Account Options Sign in. Government Printing Office , - Weights and measures. Selected pages Table of Contents. Contents Bibliographic abbreviations. Length and diameter measurements. Dimensional measuring instrument.
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Optics in MedicineVIDEO ON THE TOPIC: Optical Instruments: Crash Course Physics #41
Modal Conditioning For Multimode Fibers. Most standards for multimode fiber tests includes some modal conditioning to create standardized test conditions to ensure repeatable measurement results.
The usual method is to use a source whose output meets a standard criteria, coupled to a reference launch cable, on which a mandrel wrap is used to remove higher order modes. Mode conditioners are also available from test equipment manufacturers. Standards may have different methods, including different requirements for different fibers.
Reference launch cables using bend-insensitive fiber may not respond to the usual methods of mode conditioning and are generally not recommended for launch cables but since most multimode fiber is now BI fiber, this may not be a relevant requirement. More information on modal effects on multimode fiber measurements and mandrel wraps is here on the FOA Guide website and in the FOA textbook on testing.
Component Testing. Manufacturers of fiber optic components do extensive testing to qualify their component designs, verify manufacturing procedures and test the products before shipment to customers.
Fibers are tested for dimensions core and cladding size, ovality and concentricity, performance attenuation coefficient, bandwidth or dispersion, physical characteristics strength, flexibility, etc.
Cables add even more stringent environmental tests. Connectors and splices are tested in large batches to determine average losses expected in normal installations. Environmental testing mirrors that for cables, but may add tests for special applications like vibration for use on vehicles, ships or aircraft. Transceivers, WDMs, fiber amplifiers and other fiber optic components will have testing for both fiber-related performance and electrical performance.
Fiber Characterization. This is especially important for older fiber optic cable plants where network speeds are being upgraded because the older fibers were manufactured to different standards for slower networks.
You need a cable to measure the output power of the source for calibration of "0 dB" loss. In order to measure the loss of the connectors you must mate them to a similar, known good, connector. This is an important point often not fully explained. When we say connector loss, we really mean "connection" loss - the loss of a mated pair of connectors.
Thus, testing connectors requires mating them to reference connector which must be high quality connectors themselves to not adversely affect the measured loss when mated to an unknown connector. Testing with reference cables on each end simulates a cable plant with patchcords connecting to transmission equipment. Topic: Fiber Optic Testing. Fiber Optic Testing Testing is used to evaluate the performance of fiber optic components, cable plants and systems. As the components like fiber, connectors, splices, LED or laser sources, detectors and receivers are being developed, testing confirms their performance specifications and helps understand how they will work together.
Designers of fiber optic cable plants and networks depend on these specifications to determine if networks will work for the planned applications. For the purposes of this particular page, we will focus on the installed cable plant, but other pages on this website will cover many more aspects of fiber optic testing.
After fiber optic cables are installed, spliced and terminated, they must be tested. For every fiber optic cable plant, you need to test for continuity and polarity, end-to-end insertion loss and then troubleshoot any problems.
If it's a long outside plant cable with intermediate splices, you will probably want to verify the individual splices with an OTDR test also, since that's the only way to make sure that each splice is good.
If you are the network user, you may also be interested in testing transmitter and receiver power, as power is the measurement that tells you whether the system is operating properly.
Testing is the subject of the majority of industry standards, as there is a need to verify component and system specifications in a consistent manner. Perhaps the most important test is insertion loss of an installed fiber optic cable plant performed with a light source and power meter LSPM or optical loss test set OLTS which is required by all international standards to ensure the cable plant is within the loss budget before acceptance of the installation. See Jargon and Test Instruments to see a description of these instruments.
Getting Started Even if you're an experienced fiber optic tech, make sure you remember these things. Have the right tools and test equipment for the job. Optical inspection microscope, X video scope recommended Source and power meter, optical loss test set OLTS or test kit with proper equipment adapters for the cable plant you are testing.
Know how to use your test equipment Before you start, get together all your tools and make sure they are all working properly and you and your installers know how to use them.
It's hard to get the job done when you have to call the manufacturer from the job site on your cell phone to ask for help. Try all your equipment in the office before you take it into the field. Use it to test every one of your reference test jumper cables in both directions using the single-ended loss test to make sure they are all good. If your power meter has internal memory to record data be sure you know how to use this also. You can often customize these reports to your specific needs - figure all this out before you go it the field - it could save you time and on installations, time is money!
Make sure you have cable layouts for every fiber you have to test and have calculated a loss budget so you know what test results to expect. Prepare a spreadsheet of all the cables and fibers before you go in the field and print a copy for recording your test data.
You may record all your test data either by hand or if your meter has a memory feature, it will keep test results in on-board memory that can be printed or transferred to a computer when you return to the office. A note on using a fiber optic source : eye safety. Fiber optic sources, including test equipment, are generally too low in power to cause any eye damage, but it's still advisable to check connectors with a power meter before looking into it.
