Outer sheath of multimode fiber optic patch cord

The outer sheath of multimode fiber optic patch cords is typically color-coded and made from protective materials like PVC or LSZH to ensure durability and safety. Color Coding by Fiber TypeMultimode fiber optic patch cords use distinct outer sheath colors to differentiate fiber grades and facilitate identification in network installations: OM1 and OM2: OrangeOM3: Aqua (light blue)OM4: Violet or aqua depending on manufacturer standardsOM5: Lime green These colors help technicians quickly distinguish multimode fibers from single-mode fibers, which usually have a yellow sheath.

Sheath Materials and Properties

The outer sheath serves as the primary protective layer for the fiber, providing resistance against physical damage, moisture, and environmental factors. Common materials include: PVC (Polyvinyl Chloride): Standard indoor use, flexible, cost-effective, but not suitable for plenum spaces due to smoke and toxicity concerns.

LSZ

H (Low Smoke Zero Halogen): Emits minimal smoke and toxic gases when burned, ideal for high-safety areas and European installations.

LSO

H (Low Smoke Zero Halogen, similar to LSZH): Often used in high-quality multimode patch leads for indoor applications.

Additional Considerations

Indoor vs Outdoor: Outdoor multimode patch cords may include armored jackets, waterproofing, or reinforcement (FRP) to withstand environmental stress. Simplex vs Duplex: The sheath may cover a single fiber (simplex) or two fibers (duplex) for bidirectional transmission. Mechanical Protection: The sheath cushions the fiber against bending, abrasion, and tensile stress, ensuring signal integrity in short-distance LAN or data center applications.

In summary, the outer sheath of multimode fiber optic patch cords is both a color-coded identifier and a protective layer, typically made from PVC or LSZH/LSOH materials, designed to safeguard the fiber while supporting indoor or outdoor network installations.