200°C SST Fiber Optic Cable - Fiber In Metal Tube (FIMT) - Communication / Sensing Optical Cable

Aliases: FIST (Fiber In Steel Tube) - 200°C Grade, 200°C Seamless SST Encapsulated High-Temp Cable, 200°C Polyimide-Buffered Metal Tube Fiber, 200°C Downhole High-Temp Sensing Cable, 200°C Industrial Kiln/Oven Monitoring Fiber, 200°C DTS-Ready High-Temp SST Fiber, 200°C Hydrogen-Shielded High-Temp Fiber Cable, 200°C Hermetic SST Fiber Optic Unit, 200°C High-Pressure SST Sensing Cable

1. Product Overview of OFSCN® 200°C High-Temperature Fiber Optic Cable

The OFSCN® 200°C High-Temperature Fiber Optic Cable is a sensing-grade cable specifically engineered for extreme industrial environments. It features a single-layer seamless stainless steel tube encapsulation housing OFSCN® 200°C Polyimide (PI) coated fibers. Combining superior hydrogen shielding, high mechanical protection, and sensitive physical signal transmission, this cable serves as the ideal core sensing unit for Distributed Fiber Optic Sensing (DFOS) systems, including DTS, DAS, and DSS.

2. Technical Parameters of OFSCN® 200°C High-Temperature Fiber Optic Cable

Key Parameters	Spec A (2.0mm)	Spec B (3.0mm)	Custom Options
Outer Diameter (OD)	2.0 mm	3.0 mm	1/8" (3.175mm) / 1/16" (1.58mm)
Wall Thickness	0.2 mm	0.3 mm	Customizable
Tube Material	304 SS (Default) / 316L	304 SS (Default) / 316L	304 / 316L / Hastelloy, etc.
Theoretical Weight	~8.96 kg/km	~20.14 kg/km	Varies by OD & Wall thickness
Tensile Strength	> 550 N	> 1200 N	High resistance to tensile creep
Crush Resistance	> 100 MPa	> 100 MPa	Rated for deep-sea/downhole high pressure
Operating Temp.	-60 to +200 °C	-60 to +200 °C	Stable long-term performance
Min. Order Qty (MOQ)	1000 Meters	1000 Meters	-

3. Internal Fiber Configuration of OFSCN® 200°C High-Temperature Fiber Optic Cable

The cable can be flexibly configured with one or more high-quality PI-coated fibers:

• Fiber Types:

Single-mode: OFSCN® 200℃ SM Polyimide Optical Fiber

Multi-mode: OFSCN® 200℃ MM Polyimide Optical Fiber

• Coating Material: High-temperature Polyimide (PI), with a thickness of approximately 15μm.
• Connectivity: Available with factory-prepped FC/APC or FC/PC high-temperature connectors, or compatible with standard fusion splicing.

4. Distributed Fiber Optic Sensing (DFOS) Compatibility of OFSCN® 200°C High-Temperature Fiber Optic Cable

This product is optimized for the following distributed sensing technologies:

4.1 Distributed Temperature Sensing (DTS) — Based on Raman Scattering

This is the most classic and mature application for this cable, typically using multi-mode (MM) fiber.

• Hydrogen Shielding: In high-temperature chemical environments like oil and gas wells, the seamless steel tube acts as the ultimate hydrogen barrier, preventing "hydrogen darkening" and extending system lifespan.
• Fast Thermal Response: The thin-walled (0.2mm–0.3mm) metal tube has minimal thermal resistance, allowing for real-time and sensitive feedback of ambient temperature changes.

4.2 Distributed Temp. & Strain Sensing (DTSS) — Based on Brillouin Scattering

Used for long-distance structural health monitoring or deep-well parameter measurement, typically using single-mode (SM) fiber.

• Decoupled Measurement: Fibers can be placed with "excess length" (loose-tube state) to measure pure temperature, avoiding cross-interference from mechanical strain.
• Strain Monitoring: Through specialized tight-coupling processes, the high modulus of the stainless steel tube allows it to serve as a strain sensing unit for structural deformation monitoring.
• High-Pressure Protection: 100 MPa pressure resistance ensures signal fidelity even under extreme hydrostatic or lateral pressure.

4.3 Distributed Acoustic/Vibration Sensing (DAS/DVS) — Based on Rayleigh Scattering

Uses Phase-sensitive Optical Time Domain Reflectometry (φ-OTDR) to detect vibrations, typically using single-mode (SM) fiber.

• Acoustic Coupling: The high rigidity of the seamless stainless steel tube efficiently transmits external vibrations (such as leaks or seismic activity) to the internal fiber.
• Thin Coating Advantage: The 15μm PI coating is significantly thinner than traditional polymers, greatly reducing acoustic signal absorption and improving sensing fidelity.

5. Sensing Technology Matching Matrix of OFSCN® 200°C High-Temperature Fiber Optic Cable

Sensing Tech	Principle	Recommended Fiber	Key Advantages
DTS	Raman Scattering	Multi-mode (MM)	Hydrogen resistance & fast thermal response; Ideal for power grids and oil wells.
DAS / DVS	Rayleigh Scattering	Single-mode (SM)	High rigidity metal jacket; Superior acoustic conduction for pipeline monitoring.
BOTDA / R	Brillouin Scattering	Single-mode (SM)	High crush resistance; Suitable for deep wells or extreme pressure environments.
F-P / FBG	Wavelength Shift	Single-mode (SM)	PI fiber is ideal for grating writing; metal tube provides mechanical armor.