DANSK - Dansk Standard

Optical fibres - Part 1-34: Measurement methods and test procedures - Fibre curl
 N DS/EN 60793-1-34

Annotation

This part of IEC 60793 establishes uniform requirements for the mechanical characteristic:

fibre curl or latent curvature, in uncoated optical fibres. Fibre curl has been identified as an

important parameter for minimizing the splice loss of optical fibres when using passive

alignment fusion splicers or active alignment mass fusion splicers.

Two methods are recognized for the measurement of fibre curl, in uncoated optical fibres:

- method A: side view microscopy;

- method B: laser beam scattering.

Both methods measure the radius of curvature of an uncoated fibre by determining the

amount of deflection that occurs as an unsupported fibre end is rotated about the fibre's axis.

Method A uses visual or digital video methods to determine the deflection of the fibre while

method B uses a line sensor to measure the maximum deflection of one laser beam relative to

a reference laser beam.

By measuring the deflection behaviour of the fibre as it is rotated about its axis and

understanding the geometry of the measuring device, the fibre's radius of curvature can be

calculated from simple circular models, the derivation of which are given in Annex C.