This procedure defines a method by which the optical insertion loss of a complete fiber optic interconnection can be measured. There are two procedures that may be used. In the first power is measured through a continuous length of fiber or cable. The fiber/cable is then cut, the interconnection device is installed, and power is remeasured. In the second procedure, power is measured through a pigtailed device. The input/cable is then cut back and the power is remeasured. These procedures do not apply to cable assemblies.