What is the typical coating diameter for a fiber used in tight-buffered cables?

The typical coating diameter for fibers used in tight-buffered cables is indeed 900 microns. This measurement refers to the outer diameter of the buffer coating that surrounds the glass core and cladding of the fiber. The 900-micron coating provides a protective layer that allows for better handling and flexibility of the fiber in applications where it may be pulled or moved around.

Tight-buffered cables utilize this larger coating diameter to facilitate installation and termination processes, making them suitable for indoor environments. The size also provides sufficient mechanical strength to protect the delicate core of the fiber from physical damage during installation and use.

This contrasts with the other options, which represent sizes that do not correspond to typical fiber coatings. For instance, 250 microns refers to the diameter of the bare fiber itself, while 3 millimeters and 0.75 inches are significantly larger than the coatings used on tight-buffered fibers and would not be practical for their intended applications.