Fibre Optic Cable Testing

We are able to carry out fibre optic fault finding and fibre optic testing using an OTDR and visible light source on OS1 9/125, OM1 62.5/125, OM2 50/125 & OM3 50/125 fibre cables.

After the cables are installed and terminated testing can commence. Every Fibre optic cable will need to be tested for continuity, end-to-end loss and then fault found if there are any problems.

If it's a long external fibre optic cable with intermediate splices, you will probably want to verify the individual splices with an OTDR also, since that's the only way to make sure that each one is good. If the cabling is for a fibre optic network we will also be testing power, as power is the measurement that tells you whether the system is operating properly.

Our engineers are fully equipped with mobile test facilities to allow cables to be spliced and tested within vehicles, plant areas or buildings. A full range of fibre optic launch leads allows us to test all types of lengths and cables and produce full test results to show cable performance. We have experience of providing these services for the MOD, BT and petrochemical projects with nationwide coverage.


  • Testing of OM1, OM2 and OM3 to 850nm and 1300nm wavelengths
  • Testing of OS1 to 1310nm and 1550nm wavelengths


Visual Tracing LS
Continuity checking makes certain the fibres are not broken and to trace a path of a Fibre from one end to another through many connections with the use of a visible light source. This allows us to carry out a first line check to identify a faulty or a functional fibre very quickly.

OTDR Testing
Unlike light sources and power meters which measure the loss of the Fibre optic cable plant directly, the OTDR works indirectly. The source and meter duplicate the transmitter and receiver of the Fibre optic transmission link, so the measurement correlates well with actual system loss.

The OTDR, however, uses backscattered light of the Fibre to imply loss. The OTDR works like RADAR, sending a high power laser light pulse down the Fibre and looking for return signals from backscattered light in the Fibre itself or reflected light from connector or splice interfaces.

At any point in time, the light the OTDR sees is the light scattered from the pulse passing through a region of the Fibre. Only a small amount of light is scattered back toward the OTDR, but with sensitive receivers and signal averaging, it is possible to make measurements over relatively long distances. Since it is possible to calibrate the speed of the pulse as it passes down the Fibre, the OTDR can measure time, calculate the pulse position in the Fibre and correlate what it sees in backscattered light with an actual location in the Fibre. Thus it can create a display of the amount of backscattered light at any point in the Fibre.

Since the pulse is attenuated in the Fibre as it passes along the Fibre and suffers loss in connectors and splices, the amount of power in the test pulse decreases as it passes along the Fibre in the cable plant under test. Thus the portion of the light being backscattered will be reduced accordingly, producing a picture of the actual loss occurring in the Fibre. The OTDR presents this information onto the display allowing the engineer to detect problems in the cable caused during installation. If a Fibre is broken, it will show up as the end of the Fibre much shorter than the cable or a high loss splice at the wrong place. If excessive stress is placed on the cable due to kinking or too tight a bend radius, it will look like a splice at the wrong location.

All of our installations are completely tested and quality assured and supplied with hard and soft copy test results.