Interpretation of The Standard ISO/IEC 14763-3:2024 from the Perspective of Tests & Inspection of Optical Fiber Cabling(Ⅱ)

In the previous article, we introduced that the inspection test of the optical fiber cabling can refer to the international standard ISO/IEC 14763 - 3 which has now been updated to the 2024 version. We simply introduce the following content in the latest ISO/IEC 14763 - 3:2024: deleting the content of plastic optical fiber cabling, adding the content of test of the MPO cabling system, adding the content of the test of E2 link and MPTL by the test method of light source and power meter, adding the descriptions of measurement uncertainties for all the test methods, and introducing the requirements of test limit for attenuation of connectors.

Now let’s take a look at the remaining four updated aspects:

01 Introducing the Dexcription of Reference Connector

Compared with ISO/IEC 14763-3:2014+A1:2018, ISO/IEC 14763-3:2024 introduced the descriptions of reference connector.

According to the clause 5.6.1 “Hardware connector at test interfaces” in ISO/IEC 14763-3:2024, the definition of reference connector is “the connecting hardware to be connected to the cabling under test (i.e. launch test cords and tail test cords) together with the hardware that terminates the substitution test cords and any connecting hardware adaptors are specified as part of the test methods specified by this document and are called reference connectors.”

Reference connectors are used to reduce the measurement uncertainty for the attenuation measurements and are used for multimode and single-mode in single fibre (i.e. LC connector) and multi-fibre connectors (e.g. MPO connectors).

The multi-mode LC and MPO reference connectors are terminated on 50μm fibre and are in accordance with IEC 63267-2-1 for LC and other single fibre connectors. IEC 63267-2-2 specifies requirements for MPO connectors. And multi-mode single-core fiber’s reference connector shall conform to IEC 61755-2-4(PC) &IEC 61755-2-5(APC). The standard detailedly define the dimension and its tolerance parameters of optic fiber core, optical fiber ferrule’s outer diameter and its tolerance parameters, as well as eccentricity error of centre of ferrule and centre of fibre, etc. All these factors are the main factors that caused measurement uncertainties.

Zhaolong’s Multi-fibre Push On (based on rectangular ferrule) 

02  The Single-mode Fiber’s Test Length Changed from "≤2km" to "2km - 10km"

For the part of “measurement uncertainties” in clause 6.9 “inspection of installed cabling” in ISO/IEC 14763 - 3:2024, we can find that there is differences in the test length of single-mode fiber. And the following is the transliteration of the content in the standard:

According to the related requirements in IEC TR 61282 - 14 & ISO/IEC 14763 - 3:2024,

for the measurement uncertainties at 95% confidence level, the single-mode fiber’s test length varies from “≤2km” to “from 2km to 10km” . Take the building cabling as an example, recently the single-mode fiber’s application takes the 10GBASE-LR scheme as the most popular technical scheme with its supporting working distance 10km; the default cabling distance set in ISO/IEC 11801-1：2017 is “ ≤2km”. This update is the amendment for practical applications.

Zhaolong’s Single-mode Optical Fiber Patch Cord

03 Introducing the Content of Normative Inspection of Degree of Cleanliness

Compared with ISO/IEC 14763-3:2014+A1:2018, ISO/IEC 14763-3:2024 added the content of Annex D--optional inspection of polished end face of test connectors.

The degree of cleanliness for the end face of test connectors of optical fiber will directly affect the construction and the judgement of the test results of optical fiber in practical construction and application. Thus, based on the practical applications and needs, ISO/IEC 14763 - 3:2024 put forward the requirements for the degree of cleanliness for the end face of connectors of optical fiber so that the users can operate properly in the acceptance reference or practical measurement,ensuring the quality of the end face of connectors of optical fiber and reducing the test uncertainties of optical fiber.

