Testing OM5/OM4 fiber with OM3 Test Reference Cords

The Fluke Networks Test Reference Cords (TRCs) are made with OM3 fiber with a core concentricity of +/- 0,7 µm. Normal multimode fiber has a core concentricity of +/ 2,0 µm. The tighter core concentricity is required to maintain Encircled Flux compliance at the end of the TRC. You can test OM2, OM3, OM4 and OM5 with these TRCs, since we are measuring optical loss, not modal bandwidth which is limited to testing in the laboratory.