On a 3 km metro tunnel or a 800 m prestressed concrete bridge, the old playbook is familiar and flawed: stick 40 discrete FBG strain tags at bearings and expansion joints, wire 120 electrical strain gauges along the deck, then pray the crack opens where you put the sensor. Electrical gauges drift near traction power, discrete FBGs miss the 200 m of deck between bearings, and both leave blind zones that only show up after spalling. Armored FBG Array Strain Sensing Cable — Thousands Of Weak Fiber Bragg Gratings Densely Inscribed On Single Mode Fiber SMF-28 Packaged In PE PU Teflon Mid Layer And Mechanical Armored Outer Jacket For Distributed Quasi Distributed Strain Sensing Structural Health Monitoring Bridge Tunnel Dam Pipeline Perimeter Intrusion Warning EMI Immune High Sensitivity Custom Spacing FC APC Connector DEAN Technology Beijing Dian Kongshuo Science And Technology Development Co Ltd rewrites that playbook by turning one optical fiber into a continuous strain ruler: thousands of low-reflectivity gratings inscribed at 1 m or 0.5 m pitch along SMF-28, protected by a PE/PU/Teflon inner coat and a mechanical armored sheath, interrogated by a single FBG demodulator at the cable end. But how exactly does weak-grating density beat discrete FBGs on spatial resolution without killing the optical signal budget, why does the armored jacket matter more in a buried pipeline trench than in a lab bench, and what makes a Chinese FBG-array manufacturer like DEAN Technology a rational source for EPC contractors needing custom grating pitch and FC-APC termination rather than an off-the-shelf 8-sensor string? Below is the full breakdown for structural engineers, SHM system integrators, and perimeter-security specifiers evaluating distributed fiber optic strain cabling.
The Armored FBG Array Strain Sensing Cable — Thousands Of Weak Fiber Bragg Gratings Densely Inscribed On Single Mode Fiber SMF-28 Packaged In PE PU Teflon Mid Layer And Mechanical Armored Outer Jacket For Distributed Quasi Distributed Strain Sensing Structural Health Monitoring Bridge Tunnel Dam Pipeline Perimeter Intrusion Warning EMI Immune High Sensitivity Custom Spacing FC APC Connector DEAN Technology Beijing Dian Kongshuo Science And Technology Development Co Ltd is built on two reconciled advances—optical and mechanical:
Ultra-Weak Grating Array = Quasi-Distributed Strain Ruler. Traditional discrete FBG uses 10–40 strong gratings (reflectivity 10–90%) per fiber; you plan each point in advance and blind zones are permanent. Ultra-weak FBG (UWFBG) inscribes thousands of gratings at 0.01–1% reflectivity along one SMF-28, spaced 0.5 m / 1 m / 2 m per design. Each grating reflects a sliver of light; the interrogator separates them by wavelength/time and reconstructs a continuous strain profile. Result: a 2 km cable carries 2000–4000 sensing points with no electrical wiring, no junction boxes, no per-point calibration drift. Micro-strain from early deck bending, tunnel lining creep, or pipeline soil settlement shows as a wavelength shift curve, not a single alarm threshold.
Armored Jacket = Field Survival, Not Just Packaging. The inner coating (PE, PU, or Teflon, ≤1.5 mm OD) decouples the fiber from radial crush; the outer mechanical armor (steel strand, stainless braid, or double-layer stranded structure per DEAN's buried-series cousins) takes tensile load during pull-through, impact from gravel, and long-term moisture. Without armor, a bare acrylate-coated fiber survives the lab but fragments in a pipe trench after one backfill roller pass. With armor, the cable is pulled through conduit like a conventional instrument cable, survives −30–80℃ cycles, and keeps grating pitch stable for 10+ year monitoring horizons.
From the product node Armored FBG Array Strain Sensing Cable (en.dsc.net.cn/item/671.html) and sibling pages:
Core principle: Thousands of weak gratings densely processed on optical fibers, packaged into cables for strain sensors in fiber grating array sensing systems.
Fiber base: Single-mode SMF-28, C-band inscription (typical 1460–1610 nm working range, ±0.5 nm tolerance).
Grating geometry: 5–10 mm grating length, reflectivity configurable (weak-array class), FWHM 0.2–0.3 nm, SLSR ≥15 dB.
Cable structure: Inner coating PE / PU / Polytef (Teflon) ≤1.5 mm; outer armored jacket 3 / 4 / 5 mm OD options; pull strength >100 kpsi class.
Termination: FC/APC standard (FC/UPC optional), custom length, custom grating spacing.
Immune properties: EMI immune, intrinsically safe in high-voltage/substation/rail traction environments.
Typical roles: Strain monitoring primary; temperature-capable when paired with temperature-compensated array design; perimeter intrusion warning when laid along fence line.
Manufacturer: DEAN Technology / Beijing Dian Kongshuo Science and Technology Development Co., Ltd. (北京迪恩康硕科技发展有限公司), National High-Tech Enterprise, optoelectronic R&D + sensor structure design + demodulator system integration.
