Method of collection: Transmission network length can be compiled from three sources: 1) some operators indicate the length of individual routes in network maps or diagrams, which can be entered into a database and added together to produce a total, 2) some operators report the. Method of collection: Transmission network length can be compiled from three sources: 1) some operators indicate the length of individual routes in network maps or diagrams, which can be entered into a database and added together to produce a total, 2) some operators report the. The OZ Optics Benchtop Optical Fiber Length Meter (OFLM) delivers fast, accurate and reliable measurements of optic fiber lengths. This tool saves time and money while preventing measurement errors and improving quality control. The round trip time that the light takes to travel through both fibers is converted to length in kilometers, then divided by two. Fiber optic cable transmission distance is determined by two primary physical factors that affect signal quality as light travels through the fiber medium. Several methods exist, ranging from simple approximations to highly accurate techniques used in manufacturing and installation. Visual Optical Length Tester (VOLT): This device employs a "round-robin" method. Two. Per current standards and specs, maximum supportable distances and attenuation for optical fiber applications by fiber type. Not included are many proprietary designs.