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 animportant parameter for minimizing the splice loss of optical fibres when using passivealignment 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 theamount of deflection that occurs as an unsupported fibre end is rotated about the fib