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Top 10 Optical Time Domain Reflectometer Brand & Manufacturers

This section provides a list of the top 10 Optical Time Domain Reflectometer manufacturers, Website links, company profile, locations is provided for each company. Also provides a detailed product description of the Optical Time Domain Reflectometer, including product introduction, history, purpose, principle, characteristics, types, usage and purchase precautions, etc.

Manufacturers (Ranking in no particular order)

Aikosfo Communication Technology (Beijing) Co., Ltd.
Aikosfo Communication Technology (Beijing) Co., Ltd.
Address: Floor 25, Building A, Tianzuo International Center Office Building 1, No. 12, Zhongguancun South Street, Haidian District, Beijing
Company website: https://www.exfo.com/en
Company Overview
EXFO was founded in 1985 by Germain Lamonde, who successfully transformed himself from an engineering student to an entrepreneur, and the company soon became an innovator in the field of fiber optic testing. EXFO has embarked on a journey to become a global expert in network testing, monitoring and analysis. EXFO develops smarter testing, monitoring and analysis solutions for the global communications industry. EXFO is a trusted advisor, and its customers include fixed and mobile network operators, hyperscale data centers, and leaders in production and R&D. EXFO provides customers with good network performance, service reliability and user experience insights. Backed by 35 years of innovation, EXFO combines equipment, software and services in a novel and unique way, enabling customers to upgrade to 5G, cloud native and fiber optic networks more quickly and reliably. EXFO is an expert in testing, monitoring and analysis for the communications industry. Over the past 35 years, EXFO has continuously led the innovation of solutions and technologies. 95% of the world's major operators use EXFO's solutions, making it a global fiber optic testing solution provider. EXFO carefully builds end-to-end solutions that cover various applications from 0-7 layers, from the network core to the user, and from the laboratory to the field. EXFO's products can help you provide high-quality services quickly and with high quality. EXFO's high-performance, easy-to-use handheld instruments are designed to meet your needs and help you quickly and efficiently assess the quality of your network and services. They include service assurance platforms, field network test instruments, and lab and manufacturing test equipment.
Viagra Communications Technology (Beijing) Co., Ltd.
Viagra Communications Technology (Beijing) Co., Ltd.
Address: Room 1, 17, 1501, 12th Floor, Building 1, No. 38, North East Third Ring Road, Chaoyang District, Beijing
Company Overview
VIAVI is a diversified, colorful and technology-savvy company that has strategically executed many key technology acquisitions over the years, including Cobham, Agilent, Arieso, Network Instruments, OCLI, RPC Photonics, 3Z Telecom and Triliteric to advance a very broad range of products. Together with more than 350 global channel partners, VIAVI sells an extremely broad portfolio of products to global leaders in networking, communications and electronics technology. VIAVI not only provides individual products, but also works with customers to solve key issues that affect users, such as quality of service. For more than 50 years, spectrum analyzers have been the analysis and measurement tool for almost all forms of radio and fiber optic communications. Spectrum analysis provides the visibility needed to unlock the potential of 5G wireless network infrastructure by quantifying the signal behavior of frequencies. With an unwavering commitment to emerging technologies and customer satisfaction, VIAVI has created a portfolio of RF and spectrum analyzers and accessories at various price points. Rugged, integrated spectrum analysis tools extend the best accuracy and feature set from the lab to the field. Through use cases, VIAVI is able to help customers discover opportunities to use data and analytics to improve their business. That’s why VIAVI is at the forefront of every area where it delivers solutions, including game-changing technologies like 5G, fiber optics, and 3D sensing. VIAVI enables service providers and IT organizations to manage the network lifecycle of complex 5G and fiber optic networks with intuitive instruments, systems, and technologies. Knowledge in light management and optical coatings helps protect the world’s banknotes from counterfeiters, enhances the colors you see, and supports advanced technologies like 3D sensing.
Yokogawa Electric (China) Co., Ltd.
Yokogawa Electric (China) Co., Ltd.
Address: Room 1801, Tower B, The Place, 100 Zunyi Road, Changning District, Shanghai
Company Overview