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Product Name: Armored FBG Array Strain Sensing Cable
Alternate Terms: Armored weak FBG strain cable, quasi-distributed fiber grating strain sensing cable, SMF-28 ultra-weak grating array armored jacket, EMI-immune structural strain cable for SHM, perimeter intrusion FBG array cable, DEAN Technology armored FBG strain rope
Sensing class: Quasi-distributed / long-gauge average strain (gauge length = grating spacing, e.g. 1 m long-gauge suppresses local defect chirp)
Spatial resolution: Defined by grating pitch (0.5 m / 1 m / 2 m custom), not by interrogator sampling
Core Applications:
Civil SHM: Bridge deck strain mapping, tunnel lining deformation, dam body settlement, railway track-bed stress
Energy & Pipe: Oil/gas pipeline strain + leak-induced strain anomaly, thermal pipeline expansion monitoring, power cable tunnel deformation
Perimeter Security: Fence-line intrusion detection via strain step response, buried boundary warning
Industrial: Storage tank foundation settlement, crane girder fatigue, high-EMI plant structural monitoring
Companion SKUs on dsc.net.cn: Armored FBG Array Temperature and Strain Monitoring Cable, Double-Layer Steel Stranded Armored Buried Sensing Cable, FBG demodulators, traditional discrete FBG sensor strings
Metro Tunnel Lining: Instead of 60 discrete FBG tags, one 1.2 km armored UWFBG cable with 1 m pitch = 1200 strain points along the invert and springline. Early convergence shows as a smooth wavelength-slope curve; a local spall still registers because neighboring 1 m gauges average the strain field. Interrogator at tunnel portal, no in-tunnel electronics.
Prestressed Bridge Deck: Cable bonded to soffit with epoxy, 0.5 m pitch. Live-load deflection during overload truck passage appears as a traveling strain wave; long-term creep separated from thermal expansion via companion temperature array. EMI immunity means sensors sit 2 m from the traction rail without signal contamination.
Pipeline Strain + Intrusion: Buried parallel to a 273 mm steel oil line, 1 m pitch. Soil settlement bends the cable → wavelength shift; third-party excavation near the right-of-way produces a localized strain step → perimeter alarm. Armored jacket survives backfill and rodent gnaw (with steel-strand variant).
Substation Structure: Electrical strain gauges useless 5 m from a 220 kV busbar; UWFBG array reads gantry foundation settlement and steel-frame thermal drift with zero grounding concerns.
When specifying Armored FBG Array Strain Sensing Cable — Thousands Of Weak Fiber Bragg Gratings Densely Inscribed On Single Mode Fiber SMF-28 Packaged In PE PU Teflon Mid Layer And Mechanical Armored Outer Jacket For Distributed Quasi Distributed Strain Sensing Structural Health Monitoring Bridge Tunnel Dam Pipeline Perimeter Intrusion Warning EMI Immune High Sensitivity Custom Spacing FC APC Connector DEAN Technology Beijing Dian Kongshuo Science And Technology Development Co Ltd:
✅ Grating class — confirm ultra-weak (reflectivity 0.01–1%), not discrete strong FBG string; ask inscription uniformity (±0.5 nm center wavelength tolerance).
✅ Pitch & length — 0.5 / 1 / 2 m spacing; total length 500 m / 1 km / 2 km per reel; custom pitch per structural model.
✅ Fiber & coat — SMF-28 inner, PE/PU/Teflon mid-layer ≤1.5 mm OD, armored outer 3/4/5 mm; pull strength >100 kpsi class.
✅ Termination — FC/APC standard, SC/LC optional; factory-polished, OTDR trace supplied.
✅ Interrogator match — confirm C-band channel count, scan rate (≥1 kHz for dynamic), and wavelength range covers inscribed grid (e.g. 1528–1568 nm).
✅ Temperature coupling — pure strain cable vs temperature-compensated dual-array; specify if thermal decoupling needed.
✅ Vendor doc — DEAN Technology inscription process sheet, armored cable cross-section drawing, custom-SKU confirmation, 90-day technical support clause.
The Armored FBG Array Strain Sensing Cable — Thousands Of Weak Fiber Bragg Gratings Densely Inscribed On Single Mode Fiber SMF-28 Packaged In PE PU Teflon Mid Layer And Mechanical Armored Outer Jacket For Distributed Quasi Distributed Strain Sensing Structural Health Monitoring Bridge Tunnel Dam Liquid Pipeline Perimeter Intrusion Warning EMI Immune High Sensitivity Custom Spacing FC APC Connector DEAN Technology Beijing Dian Kongshuo Science And Technology Development Co Ltd replaces the question "where do I put the 40 strain gauges" with "what spatial resolution do I want per kilometer". Ultra-weak grating density turns one fiber into a 2000-point strain ruler; the armored PE/PU/Teflon-plus-mechanical jacket turns that ruler into a pull-through field instrument that survives trench backfill, tunnel humidity, and substation EMI; and a manufacturer like DEAN Technology (Beijing Dian Kongshuo) that controls inscription, encapsulation, and demodulator together removes the integration risk EPC teams usually absorb when buying fiber from one vendor and gratings from another. For long infrastructure where blind zones are liabilities—bridges, tunnels, dams, pipelines, perimeter fences—this is not a premium sensor, it is the only sensing topology that treats strain as a continuous field instead of a set of guessed points.
