How to determine the attenuation level of pigtail fiber

The most accurate way of measuring the fiber attenuation coefficient requires transmitting light of a known wavelength through the fiber and measuring the changes over distance. The core diameter, cladding diameter and concentricity are the most important factors on how well one can connect or splice two fibers. Three methods exist for measuring it: cutback (the reference standard), insertion loss (the field standard), and OTDR (the diagnostic tool). All calculations use base-10 logarithms. Used only in measured attenuation mode. You can apply this methodology to all types of optical fibers in order to estimate the maximum distance that optical systems use. [pdf]