Since its establishment in Tokyo, Japan in 1915, Yokogawa Electric Group has 92 subsidiaries in 59 countries and regions around the world. It is one of the world's most professional multinational companies in the industrial control industry. Yokogawa Electric (China) Co., Ltd. aims to win the trust of customers with high-quality products and excellent services, and create value with customers from the perspective of customers. The business goal of "Yokogawa Electric" is to achieve "sound and profitable management", think about what customers think, create and add value for users based on advanced technology, help users create effective industry mechanisms; open up broader development space and create better development opportunities for users' businesses; and become a trustworthy enterprise for partners by providing users with the best solutions and perfect services. The main businesses of "Yokogawa Electric" include: relying on Yokogawa Electric's rich customer resources in China to promote and sell Yokogawa's various industrial automatic control products and instruments; introducing Yokogawa's internationally advanced equipment, technology and management experience to the majority of users; relying on advanced market planning and awareness, scientific management and service system, and with the huge resources and support of the head office as a backing, providing various solutions to serve the majority of Yokogawa users.
Beijing Xinwei Technology Co., Ltd.
Beijing Xinwei Technology Co., Ltd.
Address: 7th Floor, Hongyun Building, No. 3 Shuangqing Road, Haidian District, Beijing
Company Overview
ShinewayTech was founded in 2002. It is a high-tech enterprise with high vitality and high innovation, and is developing rapidly in the field of global communication testing and operation and maintenance. At present, it has wholly-owned companies in Beijing, Hefei and Dallas, USA, with more than 200 employees. Its products are sold in nearly 100 countries and regions on six continents around the world, and it has a wide and good market reputation. Beijing Shineway Technology Co., Ltd. was listed on China's New Third Board in 2008 (stock code: 430038). Now it has a strong R&D, technical support and service team. It is a long-term and stable professional supplier for private network customers such as the three major domestic telecom operators, power, radio and television, and the military, and ranks among the top three in the optical communication testing market in many countries and regions. Based on the company's core technology, as well as extensive market coverage and customer recognition worldwide. As a national high-tech enterprise, a key enterprise of Beijing's Gazelle Plan, and a Haifan enterprise, the company has R&D centers, production bases, global marketing and service centers in the core area of Beijing Zhongguancun, Hefei National High-tech Zone and Dallas, USA, and has many offices and business partners at home and abroad. The company can provide innovative and competitive communication testing products and operation and maintenance solutions to help customers cope with today's and future's rapid growth challenges and effectively reduce operating costs. In 2004, Xinwei Technology launched a handheld OTDR with 5 patented technologies. Since then, the company has continuously developed a rich communication testing and application product line, including intelligent light source/optical power/optical loss tester, GE/10GPON optical power meter, single-core/FTTH/ribbon fiber fusion splicer, WDM network tester, intelligent fiber end face detector, fiber connector cleaner, 6G spectrum analyzer, antenna feeder tester, RF power meter/spectrum power meter, network cable tester, GE/10G tester and more than 30 series and more than 100 models, covering the three major communication infrastructures of optical fiber network, wireless network and IP Ethernet. At the same time, it can also provide a full range of solutions such as 3D visualization intelligent operation and maintenance system, intelligent optical cable monitoring system, Internet of Things optical fiber wiring management system, computer room dynamic environment monitoring system, special application optical fiber sensing system, etc., making the company one of the few comprehensive original manufacturers that can provide one-stop services in the field of network intelligent testing, operation and maintenance and management. Xinwei Technology will continue to be committed to bringing customers products and solutions with better experience, easier use, smarter and higher quality, and to safeguard the informatization and intelligence of global networks!
Anritsu Communication Technology (Shanghai) Co., Ltd.
Anritsu Communication Technology (Shanghai) Co., Ltd.
Address: Room 2301-2303, 23F, Building 2, No. 391, Guiping Road, Xuhui District, Shanghai
Company Overview
