What maximum splice loss can I require in a tender spec, and how do I verify it at handover?

A well-made fusion splice loses 0.02-0.05 dB. A sound threshold to write into the specification is a bidirectional average ≤ 0.1 dB per splice, with no splice above 0.15 dB. Verification is by OTDR measurement in both directions, at 1310 and 1550 nm to ITU-T G.650.3, with the native traces attached to the report.

Can I allow mechanical splices on a backbone, or must they all be fusion splices?

A mechanical splice typically loses 0.1-0.3 dB and reflects between −35 and −45 dB, while a fusion splice is normally non-reflective, below −60 dB. On a backbone that has to be certified and maintained for years, mechanical splicing becomes the bottleneck of the optical budget. It stays suitable for temporary restorations, with a scheduled and declared replacement.

Can splicing be done in the field with the plant in production?

Yes, working on one leg at a time in agreed windows, nights included, with the other path in service. Every window is approved by the site manager before a closure is opened. Each splice is checked bidirectionally as soon as it is closed, not at the end of the job.

A backbone has been cut overnight: who intervenes and re-certifies the link before service is restored?

We are on call 24/7. The break point is located with the OTDR before any digging, the permanent splice is made by fusion, and the link is re-certified before service is restored. A mechanical restoration is accepted only as a temporary measure, with the replacement already scheduled.

Who splices on behalf of a system integrator without compromising the quality of the individual splice?

The crews are our own and splicing is never subcontracted. Thresholds are fixed in writing before we start and every splice is measured as soon as it is closed. The splice register and the native traces stay with the client, on-premise or on a dedicated cloud in Italy.

Services · Optical-fibre splicing

Every splice measured, not declared.

Fusion and mechanical splicing on FTTH sites, on backbones, in data rooms and in plants that stay running. A 0.05 dB target per fusion splice, verified by bidirectional measurement before the closure is sealed.

Fusion splicer for optical fibre on a workbench, with fibres being prepared

In the spec it is one line. At testing it is a return visit.

Many specifications settle the splicing question with “workmanlike execution”. Then testing arrives. A well-made fusion splice loses 0.02-0.05 dB and is normally non-reflective, below −60 dB. A mechanical splice typically loses 0.1-0.3 dB, reflects between −35 and −45 dB and depends on a gel that over the years gets contaminated, dries out and suffers thermal cycling — in a manhole or an outdoor cabinet more than anywhere else. They are two different techniques, not two variants of the same one.

The difference lands on the link’s optical budget, that is on the margin left in five years’ time, and it surfaces late: once the crew has left and the cable is buried. An out-of-tolerance splice found at testing means a second trip, a closure to reopen and a link to re-certify. That is why our crews measure as they work, not at the end of the job: what we hand over has already been tested. The crews are our own and splicing is never subcontracted.

Services

How the work runs, splice by splice.

Site survey and written thresholds.

Environment, access, working windows and the values to meet: a 0.05 dB target per fusion splice, bidirectional average ≤ 0.1 dB, no splice above 0.15 dB. Survey and quote are free of charge: we work from Modena and Emilia-Romagna, project by project nationwide.

Splicing in the field, plant running.

Controlled cleaving and cleaning, a calibrated splicer, closures and cabinets sealed as designed. We work in agreed windows, nights included, without stopping production or service.

Measured as it is made, not at the end.

Every splice is checked bidirectionally as soon as it is closed: if it is out of threshold it is redone on the spot. Mechanical splicing remains acceptable only for temporary restorations, with a scheduled, declared replacement.

Register, handover, perimeter.

Every splice enters the link register and is matched against the native measurement traces. Reports, traces and as-built records stay yours: on-premise in your own environment or on a dedicated cloud in Italy, in directly staffed data centres.

An example, step by step.

Illustrative case, not a real client. An engineering company with three buildings linked by a fibre ring: 2.4 km of route, 38 splices between manhole closures and panel terminations, and a specification that devotes a single line to splicing. The environment does not help — oils, dust, wash-downs, vibration — and production does not stop: work runs on one leg of the ring at a time, with the other in service.

