Professional fibre optic testing and certification
Fibre optic testing and certification provide documented proof that a fibre link performs to specification. Whether you are commissioning a new fibre optic installation, diagnosing a fault, or evidencing compliance for an audit or handover, certified test results are the difference between assuming a network works and proving it does.
As members of the Fibre Optic Industry Association, ACCL’s engineers test with calibrated equipment and issue full certification reports covering insertion loss, reflectance, and length for every link, giving you a complete, auditable record of network performance.
Our fibre optic testing services
We test to recognised standards and report every result. Our testing covers new installations, fault finding, and periodic verification of existing infrastructure.
OTDR testing
Optical Time-Domain Reflectometer testing that maps the entire fibre run, pinpointing splices, connectors, bends, and faults by distance. Carried out bi-directionally and at every relevant wavelength for an accurate, complete trace.
Insertion loss (OLTS) testing
Optical Loss Test Set measurement of end-to-end attenuation against the link loss budget, confirming each link meets its required performance threshold.
Fault diagnosis & location
Rapid identification and precise location of breaks, high-loss joints, and degradation, feeding directly into our fibre optic repair service.
Certification & reporting
Full documented certification per link, ready for warranty, compliance, and project handover. Results delivered in a clear, auditable format.
Pre- and post-installation testing
Verification before, during, and after installation so issues are caught early and the finished network is signed off with confidence.
Annual & periodic verification
Scheduled re-testing of critical links to detect degradation before it causes downtime, with equipment kept on a regular calibration cycle.
Why certified testing matters
Uncertified fibre is a liability. Without documented test results you cannot prove a link meets standard, support a warranty claim, or satisfy an auditor, and intermittent faults can go undetected until they cause an outage. Certified testing gives you measured evidence of performance, a baseline to compare against in future, and the documentation required for compliance. It is the final, essential step that turns a fibre installation into a verified asset.
Trusted on critical infrastructure
Our engineers have delivered fibre testing and certification across demanding commercial and financial environments, including major banking, exchange, and transport infrastructure where accuracy and documentation are non-negotiable. The same rigour applies to every project, from a single link to a full campus, and pairs naturally with our fibre splicing and termination work.
Get in touch today
Have a no-obligation chat with one of our data cabling experts, who can recommend a solution to suit your requirements and budget.
Featured case studies
-
Royal Air Force Museum London
The Royal Air Force (RAF) Museum in Hendon, London, was opened in 1972, to showcase the history of the RAF. The museum was awarded a grant from the Heritage Lottery Fund to support redevelopment to celebrate and commemorate the Centenary…
-
St David’s Shopping Centre – Cardiff
Time and motion – Speed of response proves to be essential in a major project. St David’s, the new home of fashion in Wales, is one of the largest retail centres in the country and represents 39% of the total…
What our clients think
We would like to take this opportunity to thank, You, Wayne and the team for such an excellent and professional implementation.
The organisation was fantastic and the way you worked within the building was great 😊 the business users did not even know what was going on in the building 😊 We would definitely not hesitate to use you guys again.
Wise Music Group
I have been dealing with Wayne at ACCL for some time now, as I was tasked by my employer to refurbish our server cabinets across 30 offices in London. I can’t begin to express how good Wayne and his guys are. They have replaced and refurbished a large number of our server cabinets so far, with no issues, all in a very timely manner.
They have done a highly professional job, have always kept in contact, and have given us advice/suggestions on what was needed when we weren’t too sure. I would highly recommend using ACCL for any IT/Cabling work.
TUI / Werner May

Need your fibre tested and certified?
Whether you are signing off a new installation or diagnosing a fault, our FIA-certified engineers provide accurate testing and full certification. Contact us to arrange an attendance.
Frequently Asked Questions – (FAQs)
What is OTDR testing?
OTDR (Optical Time-Domain Reflectometer) testing sends light along the fibre and measures the reflections to map the whole run, locating splices, connectors, bends, and faults by distance. We test bi-directionally and at every relevant wavelength for an accurate, complete trace.
What is the difference between OTDR and insertion-loss testing?
OTDR maps events along the fibre and locates faults; insertion-loss (OLTS) testing measures total end-to-end attenuation against the link loss budget. A full certification uses both.
Do you provide a certification report?
Yes. We issue documented certification per link covering insertion loss, reflectance, and length, in a clear, auditable format suitable for warranty, compliance, and handover.
Why do I need my fibre certified?
Certification proves each link meets standard, supports warranty and compliance, provides a performance baseline, and catches faults before they cause downtime.
Can you test an existing fibre network?
Yes — we carry out periodic and annual verification of existing links to detect degradation early, as well as testing new installations.
Is your test equipment calibrated?
Yes. Our test equipment is kept on a regular calibration cycle, so results are accurate and defensible.