Founded in 1895, Anritsu is a global supplier of innovative electronic measurement solutions with a history of more than 110 years, providing solutions for existing and next-generation wired and wireless communication systems and operators. The company is headquartered in Japan, with R&D centers and production bases in the United States, Japan, France, the United Kingdom, Denmark and other countries, and sales are spread all over the world. Anritsu's products cover the following areas: microwave/RF testing, wireless communication testing, industrial automation, digital transmission testing, IP testing, optical communication testing, information terminals, electronic components, etc. Among them, the business volume in the field of test and measurement accounts for about 70% of the company's total business each year. In the fields of consistency testing, signaling testing, and production testing of 3G/LTE terminals, Anritsu is at the advanced level in the industry. In addition, in optical communication testing and high-speed bit error testing, such as optical time domain reflectometers, optical spectrum analyzers, transmission testers, 100GE testing, 28G/56G bit error testing, etc., it is also at the advanced level in the industry; in the field of RF/microwave handheld test instruments, Anritsu is in the leading position in the industry.
Nanjing Jilong Fiber Optic Communication Co., Ltd.
Nanjing Jilong Fiber Optic Communication Co., Ltd.
Address: Room 401, Building 14-1, Xingzhihui Business Garden, No. 19 Xinghuo Road, Jiangbei New District, Nanjing, Jiangsu Province
Company website: https://www.jilongtx.com/
Company Overview
Nanjing Jilong Fiber Optic Communication Co., Ltd. (abbreviated as: Jilong Communication/Nanjing Jilong) was founded in 1993 and has a 30-year brand history. Jilong is a domestic high-tech enterprise and a global professional supplier of optical communication products and solutions. It has developed four major product systems, including "optical fiber splicing, OTDR, measuring instruments, and optical fiber tools", aiming to provide global users with a full range of complete optical communication solutions. Back in the 1990s, all the splicers on the domestic market were foreign brands, with a price of about 300,000 yuan. In 1993, the founding team of Jilong broke the monopoly of foreign fusion splicing technology and took the lead in developing and launching the domestic optical fiber fusion splicer KL-100, taking a crucial step from scratch in the development of domestic fusion splicers. Its price was only half of that of Japanese brands. Later, it began to launch various models of optical fiber fusion splicers, and the product cost continued to decrease. The scale of Jilong Company continued to grow. Not only that, Jilong Communications can also be called the "Huangpu Military Academy of the Domestic Fusion Splicer Industry". With the open sharing of Jilong's many invention patents and utility model patents, it has promoted the rapid rise of domestic fusion splicers. At the same time, it has also made great contributions to the domestic optical fiber replacement, FTTH fiber-to-the-home, domestic 4G, 5G network construction and the development of the optical communication industry. In 2012, the construction of Jilong Industrial Park was completed and put into use. The park covers an area of 21 acres and a total construction area of more than 14,000 square meters. It has a standardized office building, a modern production workshop, an industry-leading laboratory, and an intelligent warehousing system. The company has more than 150 employees, including 4 engineers with senior professional titles, 11 with master's degrees or above, 86 technical management talents of various types, and more than 60% of the company's employees have bachelor's degrees. In the past 30 years, Jilong has broken its own new records again and again, and has obtained more than 155 related patents in total. It is a listed company in the field of domestic fusion splicers, the first manufacturer of domestic fusion splicers to export overseas, and a domestic high-tech enterprise certification. It participated in the drafting of the new national standard for optical fiber fusion splicers "GB/T 17570-2019 General Specifications for Optical Fiber Fusion Splicers". The laboratory was recognized as the "Nanjing Communication Equipment Manufacturing Engineering Technology Research Center"... The company has passed the ISO9001 quality system certification, and its products have passed the EU CE safety certification and Rosh certification. At present, Jilong Communication has formed a cross-regional business structure with Nanjing as the management headquarters, Shanghai as the R&D center, and Bengbu as the production base, and has strong independent R&D and production capabilities. As a pioneer of domestic fiber fusion splicer brands, the fully automatic fiber fusion splicer developed and produced by Jilong Communication has independent intellectual property rights for both software and hardware design. Among them, high-quality models such as KL-360T and 280T use Jilong's new self-developed fiber core alignment technology. The fiber core can be clearly seen by the naked eye during the fusion process, and the application of this technology effectively achieves ultra-low loss fusion. Not only that, Jilong Communication has also made efforts in the field of OTDR. Since the advent of the first generation of OTDR--KL-6210 in 2010, Jilong has continued to deepen research and development in OTDR, striving to make domestic OTDRs with excellent performance. In 2022, Jilong's second-generation OTDR KL-6200, a multi-functional and intelligent machine, will be launched, allowing domestic OTDRs to be comparable to imported machines. In 2024, Jilong's third-generation OTDR, the high-precision all-round KL-6300, will be on the market. Today, Jilong's product services have covered areas such as fiber optic communication construction, measurement and maintenance, detection and cleaning, greatly reducing customer selection costs. At present, Jilong's products are widely used in communications, radio and television, railways, petrochemicals and other fiber optic network projects as well as scientific research institutes, and its products and services cover Europe, North America, Australia, South America and other regions.
