What is the primary purpose of using a gel or absorbent tape in a loose tube cable?

The primary purpose of using a gel or absorbent tape in a loose tube cable is to prevent water from entering the cable. Loose tube cables are designed to allow the optical fibers to move within the tube, which is beneficial for expanding and contracting with temperature changes. However, this design also poses a risk of moisture ingress if the cable is exposed to external water sources. The gel or absorbent tape acts as a barrier, preventing water from contacting the fibers and potentially causing damage or degradation to the optical signal.

In addition to moisture control, the implementation of gel or absorbent tape can also help maintain the integrity and performance of the cable, ensuring that it functions effectively in various environmental conditions.