In fiber optic conduit installation, the term 'fill ratio' refers to the relationship between which two cross-sectional areas?

In fiber optic conduit installation, the term 'fill ratio' refers to the relationship between which two cross-sectional areas?

• A. Cable cross-section and conduit cross-section
• B. Cable outer diameter and conduit inner diameter
• C. Number of fibers and conduit volume
• D. Cable jacket thickness and conduit wall thickness

Answer: (A)

Fill ratio is about how much space inside the conduit is occupied by the cables. It compares the total cross-sectional area of all cables inside the conduit to the cross-sectional area of the conduit bore. In other words, you take the sum of the cable cross-sectional areas and divide by the conduit’s inner cross-sectional area, often expressing the result as a percentage. This ratio helps ensure there’s enough room for pulling, bending, and heat to dissipate, so you don’t crowd the conduit. The other options don’t fit because they mix dimensions that aren’t about occupied space inside the conduit: diameters instead of areas, a count of fibers, or thicknesses of jackets and walls.

Fill ratio is about how much space inside the conduit is occupied by the cables. It compares the total cross-sectional area of all cables inside the conduit to the cross-sectional area of the conduit bore. In other words, you take the sum of the cable cross-sectional areas and divide by the conduit’s inner cross-sectional area, often expressing the result as a percentage. This ratio helps ensure there’s enough room for pulling, bending, and heat to dissipate, so you don’t crowd the conduit.

The other options don’t fit because they mix dimensions that aren’t about occupied space inside the conduit: diameters instead of areas, a count of fibers, or thicknesses of jackets and walls.