Huaxing Xinrui Communication Technology Group Co., Ltd.
Huaxing Xinrui Communication Technology Group Co., Ltd.
Address: Hejian Economic and Technological Development Zone, Cangzhou City, Hebei Province
Company Overview
Huaxing Xinrui Communication Technology Group is located in Hejian City, the center of the Beijing-Tianjin-Shijiazhuang triangle and the national communication equipment production base. It is a "specialized, sophisticated and innovative" high-tech private enterprise group specializing in the research and development, production, sales, service and construction of optoelectronic communication equipment and smart home-smart door lock industry, involving five major business sectors including instrumentation, optoelectronic communication products, cable accessories, communication engineering design and construction, and smart Internet of Things. Huaxing Xinrui Communication Technology Group Co., Ltd. is the parent company of Huaxing Xinrui Communication Group. The company is located in the (provincial) Economic and Technological Development Zone of Hejian City, Hebei Province. The company has a construction area of more than 40,000 square meters and has advanced automated production equipment and high-end testing equipment. It has many subsidiaries, and its market covers 32 provinces, municipalities and autonomous regions across the country. Among them, the marketing center has 7 regional offices and multiple provincial offices. On the basis of "ISO9001:2008 Quality Management System", "IS014001:2004 Environmental Management System" and "OHSAS18001:2007 Occupational Health and Safety Management System" certification, the company has introduced advanced information management to strengthen the company's management and control capabilities. The company insists on implementing 5S management, forming a good development situation with smooth and efficient production and operation, standardized and orderly internal control, outstanding team building and rich and colorful corporate culture. The company is currently a high-quality supplier of China Unicom, China Mobile and China Telecom, the three major telecommunications network operators, China Broadcasting Network, State Grid, National Defense Communications, Railway Communications and many domestic and foreign network communication companies. At the same time, the company has won unanimous praise from all partners for its excellent product quality and high-quality and efficient professional services.
Zhejiang Xince Communication Co., Ltd.
Zhejiang Xince Communication Co., Ltd.
Address: 1-2 Floor, No. 2 Chuangye Building, No. 128 Shuanglian Road, Haining Economic Development Zone, Jiaxing City, Zhejiang Province
Company Overview
Zhejiang Xince Communication Co., Ltd., formerly known as Shanghai Xince Communication Technology Co., Ltd., was founded in 2004. For 17 years, Xince Communication has been adhering to the business philosophy of "trust as the basis and testing as the essence", and has been serving the vast number of professional market customers with honest management and superb technology. At present, there are more than 400 agents in the country, covering operators such as China Telecom, China Mobile, China Unicom, and also including private network customer groups. Overseas, Xince Communication's products have spread to more than 30 countries and regions, won a good reputation and established a complete sales and after-sales service system. In the market, the company listens to the opinions and suggestions of customers and partners, predicts and identifies needs, and continuously invests and innovates in manufacturing technology, R&D and design engineering to make products closer to market demand. Xince Communication has two main businesses - optical network testing, monitoring, sensor service support and electromagnetic environment safety detection solutions. Xince Communication already has more than 40 patents (including inventions, utility models and appearance patents) and more than 20 software copyrights. The annual R&D investment of more than 15% of sales is committed to building a strong R&D, technical support and service team to meet the needs of global customers. Since its establishment, the company has attached great importance to R&D and has cultivated a complete R&D team with continuous investment. The company uses self-developed chips to produce red light sources, uses multi-touch technology to develop and design large-screen optical time domain reflectometers, integrates optical power meters, red light sources, network