Iven | www.ofscn.org
Last Updated: 13 February 2026
Aliases: Armored Micro SST Fiber Cable, Rodent-Proof Metal Tube Fiber Cable, Hermetic Stainless Steel Fiber Unit, FIST (Fiber In Steel Tube) Cable, Ultra-Slim Seamless SST Sensing Cable, Single-Layer SST Optical Unit, Utility Gallery Specialty Fiber Cable, Subsea-Rated SST Fiber Sensing Cable, Structural Health Monitoring (SHM) Fiber Cable
This is a companion discussion topic for the original entry at https://www.ofscn.org/dofs/85-c-sst-optical-cable.html
The OFSCN® 85°C Seamless Steel Tube Optical Cable (also known as FIMT - Fiber In Metal Tube) is a specialized armored micro-optical cable designed for both communication and distributed fiber optic sensing in demanding environments.
Technical Characteristics
Unlike traditional flame-retardant or plastic-jacketed cables, this product utilizes a seamless stainless steel tube (typically 304 or 316L) as its primary protective layer. This construction provides several critical technical advantages:
- Mechanical Protection: It offers superior crush resistance and is effectively rodent-proof and insect-proof.
- Hermetic Sealing: The seamless metal tube prevents moisture, hydrogen, and corrosive gases from reaching the internal fibers.
- High Temperature Stability: Rated for continuous operation up to 85°C, maintaining structural integrity where standard PVC or LSZH cables might soften.
- Compact Form Factor: Standard diameters are available at 2.0mm or 3.0mm, with customizable options like 1/8 inch or 1/16 inch for tight-space installations.
Fiber Configuration
The cable can be populated with various fiber types depending on your application:
- Single-mode: OFSCN® G.652D or G.657 series.
- Multi-mode: OM2, OM3, or OM4 for high-bandwidth data transmission.
- Hybrid: Combinations of single-mode and multi-mode fibers within a single tube.
Standard Product Visuals
Applications
This cable is widely used as a Distributed Fiber Optic Sensor for:
- Structural Health Monitoring (SHM): Monitoring strain or temperature in bridges, tunnels, and utility galleries.
- Distributed Sensing: Compatible with DTS (Raman), DAS (Rayleigh), and DTSS (Brillouin) technologies.
- Subsea/Harsh Environments: Providing a pressure-resistant housing for fibers in underwater or underground deployments.
For more detailed specifications, you may visit the official product page:
OFSCN® 85°C Seamless Steel Tube Optical Cable