The number first, then the cable

At the survey the thresholds are fixed: a 0.05 dB target per fusion splice, bidirectional average ≤ 0.1 dB, no splice above 0.15 dB. It is also settled where mechanical splicing is allowed: temporary restorations only, with a scheduled replacement.
One leg at a time

The crew splices the first leg in agreed windows while the second stays in service. The plant manager approves each window before a closure is opened.
Measured as soon as it is closed

Every splice is checked bidirectionally on the spot. In this example two splices come out at 0.18 and 0.22 dB: they are redone the same day, not discovered at testing three weeks later.
The bend weighs as much as the splice

In tight panels the crew uses the fibre subcategory suited to the real radius — G.657.A2 or B3 — because a patch cord bent to 7.5 mm can lose as much as a poor splice, and on an OTDR trace the two look alike.
Handed over already tested

The ring closes with native traces, one report per fibre and a splice register aligned with the as-built records. The documentation is delivered with the work, not weeks afterwards.

In this example the 38 splices stay around a 0.05-0.06 dB link average and the two out-of-threshold splices cost half a crew day: the estimate, on this typical case, is 2-3 person-days saved against a return to site with a closure to reopen and a link to re-certify. Measurements, native traces and as-built records stay inside the client’s perimeter — on-premise or on a dedicated cloud in Italy — and no network data leaves it.

An illustrative example on a typical case: the assumptions are recalibrated on your own data.

What you are left with.

Fusion splices with a 0.05 dB loss target, verified by bidirectional measurement rather than estimated by eye.
Thresholds written before we start: link average ≤ 0.1 dB, no splice above 0.15 dB, non-reflective splices.
Links handed over already certified, with the native traces alongside the report: no return visits for splices found at testing.
A splice register consistent with the as-built records and with the real position of closures, cabinets and terminations.
On call 24/7 for restorations: the damage located by OTDR before any digging, the link re-certified before service is restored.

Who has this problem.

Operators and network contractors that must close hundreds of splices per cabinet without slowing the installation.
System integrators that outsource splicing alone and do not want to lose quality on the individual splice.
Plants, hospitals and data rooms where splicing happens with the installation live, in agreed windows including nights.
Anyone with a backbone cut overnight who must restore service with the link re-certified, not merely repaired.

Two ways of working.

By project, from survey to handover

Survey and quote free of charge, execution by our own crews with no subcontracting, testing and documentation delivered together with the work. From Modena and Emilia-Romagna, project by project nationwide.

On call 24/7 for faults and restorations

The damage located by OTDR before any digging, splicing in the field in agreed windows including nights, the link re-certified before service is restored.

In both cases measurements, native traces and as-built records stay yours: on-premise in your own environment or on a dedicated cloud in Italy, in directly staffed data centres.

Frequently asked questions

The questions we are asked most often.

What maximum splice loss can I require in a tender spec, and how do I verify it at handover?

A well-made fusion splice loses 0.02-0.05 dB. A sound threshold to write into the specification is a bidirectional average ≤ 0.1 dB per splice, with no splice above 0.15 dB. Verification is by OTDR measurement in both directions, at 1310 and 1550 nm to ITU-T G.650.3, with the native traces attached to the report.
Can I allow mechanical splices on a backbone, or must they all be fusion splices?

A mechanical splice typically loses 0.1-0.3 dB and reflects between −35 and −45 dB, while a fusion splice is normally non-reflective, below −60 dB. On a backbone that has to be certified and maintained for years, mechanical splicing becomes the bottleneck of the optical budget. It stays suitable for temporary restorations, with a scheduled and declared replacement.
Can splicing be done in the field with the plant in production?

Yes, working on one leg at a time in agreed windows, nights included, with the other path in service. Every window is approved by the site manager before a closure is opened. Each splice is checked bidirectionally as soon as it is closed, not at the end of the job.
A backbone has been cut overnight: who intervenes and re-certifies the link before service is restored?

We are on call 24/7. The break point is located with the OTDR before any digging, the permanent splice is made by fusion, and the link is re-certified before service is restored. A mechanical restoration is accepted only as a temporary measure, with the replacement already scheduled.
Who splices on behalf of a system integrator without compromising the quality of the individual splice?

The crews are our own and splicing is never subcontracted. Thresholds are fixed in writing before we start and every splice is measured as soon as it is closed. The splice register and the native traces stay with the client, on-premise or on a dedicated cloud in Italy.

Worth reading before you decide.

Other services

OTDR certification and testing ODN/PON design and optical budget As-built documentation, labelling and network records Support on tender specifications and compliance

The first step

A site survey. Then the numbers.

Tell us the environment and the need; we tell you times, methods and costs. Before we start, not after.

30 minutes video call or site survey ~~€150~~ free

Request an intervention

We reply within one business day. Survey and quote are free.