cable tests, and lighting modules on the same instrument, etc. These product innovations reflect the company's sensitive market sense and complete R&D system. In 2013, an electromagnetic radiation laboratory was established. In the field of environmental monitoring, the company's unique electromagnetic environment online monitoring technology has been widely used. On the basis of focusing on cultivating its own R&D team, the company attaches great importance to industry-university-research cooperation, and actively cooperates with scientific research institutions such as Tsinghua University and Zhejiang University to enhance its own R&D capabilities. Through the accumulation of experience and professional knowledge, Xince Communication has become a valuable partner of customers; and strives to create an ideal working environment for employees and be a responsible corporate citizen.
Shanghai Guangwei Communication Technology Co., Ltd.
Shanghai Guangwei Communication Technology Co., Ltd.
Address: 6th Floor, Xin'an Building, Building 13, No. 99 Tianzhou Road, Caohejing New Technology Development Zone, Xuhui District, Shanghai
Company Overview
Guangwei was founded in Shanghai in 1994. Its full name is Shanghai Guangwei Communication Technology Co., Ltd. It has been committed to the field of optical communication construction and maintenance for many years. "Let's go in the grandway!" Guangwei firmly believes that information is the foundation for building a future society. In order to protect this foundation, it continues to innovate, open up cooperation, and has more than 100 patents and software copyrights. Its products also have multiple patents and multiple quality certification system certifications in China, Europe, the United States, etc. Guangwei has multiple companies, outlets and branches, serving the whole country and even the world.
Beijing Opwell Technology Co., Ltd.
Beijing Opwell Technology Co., Ltd.
Address: Room 1445, 6th Floor, Building A, Information Building, No. 28, Shangdi Xinxi Road, Haidian District, Beijing
Company website: http://www.opwill.com
Company Overview
Beijing Opwell Technology Co., Ltd. (OPWILL) was established in October 2007 in Beijing Zhongguancun National Independent Innovation Demonstration Zone. The entrepreneurial team is from internationally renowned communication instrument or equipment manufacturers, and the core personnel have high-level R&D capabilities and rich market experience. Since its establishment, OPWILL has been committed to providing users with accurate, reliable and convenient communication test solutions. The company's products cover the fields of optical fiber, transmission, data, synchronization and wireless, and are widely used in the production, installation and maintenance of communication equipment, serving communication equipment manufacturers, operators, private network users and communication construction and maintenance service companies. OPWILL has obtained 28 software copyrights, 36 patents and 2 registered trademarks. Many of the company's products have been recognized as new technologies and new products in Zhongguancun National Independent Innovation Demonstration Zone. In 2012, the company's next-generation SDH transmission tester products were supported by the Technology Innovation Fund Project for Science and Technology-based Small and Medium-sized Enterprises. In 2013, it participated in the "Broadband High-speed Optical Signal Analyzer Equipment Development" project of the Ministry of Science and Technology's National Major Scientific Instrument and Equipment Development Special Project, responsible for the research and development of 100G Ethernet products, representing the advanced technology of 100G rate in China. In 2014, the company's PTN test instrument project based on 4G mobile Internet backhaul test technology was supported by the Beijing Municipal Science and Technology Commission's "Capital Design Improvement Plan" project. The company's 100GE, 100GOTN, 43GOTN, 10GOTN/PTN, 10GE and other products have met the relevant international and domestic standards. OPWILL provides 10G rate test solutions in China, and in the field of communication testing with a rate of more than 40G, OPWILL also provides corresponding solutions. At present, OPWILL is a partner of China's three major operators: 8 products have been shortlisted for China Mobile; 3 OTDRs have obtained a large supply share of China Telecom; 5 products have been shortlisted for China Unicom. OPWILL communication test instruments have been widely used by China's three major operators and have won a good reputation among users. OPWILL not only serves major domestic operators, equipment manufacturers, private network users and a large number of communication service contractors, but also has been exported to more than 30 countries and regions in the world. The main customers include internationally renowned equipment manufacturers such as ERICSSON and FiberHome, as well as internationally renowned operators such as VODAFONE and BT. OPWILL has become a supplier of mid-to-high-end communication test instruments and communication test solutions!

