test Fiber Optic Cable
Q1. What are the typical limits for acceptable fiber optic cable performance?
Ans: Acceptable performance limits vary based on the type and application of the fiber optic cable. Consult industry standards and specifications for guidance.
Q2. How often should fiber optic cables be tested and maintained?
Ans: Regular testing and maintenance depend on the specific network and environmental conditions but are typically recommended annually or during major network changes.
Q3. What is return loss, and how does it affect fiber optic systems?
Ans: Return loss measures the amount of light reflected towards the source. It can affect signal quality and network performance, making it important to minimize.
Q4. How do I visually inspect fiber optic connectors and end faces?
Ans: Use a fiber inspection microscope or scope to examine connectors and end faces for cleanliness and defects. Ensure good lighting and proper magnification for a detailed view.
Q5. Can fiber optic cables be tested for bend or stress-related issues with a VFL?
Ans: Yes, a VFL can help identify bend or stress-related issues in fiber optic cables by causing visible light leakage at these points. However, specialized bend-insensitive fibers may not exhibit this behavior.
Hi, I am James Burns a skilled and experienced network engineer with a passion for optimizing digital connectivity. With a wealth of expertise in designing and managing intricate network infrastructures, I excel in enhancing performance and security. I hold a distinguished record of delivering top-notch results in various Network courses, including the Juniper Networks Certified Associate (JNCIA) certification, demonstrating my commitment to continuous learning and professional growth. My dedication to staying at the forefront of emerging technologies makes me an invaluable asset in ensuring seamless and reliable network operations. Whether troubleshooting complex issues or implementing innovative solutions, I am dedicated to creating robust and efficient network environments for businesses and individuals alike.