ExLRT awarded global Intrinsic Safety certification

Intrinsic safety certification

The ExLRT loop resistance tester has been awarded ATEX and IECEx Intrinsic Safety certification.  UL certification is due to follow within weeks, making ExLRT the most MRO-appropriate loop testing tool available on the global market.


Alan Wilson, Engineering Director at MK Test Systems, said: “The Intrinsically Safe certification of the ExLRT is the latest stage in what has been an extensive and close collaboration with Boeing to create a world-class tool.  The key requirement was an Intrinsically Safe design – once this was achieved, we knew the product would be well-received.”


The ExLRT is classified for Zone 0 use, meaning it can be used on fuelled aircraft. MRO operators can now carry out loop resistance testing using a significantly lighter, more advanced tool than the current industry standard LRT loop resistance tester.


Carl Bullock, MK Test Systems MD, explained “We developed the ExLRT as a much-needed replacement for the existing LRT.  It eradicates the problems commonly associated with the current tool which are that it’s heavy, it uses ageing technology and has obsolescence issues.  I’m incredibly proud of the team for their efforts in developing such a fantastic new product.”

‘Best-in-class’ testing tool being added to Boeing AMMs

A detailed document update programme is underway by Boeing to ensure operators are aware of the newly approval tool by specifying it in the next release of AMM (aircraft maintenance manual).


In the meantime, Boeing has released a Multi Operator Message (MOM) confirming the ExLRT is an approved alternative to the LRT. The MOM also advises that Boeing will grant a No-Technical Objection (NTO) prior to the AMMs being updated in 2020.  NTOs authorise the immediate use of ExLRT.


The ExLRT is now commercially available; the first units will be delivered to Boeing within the month.


The addition of this latest model means that MK now offer a complete family of bond, loop and joint resistance testers. A wide range of specifications and capabilities offer choice for both MRO and OEM environments.

Want to learn more about ELRT’s intrinsic safety certification?

To see the certificates or learn more about ExLRT, visit the product page.  A detailed article about Intrinsic safety certification for bond and loop resistance testers is available here.

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