Besides, most fiber optic sources are at infrared wavelengths that are invisible to the eye, making them more dangerous. Connector inspection microscopes focus all the light into the eye and can increase the danger. Visual Inspection Visual Tracing Continuity checking with a visual fiber tracer makes certain the fibers are not broken and to trace a path of a fiber from one end to another through many connections, verifying duplex connector polarity for example. It looks like a flashlight or a pen-like instrument with a light bulb or LED source that mates to a fiber optic connector.
Attach the fiber to test to the visual tracer and look at the other end of the fiber to see the light transmitted through the core of the fiber. If there is no light at the end, go back to intermediate connections to find the bad section of the cable. A good example of how it can save time and money is testing fiber on a reel before you pull it to make sure it hasn't been damaged during shipment.
Look for visible signs of damage like cracked or broken reels, kinks in the cable, etc. For testing, visual tracers help also identify the next fiber to be tested for loss with the test kit.
When connecting cables at patch panels, use the visual tracer to make sure each connection is the correct two fibers! And to make certain the proper fibers are connected to the transmitter and receiver, use the visual tracer in place of the transmitter and your eye instead of the receiver remember that fiber optic links work in the infrared so you can't see anything with your eye anyway - but you may be able to use your digital camera or cell phone camera.
The red laser light is powerful enough for continuity checking or to trace fibers for several kilometers, identify splices in splice trays and show breaks in fibers or high loss connectors. It's most important use is finding faults in short cables or near the connector where OTDRs cannot find them. You can also use this gadget to visually verify and optimize mechanical splices or prepolished-splice type fiber optic connectors.
By visually minimizing the light lost you can get the lowest loss splice. In fact- don't even think of doing one of those prepolished-splice type connectors without one.
No other method will assure you of high yield with those connectors. A note on VFL eye safety. VFLs use visible light. You will find it uncomfortable to look at the output of a fiber illuminated by a VFL. That's good, because the power level is high and you should not be looking at it. When tracing fibers, look from the side of the fiber to see if light is present.
Visual Connector Inspection by Microscope Fiber optic inspection microscopes are used to inspect connectors to confirm proper polishing and find faults like scratches, polishing defects and dirt. They can be used both to check the quality of the termination procedure and diagnose problems. A well made connector will have a smooth , polished, scratch free finish and the fiber will not show any signs of cracks, chips or areas where the fiber is either protruding from the end of the ferrule or pulling back into it pistoning.
Microscopes are also used to inspect connectors before mating or testing them to ensure the connectors are clean - no dirt or contamination. The process is to inspect - clean - then inspect again to confirm proper cleaning. Repeat as necessary. The magnification for viewing connectors can be 30 to power but it is best to use a medium magnification.
The best microscopes allow you to inspect the connector from several angles, either by tilting the connector or having angle illumination to get the best picture of what's going on. Check to make sure the microscope has an easy-to-use adapter to attach the connectors of interest to the microscope. Video readout microscopes are now available that allow easier viewing of the endface of the connector and some even have software that analyzes the finish.
While they are much more expensive than normal optical microscopes, they will make inspection easier and greatly increase productivity.
The microscope will concentrate any power in the fiber and focus it into your eye with potentially hazardous results. Some microscopes have filters which remove infrared light from sources to be safe.
More on Visual Inspection. Optical Power - Power or Loss? The power output of a transmitter or the input to receiver are "absolute" optical power measurements, that is, you measure the actual value of the power. Loss is a "relative" power measurement, the difference between the power coupled into a component like a cable, splice or a connector and the power that is transmitted through it.
This difference in power level before and after the component is what we call optical loss and defines the performance of a cable, connector, splice, etc. Even an OTDR described below measures optical power to measure loss. It's important to have enough power, but not too much. Too little power and the receiver may not be able to distinguish the signal from noise; too much power overloads the receiver and causes errors too.
Measuring power requires only a power meter most come with a screw-on adapter that matches the connector being tested , a known good fiber optic cable of the right fiber size, as coupled power is a function of the size of the core of the fiber and a little help from the network electronics to turn on the transmitter.
Refer to the instructions that come with the test equipment for setup and measurement instructions and don't wait until you get to the job site to try the equipment, try it in the office first! That can be at the receiver to measure receiver power, or using a reference test cable tested and known to be good that is attached to the transmitter to measure output power.
Set the power meter for the matching wavelength and note the power the meter measures. Compare it to the specified power for the system and make sure it's enough power but not too much.
It is important to remember that dB is for measuring loss, dBm is for measuring power and the more negative a number is, the higher the loss.
Set your zero reference before measuring loss and check it occasionally while making measurements. More on measuring Power.
The Fiber Polarity Tester FPT is a programmable fiber polarity testing instrument that can quickly and accurately measure the polarity for up to 72 channel MTP assemblies. Search our comprehensive database of resources, including technical papers, best practices, tips, FAQs, and more. At FOC, we are contacted daily as a resource for test and inspection support for fiber optic cable In standard Singlemode cable assembly, the two wavelengths used for Insertion Loss testing are The ferrule hole bore must be slightly larger in diameter than the fiber to allow the fiber to be
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ImageMaster HR brochure Download. The equipment is modular and upgradeable to allow for custom configuration as test requirements change. The instrument can be configured for testing optical systems with the object at infinity or object and image at finite conjugates. The accuracy of the measurement is traceable to international standards.
