The key physical parameters of fiber optic link

After the installation of fiber optic cabling system, it is needed to test the link transmission characteristics, including several most important test projects like link attenuation characteristics, connector insertion loss, return loss, etc. Following is a brief introduction of the measurements of the key physical parameters during the fiber optic cabling process.

The key physical parameters of fiber optic link:

Attenuation
1. Attenuation is the light power reduction in the fiber optic transmission.
2. Calculation of total attenuation of the fiber optic network: fiber LOSS is the ratio of the Power out of the fiber output end and the Power in of launched into the fiber.
3. The loss is proportional to the length of the fiber, so the total attenuation not only means the loss of fiber itself, but also reflects the length of the fiber.
4. Cable loss factor (α): In order to reflect the characteristics of the fiber attenuation, we introduce the concept of cable loss factor.
5. Attenuation measurements: As the fiber connected to the fiber optic light source and optical power meter will unavoidable take additional losses. Field test must carry on the test reference point setting (zero set). There are several methods for testing the reference point, these methods are mainly based on the link test object selection, in the fiber optic cabling system, since the length of the fiber itself is usually not long, so the test method will pay more attention to the connector and measurement of fiber optic patch cords, the method is more important.

Return Loss
The reflection loss, also known as return loss, refers to the backward reflection light relative to the ratio of the input number of decibels at the fiber optic connector, the return loss is larger the better, in order to reduce the reflection effect of light on the fiber light source and system.

The methods to improve return loss, try to use the fiber end surface is processed into spherical or oblique spherical is an effective way.

Insertion loss
Insertion loss is light signal in the optical fiber after through the connector, the output optical power relative to the input optical power ratio in decibels.
Insertion loss is smaller the better.
The insertion loss measuring method is the same with measuring method of attenuation.

In a word, to complete the measurement of an optical loss, a calibrated optical light source and a standard optical power meter is indispensable.

The Tips To Test Fiber Optic Fast Connector With Hand-held Testers

Prepare the fiber testers you need

1.Use a cable stripper to strip the outside coating of the cable to expose the active wire underneath. Usually, stripping a wire or cable involves scoring the coating to the cable to detach it so it slides away from the outside of the wire without damaging the wire.

2. Generally test every 10 fiber optic connectors need to re-manufacturing optical fiber, each test need to check the fiber If it is damaged.

3. Cut drop the protective layer of the cable as far as possible, instead of with a wire stripper, to reduce the damage of the fiber cable. When use a wire stripper, bent the fiber optical cable 60 degrees in four directions, check the fiber if it is intact. At present, many wire strippers are poor quality, easy to damage the fiber optic, must particularly stressed.

4. The use of imported fiber cleaver, such as Sumitomo FC-6S, complete the pressure optical fiber surface and keep the cutting surface clean, to ensure excellent cutting quality. Excellent cutting surface is flat with the end face of the tilt angle is less than 0.5 degrees and no glitches. Poor Cutting surface the end tilt angle is large and there are glitches. Burr fiber optic inserted into the fiber fast connector may appear broken fiber, fiber butt gap and so on, will leading to a loss of circuit of the products.

The attentions you should mind during the testing process
1. The end surface cleaning first with dust-free paper which is moistened with alcohol, then dry the end surface with dry dust-free paper.

2. Use a combination of fiber light source and optical power meter for testing, prepare the fiber patch cord to the light source, mind the end surface insertion loss less than 0.1dB. The flange test need to use high-quality flanges, the traditional 1-2yuan flange with poor quality, test dozens or hundreds of times, the parameters may deteriorate. Using wire jumper to do the fiber optic cable test, making optical fiber fast connector connected to the fiber under test. Mind the covered wire jumper end surface insertion loss below 0.1dB.

3.Regular cleaning flange ceramic sleeves and special swabs which are covered when test fiber optical connectors, using air-laid paper and ceramic ferrule end face of the fiber jumpers. When suspect flange and fiber jumpers pointer exception, can through the comparative analysis of replace flange and fiber jumpers. General fiber jumpers and flange allows mating cycles of 500 times, need to replace the damaged fiber jumpers and flange timely.

4. When the test index is unnormal, should pay attention to the fiber microbending whether is under the specified range, check the fiber is a broken or existence of a fiber cut.
5. Surface contamination will affect the test parameters, need to prepare the surface detector, check the end cleaning quality when abnormal.

