AFL now offers OSP MicroCore® tonable cables. The tonable feature allows network owners that deploy these high-density fiber cables within their underground cabling system the ability to locate them using standard electromagnetic locator devices.

 

What is a tone or locate wire?

In order to locate and mark the cable location along the underground pathway, there must be a continuous metallic (electrically conductive element) material placed within the pathway. This electrically conductive element can be part of the duct system, armor layer within the cable or a tone-wire placed under the cable jacket. 

 

What is tonable OSP MicroCore?

Tonable OSP MicroCore loose tube fiber optic cables (LM, LM200 and LMHD) include a stranded copper conductor that is place longitudinally directly under the jacket. After the cable is jetted into an underground micro-duct or pulled through a traditional HDPE duct pathway, the copper wire is accessed and connected to a signal transmitter and energized. The low-resistance copper wire acts as an antenna that propagates the imposed signal allowing its location to determined using a signal detection device.

 

Why use a tonable OSP MicroCore?

Historically, a tonable option for a traditional loose tube or ribbon fiber optic cable meant the use of an armored OSP cable package. Because armored fiber optic cables are typically larger (and heavier) than OSP MicroCore tonable cables for any fiber-count, the armored option limited the amount of fiber that could be placed in a given pathway size. For example, a 1.25” SDR 11 HDPE duct has an inside diameter (ID) of 1.3”. Using recommended maximum duct fill ratio 70% for single cable installation, the largest armored loose tube or ribbon cable that can be reliably placed in the duct is a 432-fiber. Refer to the table for a comparison to using the OSP MicroCore tonable product.  

The use of an OSP MicroCore tonable cable in place of an armored OSP cable offers network owners the ability to add two to three times the amount of fiber to their cable pathway. Additionally, the reduced diameter and lighter weight construction of OSP MicroCore tonable cable package allows for longer cable lengths on smaller reels which improve job site handling, reduced splice points and lower scrap.