Which statement combines the tight-buffered and loose-buffered coating diameters correctly?

Which statement combines the tight-buffered and loose-buffered coating diameters correctly?

• A. Tight-buffered 900 um; Loose-buffered 250 um
• B. Tight-buffered 250 um; Loose-buffered 900 um
• C. Tight-buffered 900 nm; Loose-buffered 250 um
• D. Tight-buffered 900 um; Loose-buffered 900 um

Answer: (A)

Coating diameters around optical fiber come in two common sizes, reflecting how the fiber is used in different cable constructions. Tight-buffered fibers have a thicker protective layer directly around the glass, typically about 0.9 millimeters in diameter (900 μm). This makes the fiber sturdy and easy to handle in patch cables and connectorized runs. Loose-buffered fibers, on the other hand, use a thinner buffer layer around the glass—about 0.25 millimeters in diameter (250 μm)—because the fiber is meant to sit inside a larger protective tube or jacket, allowing more flexibility and easier packing in loose-tube or outdoor cables. So the pairing tight-buffered 900 μm with loose-buffered 250 μm matches the standard practice, with 0.9 mm for the tight-buffer and 0.25 mm for the loose-buffer. The other options mix units or imply sizes that don’t align with how these coatings are typically specified.

Coating diameters around optical fiber come in two common sizes, reflecting how the fiber is used in different cable constructions. Tight-buffered fibers have a thicker protective layer directly around the glass, typically about 0.9 millimeters in diameter (900 μm). This makes the fiber sturdy and easy to handle in patch cables and connectorized runs. Loose-buffered fibers, on the other hand, use a thinner buffer layer around the glass—about 0.25 millimeters in diameter (250 μm)—because the fiber is meant to sit inside a larger protective tube or jacket, allowing more flexibility and easier packing in loose-tube or outdoor cables.

So the pairing tight-buffered 900 μm with loose-buffered 250 μm matches the standard practice, with 0.9 mm for the tight-buffer and 0.25 mm for the loose-buffer. The other options mix units or imply sizes that don’t align with how these coatings are typically specified.