The Method when test data is abnormal

1. Indicators in the 0.3-0.5dB, clean the end surface and retest.
2. Indicators above0.5dB, clean the end surface, re-prepare a test fiber and re-test.

How to Mechanically Install Fiber Optic Connectors

The role of fiber optic connectors is to give a connection or disconnection solution for a fiber optic link. To make the light power from the fiber optic transmitter successfully received by the receiver end, it is required to install the optical fiber connectors at both ends of and optical fiber stand. Install fiber optic connectors is a caution job that you should handle with much carefulness, otherwise there will cause a failure in the optical signals transmission.

The aim of installing fiber optic connectors is to provide a protection for the tripped fiber end in the connector ferrule in case that the cable entering the back of the connector body or prevent the fibers from moving back and fore within the connector body. Good installation will make it free of optical loss and connector or fiber damages.

There are both mechanical methods and chemical methods to fiber optic connector installation, which come in adhesives and polish, cleave and crimp, and fusion splicing the fiber pigtails. Fusion splicing belongs to chemical methods while the last two is for mechanical. Mechanical ways features both cost and time saving, which is suit for small qualities of fiber optic connectors installation, which is also be discussed in the article.

mechanically install fiber connectors

Mechanical Adhesives and Polish
This way can be simply called epoxy and polish, the two main steps indicated. Steps follow, use a Fiber cable stripper to strip the buffer coating and the plastic jacket from the fiber end. Inject the epoxy glue into the connector body until a small amount flows out of the ferrule end. Insert the stripped fiber end into the connector body and then place them into an oven to get heated. After 145j minutes, remove the assembly from the oven for cooling. After the connector is enough cool to handle, use a fiber optic scribe to gently scratch the excess fiber sticking out of the ferrule. Remove the fiber stub and use the finer polishing papers to polish the fibers.

In the reality practice of the fiber connector installations, you will find another type of connectors that already has the epoxy inside the connector body. With this connector type for the job, you can skip the step of injecting the epoxy, and follow the rest steps above to finish the job.

Mechanical Cleave and Crimp
Cleave and crimp is the simplest and the fastest way for the connector installations. Because this method is only for a special type of connector which has already has the polished optical fiber stub installed in the ferrule by the manufacturer. Step for installing these connectors is simple: After the jackets and buffer coating of the fiber cable are stripped by the technician, use a fiber optic cleaver to break off the fiber to within two degrees of 90 degrees at a specific length. Then insert the cleaved fiber end into the back of the connector until it contact the fiber stub within that have been cleaved at the factory, mechanical clamp will be activated automatically. Once the two cleaved fibers ends has holds together, use a crimp tool to crimp the back of connector
to the fiber jacks.

What you should note is that in the whole process of the two mechanical fiber connector installation method, you should make sure all the related tools such as the cable wire strippers, crimping tools, fiber optic cleavers involved should be with high quality. Because a mediocre or poor tool will make the connector poor or inoperative. This article is only about the mechanical method, if you are also interested in the chemical splicing pigtail ways, please pay continuous attention to my blog.

CCTV Tester Of Maintenance Equipments

In Closed circuit television (CCTV) installation, testing is very important to complete the project on agreed deadline and not to overspend or duplicate the work. And the CCTV tester is the useful tool for CCTV system, which is experiencing a leap in technology using digital techniques and the Internet. A CCTV tester is a device with a small screen and facilities to test coaxial cable, RJ45, cameras, PTZ, microphones and monitors. It is a handy tool in testing signal strengths and any signal short circuit. CCTV tester now had been developed and designed to be small, lightweight potable and comes with LCD monitor, so using a tool like this makes set up and debugging your CCTV system easier.

3.5 inch CCTV Security Tester STest-893 with PTZ Controller and Power Supply

No matter you are DIY Your home security system or working as a CCTV technician, CCTV tester is the tool to give you the ability to set field of view, adjust focus, pan, tilt, zoom, and troubleshoot power, video, and audio connections etc. From the CCTV tester you can know the current situation, including the details of CCD cameras, lenses, coaxial cables, fiber-optics, and system design. What’s more, CCTV tester is expanded to cover all video compression techniques used in the ever increasing assortment of digital video recorders (DVRs) available in the market. It also serves to clarify the technology of data networking.

There are various types of CCTV testers, and I would like to introduce the CCTV Security Tester STest-893 as an example.