Categories related to Optical Time Domain Reflectometer

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Information

Optical Time Domain Reflectometer Information

What is Optical Time Domain Reflectometer

An optical time-domain reflectometer (OTDR) is an optoelectronic instrument used to characterize an optical fiber. It injects a series of optical pulses into the fiber under test and extracts, from the same end of the fiber, light that is scattered (Rayleigh backscatter) or reflected back from points along the fiber. The scattered or reflected light that is gathered back is used to characterize the optical fiber. The strength of the return pulses is measured and integrated as a function of time, and plotted as a function of the length of the fiber.


History of Optical Time Domain Reflectometer

The development of OTDR is closely related to the progress of fiber optic technology. As the demand for fiber optic communication increased, the need for instruments to accurately measure and diagnose fiber optic performance emerged. OTDR technology has continuously evolved and improved, with continuous enhancement of measurement accuracy and functionality.


Purpose of Optical Time Domain Reflectometer

The primary purpose of an OTDR is to characterize the insertion loss of a link by comparing the difference between the amount of backscatter from the near and far ends. It also measures the amount of light reflected for each event (connectors, splices, etc.), not including the backscatter, relative to the launch pulse. It can be used to measure fiber attenuation, joint loss, locate fiber fault points, and understand the loss distribution along the fiber. It is an essential tool in cable construction, maintenance, and monitoring, which can improve the reliability and stability of fiber optic networks.


Principle of Optical Time Domain Reflectometer

The OTDR emits short laser pulses into the optical fiber. These pulses travel along the fiber and encounter various events such as connectors, breaks, and splices, which cause changes in the refractive index and lead to reflections back toward the OTDR. In addition, due to the inherent structure of the fiber and microscopic imperfections within the glass, a small portion of the light pulse scatters in various directions, and this scattered light that travels backward can also be detected by the OTDR. By measuring the returning reflected and scattered light, the OTDR can obtain information about the fiber's characteristics, including attenuation and potential defects.


Features of Optical Time Domain Reflectometer

Fast measurement: It can quickly complete the testing and analysis of optical fibers, saving time and cost. High accuracy: It can accurately measure parameters such as the length, loss, and connection quality of optical fibers, with a resolution that can reach the centimeter or even millimeter level. Non-invasive measurement: It can test optical fibers non-invasively without cutting the fibers, which is convenient and fast and reduces the risk of damage to the fiber optic network. Comprehensive data: It can provide comprehensive information about the fiber, including attenuation, reflectance, and the location of defects.


Types of Optical Time Domain Reflectometer

Full-feature OTDR: Traditional optical time-domain reflectometers that are feature-rich and usually larger, heavier, and less portable than handheld OTDRs or fiber break locators. They often have a main frame that can be fitted with multifunction plug-in units to perform many fiber measurement tasks and have larger color displays. They usually have a greater measurement range and are often used in laboratories and the field for difficult fiber measurements. Hand-held OTDR and fiber break locator: Designed to troubleshoot fiber networks in a field environment, often using battery power. Hand-held OTDRs are easy-to-use, lightweight, and sophisticated, collecting field data and performing rudimentary data analysis. Fiber break locators are low-cost instruments specifically designed to determine the location of catastrophic fiber events. RTU in RF TSS: The testing module of the RF TSS, which enables fibers to be automatically tested from a central location. A central computer controls the operation of OTDR-like test components located at key points in the fiber network.


Precautions for using Optical Time Domain Reflectometer

Proper connection: Ensure that the fiber is properly connected to the OTDR to avoid incorrect measurements due to poor connections. Wavelength selection: Select the appropriate wavelength according to the characteristics of the fiber to ensure the accuracy of the measurement. Calibration: Regularly calibrate the OTDR to ensure its accuracy and reliability. Environmental conditions: Avoid using the OTDR in harsh environmental conditions such as high temperature, high humidity, or strong electromagnetic interference.


Things to consider when purchasing Optical Time Domain Reflectometer[!--empirenews.page--]

Measurement range: Choose an OTDR with a measurement range that meets your needs. Resolution: The higher the resolution, the better the ability to detect small defects. Dead zone: Look for an OTDR with a small dead zone to accurately measure events close to the launch point. Functionality: Consider the features and functions you need, such as the ability to test different types of fibers or perform data analysis. Ease of use: Choose an OTDR with an intuitive user interface and easy operation.


Terms of Optical Time Domain Reflectometer

Accuracy: Defined as the correctness of the measurement, i.e., the difference between the measured value and the true value of the event being measured. Measurement range: The maximum attenuation that can be placed between the instrument and the event being measured, for which the instrument will still be able to measure the event within acceptable accuracy limits. Instrument resolution: A measure of how close two events can be spaced and still be recognized as two separate events. The shorter the pulse duration and the shorter the data sampling interval, the better the instrument resolution, but the shorter the measurement range. Reflectance: The amount of light reflected for each event (connectors, splices, etc.), not including the backscatter, relative to the launch pulse, expressed in decibels (dB) as a negative value. Return loss: Compares the input power to the reflected power and is always a positive number.