Electical Contractor

Elevator connection requirements  

Immunity to EMI makes copper-fiber cable attractive We marveled at photos of the Titanic taken by the team headed by Dr. Robert Ballard, who located the shipwreck in 1986. But how many of us realized the photos were made possible by a special type of fiber optic cable?

The majority of Fiber optic connectors are still installed in a process that uses an adhesive to attach the connector to the fiber and polishing to finish the end surface of the connector.

Recently, we received a phone call from a fiber optic instructor we know asking an unusual question. Can you run single-mode fiber to the desktop? Of course, we told him, why not?

The optical time domain reflectometer (OTDR) has been an important tool for fiber optic testing and troubleshooting since its invention 25 years ago. We have discussed this several times in this column and in other Electrical Contractor articles, so I hope you are already familiar with them.

Industry standards make the world go ’round. No kidding. Without standards, communications and networking would never work. Telephones allow you to talk to anyone in the world, assuming you speak their language. Standards are the “language” of networks and communications.

Those involved in fiber optics are incurable optimists. Market forecasts always show upward trends and promise that fiber is going to replace copper wire or rebuff wireless and whatever other alternative methods of communications are currently being hyped.

Many fiber optic specifications and tests refer to wavelength because most parameters have some wavelength dependency. Attenuation, for example, is caused by absorption and scattering. Absorption occurs at certain wavelengths and scattering gets less significant at longer wavelengths.

Some years back, fiber optic connector manufacturers started offering connectors that terminated fiber quickly without using adhesives or requiring polishing. The manufacturer glued a short stub fiber into the connector ferrule and polished it perfectly in the factory.