Optical Test Equipment
RSVP Now. View Our Service Certifications. LA: Jan This high level of training, sophisticated equipment, and scientific standards come together to make our optical service department so outstanding. A measurement of contrast, Modulation Transfer Function, or MTF, is the most widely used scientific method of describing lens performance and the criteria by which we measure the image quality of lenses.
Not a MyNAP member yet? Register for a free account to start saving and receiving special member only perks. Since the early part of this century the manufacturing of optical components and systems has changed dramatically throughout the world, both in the types of products that are made and in the approach that is taken to making them. Once devoted entirely to passive image-forming components such as lenses and mirrors and to the instruments made from them, the industry now also manufactures a wide range of active elements such as lasers and optical sensors. Until recently, the industry depended heavily on a craftsman-style approach to manufacturing, with much of the work being carried out on an order-by-order basis by very small businesses. As new mass consumer markets have emerged that rely on optical technology—such as compact disk CD players and laptop computer displays—the implementation of high-volume mass-manufacturing techniques similar to those of the electronics industry has revolutionized this segment of the optics industry. To take just one example of this new manufacturing technology, more than million diode lasers are now produced each year, on highly automated production lines. The availability of these inexpensive diode lasers has revolutionized entertainment in CD players , made high-quality printing affordable for small businesses and home users in laser printers , and made possible numerous other new products that together account for hundreds of billions of dollars in global business revenue each year. These changes in manufacturing are exciting, but they are reflected most prominently in the globalization of the optics industry, rather than in the domestic development of U.
Keysight Technologies, Inc. The new modules offer engineers additional price-performance options based on output power, tuning speed, wavelength accuracy and repeatability. Whether engineers need to verify the design of demanding optical components or adjust more wavelength-selective switches per hour, or they simply need a stable, tunable optical source, the xx family of tunable lasers offers a suitable model.
PCE Instruments PCE is an international supplier of test instruments, tools and equipment for measuring, weighing and control systems. Founded by German engineers nearly two decades ago, PCE offers more than test instruments with applications in industrial engineering and process control, manufacturing quality assurance, scientific research, trade industries and beyond. In addition, PCE can provide custom test instruments on demand. PCE serves customers from government, industry and academia in diverse fields such as acoustical engineering, aerospace, agriculture, archaeology, architecture, automotive, aviation, bioengineering, building inspection, chemistry, civil engineering, computer science, construction, data acquisition, education, electrical engineering, energy, environmental science, food processing, forensics, forestry, geology, government, horticulture, HVAC, hydrology, industrial hygiene, law enforcement, library science, logistics, machining, maintenance, manufacturing, materials science, mechanical engineering, metal working, meteorology, military, mining, nondestructive testing NDT , occupational health and safety, oil and gas, pharmaceuticals, property management, pulp and paper, physics, robotics, structural engineering, supply chain, transportation, tribology, veterinary science, water treatment, welding, woodworking and more. Test instruments can be found in research laboratories as well as in places like automobile repair shops, construction job sites and manufacturing facilities. Test instruments are used in trade industries for troubleshooting as well as for routine inspections of systems and equipment. Everyday consumers also need accurate, affordable test instruments for evaluating home energy efficiency, monitoring wind conditions for outdoor recreational activities, checking soil moisture levels in the garden, and more. For these types of applications, PCE Instruments offers a number of easy-to-use test instruments — no expert knowledge required. PCE's devices are of the highest industry standards, and are used for quality control and product testing in industrial settings, scientific research facilities, commercial businesses, government institutions, professional sports and recreation venues, and military operations. In addition, PCE's test instruments may be used in education for classroom demonstrations and laboratory tests. Electricians use PCE test instruments for assessing electrical installations in their daily work.
PCE Instruments UK: Test Instruments
Account Options Sign in. Government Printing Office , - Weights and measures. Selected pages Page Title Page. Table of Contents. Contents Length and diameter measurements. Length and diameter measurements. Calibration of line standards of length.
TEST SOLUTIONS CENTER
Optical test equipment or optical measuring instruments are used to measure and characterize the physical properties of light. The insatiable demand for higher capacity in communication networks has fueled the need for highly precise optical test solutions. In addition, precision optical measurements are essential to optical research applications for biophotonics, environmental sensing, and consumer products. For more than thirty years, Yokogawa formerly Ando has delivered quality, consistency, ease of use, and market leadership for optical test applications. An Optical Spectrum Analyzer or OSA is a precision instrument designed to measure and display the distribution of power of an optical source over a specified wavelength span. An OSA trace displays power in the vertical scale and the wavelength in the horizontal scale. An optical time domain reflectometer OTDR is a precision instrument used to locate events or faults along a fiber link, typically within an optical communications network. An Optical Wavelength Meter measures the peak wavelength s of an optical signal with extreme picometer and sub picometer accuracy. A modular test platform with a wide selection of modules allows optimal configuration of test solutions for optical component and network systems manufacturing.
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