CCTV Security Tester STest-893 with PTZ Controller and Power Supply Features:

3.5″TFT-LCD, 960 (H) × 240(V) resolution;
DC12V power output;
Audio input;
Adjustable brightness, contrast, color of LCD;
Video Level testing, video signals measured in IRE or mV;
Automatically identify and adapt the video mode of NTSC and PAL;
Colorbar Video signal generator, transmit/receive colorful images;
Support more than twenty kinds of PTZ controller protocols. For example, PELCO-P, PELCO-D, SAMSUNG, etc;
PPTZ address scanning, search up the ID of PTZ camera;
Capture the PTZ protocol to assist the setting personnel to find out the control protocol and therefore easily target the problematic equipment;
Support RS232 and RS485 interface, the rate 150-19200bps;
Powerful in testing LAN cable, measuring the connecting status and displaying the sequence of connection;
PTZ(P/L & Zoom) Control: Control the status of P/L, zoom in/out the camera, adjust the aperture, foci and setting parameters, run and call the preset;
Lithium Ion Polymer Batteries (3.7V DC3000mAh), more reliable, and work 15 hours;
Easy for use that the train is almost unnecessary.

CCTV tester can be used for displaying video, controlling PTZ, generating images, capturing data of RS485 and testing LAN cable etc. Its functions, easy operation, and convenient portability enable it simple for the contractor to install and maintain the video camera, promote working efficiency and cost-down the expenditure of the project. Fiberstore is a professional fiber optic testers supplier, you also can find other maintenance equipments like adsl testcable fault locator, etc.

Strip Cables’ Outside Coating With A Wire Stripper

Most cables are wrapped in what amounts to a protective tube around the wire to improve safety and extend the operating life of the cable. Cable stripper, also called wire stripper, is a tool used to strip the outside coating of a cable to expose the active wire underneath for installation. Usually, this tool is used when two wires need to be connected or when a connector needs to be applied to the end of a coated wire.

Original Miller Dual Holes Fiber Optic Stripper FO 103-D-250

Cable stripping tools are usually hand-held metal tools that look similar to pliers, except they feature a cutting end and stripping hole instead of a grip. Most cable strippers come with cable cutters already built into the tool. Other cable strippers may have specifically-sized holes that are designed to perfectly strip wires of varying sizes. Using a specially-sized cable stripper can make a proper cable stripping job easier to carry out. Professionals such as electricians or cable installation specialists often use size-specific cable strippers that are designed to strip a precise type of cable commonly used in their industries.

How To Use A Cable Stripper
Stripping a cable with a cable stripper is typically easy to do, and mistakes in stripping can be corrected easily. Older, brittle, or weathered wires inside a cable can make a successful stripping job more difficult than usual. Unless the amount of available cable is limited, a botched cable strip job can be remedied simply by clipping the badly stripped edge off with a wire cutter and re-stripping the cable.

What Types Of Wire Strippers
Cable strippers come in a variety of designs to support the diversity of their usefulness. Handheld designs are most convenient and inexpensive, but benchtop varieties are manufactured to assist in high-volume stripping applications. Articulation of the stripper ranges between manual, electrical, and pneumatic power sources.

A simple manual wire stripper is a pair of opposing blades much like scissors or wire cutters. The addition of a center notch makes it easier to cut the insulation without cutting the wire. This type of wire stripper is used by rotating it around the insulation while applying pressure in order to make a cut around the insulation. Since the insulation is not bonded to the wire, it then pulls easily off the end. This is the most versatile type of wire stripper.

Another type of manual wire stripper is very similar to the simple design previously mentioned, except this type has several notches of varying size. This allows the user to match the notch size to the wire size, thereby eliminating the need for twisting. Once the device is clamped on, the remainder of the wire can simply be pulled out, leaving the insulation behind.

How To Choose A Wire Stripper
The quality of a stripped wire is largely determined by the quality of the tooling selected. Properly-sized tools are the easiest way to provide a high-quality exposed conductor, and many wires are required to be labelled with gauge information. Another determination of wire quality includes the strip length. Devices like switches and receptacles will have a strip gauge, and automated machines will have a clear adjustment mechanism to ensure accurate wire and strip lengths.

Fiberstore provides a range of fiber tools, our complete line of fiber optic strippers feature more than 40 products. To check which of our wire strippers will suite your particular wire sizes, scroll down to view all our wire strippers or contact our sales. And if you can’t find it here, we can custom build one for you!