1. What is optical fiber end-face testing and why is it important?
Measuring the integrity of fiber optic network installations is critical to enabling the fast transfer of communications data used by many industry sectors including industrial automation, datacenters, smart buildings and much more. Fiber-optic data communications require networks to operate at minimal downtime and maximum efficiency. However, the increasing diversity of fiber-optic applications has highlighted the need for adaptable and user-friendly test solutions.
One of the most important checks that installers and systems integrators can carry out is an end-face test, which involves checking the section of an optical fiber network that makes an interface with another fiber optic component. The design of fiber optic connectors and matching ports, varies depending on the application.
2. What problems do technicians face and how can testing tools help?
Technicians can struggle when working with fiber, particularly with fibers that are either not operating correctly or are simply not operating at all – often known as dark fibers. New-to-market testing tools can allow operators to carry out basic tests on fiber to easily identify polarity issues and failed transceivers. Safety is a critical issue for technicians when detecting faults with invisible near-infrared (850nm-1625nm) wavelengths that are used extensively in fiber-optic communications. Hand-held devices can be used to enable the fast identification of cable and port issues in traditionally difficult troubleshooting applications, saving time while also protecting the technician’s eyes from any chance of damage.
FiberLert easily detects active fiber signals for testing ports, cables and polarity.
Another big challenge for maintaining fiber optic connections is dirt, debris and damage. The majority of single-core fiber connectors use a ferrule manufactured from china, which while usually robust, can be subject to scratches or other damage which reduce or prevent data transmission. Even the smallest speck of dust invisible to humans can cause errors or total failure on a fiber-optic connection. Inspection tools and cleaning equipment are essential for technicians maintaining fiber networks. The best inspection cameras are designed for simplicity and efficiency. A great example features a multi-camera design, which enables technicians to apply a ‘live view’ to single fiber connector ferrules, as well as MPO trunks with up to 32 fibers. End-face condition assessments can be carried out as the technician moves from full trunk to individual end-faces using touchscreen gestures.
FI2-7300 screens when inspecting and automatically testing an MPO trunk connector with 32 fibers.
Technicians should also have lint-free fiber-optic cleaning kits with appropriate solvents to hand, to remove tough contaminants in an optical fiber cable network. Solvents are more effective than the traditional isopropyl alcohol (IPA) method used to dissolve the kind of contaminants found on the outside of optical fiber cables.
3. What is the fastest way for network technicians to locate faults and verify continuity or polarity issues when troubleshooting fiber-optic cables?
Speed is of the essence when attempting to locate a problem in a live network, which can be a difficult and time-consuming process when working with a complex network of fibers. Whether technicians are installing new fiber links or troubleshooting an existing network, a very useful tool for locating faults is a live optical fiber detector (such as Fluke Networks Fiberlert shown above) that enables operators to carry out basic tests on fiber to easily identify polarity issues and failed transceivers.
An Optical Time Domain Reflectometer (OTDR) is the ultimate tool for troubleshooting fiber-optic systems, particularly in enterprise and outside plant (OSP) environments. Hand-held opto-electronic instruments can test a complete fiber-optic link to ascertain its condition and performance capability. OTDRs are the only instruments that test components along the cable path, such as connection points, bends or splices, to check the cable’s capability from start to finish. Essentially, the equipment sends a light pulse into one end of the cable and receives a reflected signal sent back to the same OTDR port. Some of the light transmitted through the cable will scatter and some will be reflected and returned to the OTDR, indicating loss and distances to connectors or faults. This is measured by recording the time it takes for the signal to come back.
However, some OTDRs can be complicated to operate. It is critical for novices and experts alike to search for tools that simplify the process with, for example, an automated setup function or a built-in mapping system which can automatically identify issues in fiber-optic cabling.
The OptiFiber Pro EventMap greatly simplifies the interpretation of the measurement: here we see the OTDR at the bottom of the screen, connected to a designated launch fibre , shown in grey, then the installed fibre shown in black, with connectors identified as rectangular 'boxes' at each end, and finally the receive/tail fibre, again shown in grey.