What type of connector and cable to choose for industrial and military solutions
Designers responsible for the construction of fiber optic bundles for solutions industrial or military must answer the question of what type of connector and cable
to choose. A lot of possibilities arise when it comes to the selection of connectors and cables.
In general, fiber optic connectors, we can group them as follows:
– ferule connectors meeting the standard of MIL-DTL-38999, mainly series III
– ferrule connectors in meeting the standard of the standard MIL-PRF-83526/16 & /17
– lenticular connectors meeting the standard of MIL-DTL-83526/20/21 standard
– lenticular connectors outside the standard of MIL-DTL-83526/20/21
Manufacturers of this type of connectors are many, while they are characterized by several common features characteristics.
Connectors based on the MIL-DTL-38999 standard are characterized by low insertion loss (IL), at 0.3 dB, a high temperature operating range, as from – 65 to
+200 °C, but a relatively low number of permissible connection and disconnection cycles, as about 300 times.
They are also characterized by high sensitivity to dirt due to the fact that they have to direct contact between ferrules during operation.
Their undoubted advantage is the single standard of configuration defined by the aforementioned standard, which excludes the possibility of confusion in the event of the need to connect by fiber optic cable devices from different manufacturers. The second, very important advantage is the ability to of assembling them from components from different manufacturers.
Connectors based on the MIL-DTL-38999 standard should be used where there is no need for frequent connection and disconnection of peripheral devices and a relatively low attenuation.
The FOCA line
The Foca line of connectors based on the MIL-PRF-83526/16 i/17 standard is designed for applications in harsh environments. Again, there are several manufacturers of this type of connector. The main advantages of such a solution are:
– a hermaphroditic system that allows the connection of multiple sets of cables (which is not the case with the MIL-DTL-38999 connectors,
– adaptation to a wide range of cable constructions and diameters by means of molded shoes and wire mesh cable holders. Cable outer diameter, 4 kan. up to 0.61″ (15.5 mm) /. 12 kan. up to 1″ (25 mm)
– Compatibility with other FOCA type connectors
– sealing up to IP 68.
Lens connectors based on the MIL-DTL-83526/20/21 standard are characterized by relatively high insertion loss of up to 2 dB (for single-mode fibers), a lower temperature operating range, as from – 45 to +85 °C, but with a high number of connection and disconnection cycles. connections and disconnections, as about 3,000 times. They are characterized by low sensitivity to dirt, due to the due to the fact that the lenses responsible for the expansion of the light beam are not in contact with each other each other. Of course, the above parameters may vary from manufacturer to manufacturer connectors.
Lens connectors based on the MIL-DTL-83526/20/21 standard can be used where frequent number of connections and disconnections is required, especially in field conditions, where they can become easily soiled.
Choosing fiber optic cables
The second equally very important aspect in the construction of bundles is the selection of cable fiber optic cable.
Fiber optic cables used in the marine industry, that is, installed on vessels must meet requirements that general purpose cables do not.
One such requirement is that the cable manufacturer obtains certification from a classification body classification body, which is recognized in the shipbuilding industry.
Some of the important standards used by classification bodies in approving cables for installation on vessels are:
– IEC 60754-2, which specifies how to test for the potential corrosiveness of gases produced during
their combustion. For vessels, the permissible amount of halides emitted during combustion, which must be at zero. the pH of the solution of exhaust water is defined at a level lower than 4.3 and its conductivity lower than 10μS/mm,
– IEC 61034-1/2: defines the level of opacity that is produced during cable combustion, which for vessels is set at a level of light transmittance greater than 60%.
The aforementioned standards are just one of the elements defined in the so-called Class Programe class units, which defines the procedural and technical requirements for the fiber optic cables used fiber optic cables.
As for cables that can be used directly in the field, one of the very structurally interesting cables intended for use in harsh environments are cables with
loose tube made of stainless steel for eight optical fibers. This is a unique construction in this cable segment, which brings many advantages such as (data for an eight-fiber cable eight-fiber):
– small diameter – 4.5 mm, the cable takes up little space on the reel,
– high instantaneous tensile strength – 4000 N, which allows the cable to be used in difficult working conditions,
– relatively low weight – 39 kg/km which means that the cable is easy to handle in the field.