The Annex D in ISO/IEC 14763 - 3:2024 defines the optional inspection for end face of connector plugs of optical fibers. According to the stipulation in Annex D, in principle, for the users’ quality inspection for the end face of test connector of optical fibers, the reference connectors(single-mode PC, single-mode APC & multi-mode) of different RL (return loss) grades, including the requirements for the end face of fiber core zone and cladding zone, the users can still refer to IEC 61300-3-35. At the same time, according to the attachment, there is some uncertainty in the end inspection. Due to system-to-system variability and differences in the microscope itself, according to IEC 61300-3-35 and ISO/IEC 14763-3, all current microscope systems are unable to achieve 100% matching of test results from multiple microscopes, even different microscopes of the same brand and type. And the test results are also subject to errors.

Table 1--Cladding Zone Requirements of Reference Connectors Source: Annex D in ISO/IEC 14763-3:2024

Table 2--Core Zone Requirements of Reference Connectors Source: Annex D in ISO/IEC 14763-3:2024

04 Introducing the Recommended Cleaning Methods

Compared with ISO/IEC 14763-3:2014 + A1:2018, ISO/IEC 14763-3:2017 adds the content of Annex E, namely the cleaning of connectors.

Annex E specifies two cleaning methods for conventional connectors, that is, cleaning the connector directly and cleaning the connector from the adapter. Detailed speaking, Annex E respectively introduces the cleaning methods and cleaning steps of LC multi-mode cabling interface, LC single-mode cabling interface, LC/APC single-mode cabling interface and single-mode MPO APC cabling interface.

Zhaolong is very concerned about cleaning solutions for light products. For links and channels, the cleaning of the end face of optical fiber is crucially important. Before the product leaves the factory, Zhaolong Interconnect will carry out the 100% detection of the fiber connector end face to ensure the quality and performance of the optical product. Through strict testing and standardized cleaning operations, Zhaolong Interconnect is committed to providing our clients with high-quality, stable performance optical products, reducing the impact of problems such as the end face of optical fiber connectors on the performance of optical products.

Zhaolong’s MPO-LC fan-shaped optical fiber patch cord

Zhaolong single-mode fiber cabling system adopts high-precision ceramic core, advanced grinding technology and equipment. The technical parameters of vertex deviation, fiber height and curvature radius of Zhaolong single-core fiber connector meet GR-326-CORE and IEC 61755 standards. Zhaolong’s multi-core fiber connector adopts high-precision MPO/MTP connectors. It conforms to and is better than GR-1435-CORE and IEC 61754-7, with excellent repeating jointly connection and high reliability. Zhaolong’s products undergo 100% optical performance test, with low loss, high return loss, high reliability. With well-chosen bending insensitive type of single-mode fiber, multi-core optical connector is suitable for dense cabling scenarios, reducing the difficulty of operation and maintenance. At the same time, what we use in optical fibers are high-quality environment-friendly materials which is in line with RoHS and REACH requirements.

Zhaolong multi-mode fiber cabling system provides a comprehensive cabling solution, including cabling products to meet welding needs, high density and ultra-high density pre-terminated fiber cabling products. With advantages in time and costs, excellent modular design, with plug and play, it saves installation time, reduce management and maintenance costs, but also support customization of various lengths, polarity, number of cores. Its component performance is excellent, and the selected high performance and high reliability connectors meet and exceed related international standards. Zhaolong’s connector products will undergo 100% optical testing before leaving the factory, with 3D guarantee, low loss, excellent system performance, fiber performance meets and exceeds IEC 60793-2-10 standards, system performance meets and exceeds ISO/IEC 11801-1 standards.

In summary, the continuous update and improvement of the ISO/IEC 14763-3:2017 standard provides a stricter and more accurate specification for the test of optical fiber cabling systems. On the basis of following this standard, Zhaolong’s optical fiber cabling products have shown excellent performance and advantages, providing a reliable guarantee for the communication needs of various industries. With the continuous progress of technology, it is believed that the future field of optical fiber cabling will usher in more innovation and development, bringing more efficient and stable communication experiences to people's life and work.