FOC-egelderblomThere are two types of IEC standards for MT/MPO measurements using interferometry.

The first is the “Measurement Standard” and its primary purpose is to try and ensure that different instruments yield the same measurement results.  This standard includes information on measurement techniques, measurement parameters, fitting regions, reference points, calculations and in some cases the algorithms used to define each parameter.  This is a priority standard and its number is 61300-3-30. The link on the IEC webstore is . The reality is that this release is dated 2003 and has very little resemblance to the updated document currently making its way through the standards process - and scheduled for publication in 2016 – see images below.

US Conec is a member of the IEC WG4 along with 6 committees and have actively been working on the updated version of this standard for over a decade.  Parameters do not exist in the current standards but much will change once the new standard is published this year and many new parameters will be implemented in 61300-3-30.  Of course, standards such as 61755-3-31 may lag even further behind 61300-3-30 creating even more confusion.

Below you find some screenshots that share some of the standard work that has been going on.

Navigating IEC standards for MT MPO measurements using interferometry Fiber Optic Center











Navigating IEC standards Performance or Interface Standards Fiber Optic CenterThe second is “Performance or Interface Standards” which relate to specific connector styles or groups. For example, there might be one for MT connectors and another for angled MT connectors. These documents refer to 61300-3-30 as the measurement technique and then continue to elaborate on specific parameters to be measured, ferrule dimensions, tolerances and pass/fail limits. These documents are aimed more towards companies manufacturing, polishing or purchasing connectors.



Although many documents are in development or maintenance, it does not appear that many of them have made it to publication. It is an unfortunate state of affairs that the standards often lag the industry by many years…..

Even though there are many new MT measurement parameters, it is important to note that most are not yet fully implemented for anything beyond single row MT 12 connectors.

Navigating IEC standards Ferrule measurement areas Fiber Optic Center






Navigating IEC standards optical interface endface geometry Fiber Optic Center




Total Coplanarity and Fiber Line were critical building blocks in the process of building the new standard which is scheduled for release this year (2016) and it looks that Coplanarity will be replaced by Minus Coplanarity and Fiber Line will be encompassed in the GL calculation for the new release.

The reason for this parameter “failure” is more related to the interferometer manufacturer using the implementing test parameter ahead of the new standard release.

The current release is from 2003 and lacks behind the industry requirements. Many customers requires a more up-to-date (higher and better specifications), so it’s been implemented in this software of some suppliers. Ultimately it hasn’t been adopted yet and if you don’t see value in it, you may turn these test parameters off and still might the standard.

However, if you want to prepare for the future, please review our MT polishing process ( or feel free to contact us so we can arrange a visit to help evaluate your entire process.

Questions can be asked through  Fiber Optic Center is a resource for questions on this and all technical subjects.  AskFOC can be found at: and the Fiber Optic Center technical experts will answer your questions here.

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Erwin Gelderblom

About Erwin Gelderblom

Erwin Gelderblom, EMEA Business Development, Technical Sales Erwin manages sales and technical support for FOC in the EMEA area. Earlier positions included Toshiba Medical Systems, Framatome, and Amphenol. Erwin joined Molex Fiber Optics in 1997 as European account manager, developing business for optical backplane connectors and optical flex circuit products to become the largest sales area for Molex. Erwin completed a four-year internal MBA program while at Molex, and was responsible for market analyses, growth strategy and business development for Molex Europe. Following ten years at Molex, Erwin worked for Prysmian Cables in the Netherlands. Since 2009, Erwin has worked with FOC, handling consumables, production and inspection equipment. Erwin graduated in 1987 from MBO college in Gouda, Netherlands with a BS degree in electronics engineering and lives in the Rotterdam area with his wife Anita and their three children, Nils, Lianne and Finette. Follow @FiberExprtsFOC