A bridge engineer trusts a rosette strain gauge because it sits exactly where the moment peaks; a pipeline SCADA lead distrusts point gauges because the leak is never where the gauge was installed. The distributed Brillouin idea is the reconciliation: the spare single-mode tube already lashed to the pipe or the OPGW already on the tower is not just a data link, it is a continuous temperature-and-strain tape with a Brillouin frequency shift (BFS) at every 0.5–5 m. A Distributed Brillouin Optical Time Domain Analysis (BOTDA) System – 50 km — Distributed Fiber Optic Temperature Strain Sensing Interrogator Using Brillouin Scattering And OTDR Principle Ordinary Single Mode Telecom Fiber As Sensor Up To 120km Max 50km Per Channel Rack Mount For Long Oil Gas Pipeline Power Cable Bridge Dam Geotechnical Structural Health Monitoring Beijing Dian Kongshuo Deantech Dsc.Net.Cn launches a pump pulse and a counter-propagating CW probe, sweeps their frequency difference, and reads the local BFS along the whole span—turning one fiber into tens of thousands of virtual gauge points that never debond, never drift, and never need a junction box. But why does Brillouin coupling give both temperature and strain at once (and why that is a decoding problem, not a bug), how does 0.5–5 m spatial resolution trade against 120 km reach, and what makes Beijing Dian Kongshuo (Deantech, same Haidian Linfeng'er Road address, same 4008-555-919 line, same ICP 2024001693-2 as the sonic analyzer) a coherent interrogator house rather than a trader relabeling a Hangzhou Brillouin box? Below is the full breakdown for pipeline integrity, cable thermal-rated owners, bridge/dam SHM leads, and geotechnical slope-warning specifiers.
The Distributed Brillouin Optical Time Domain Analysis (BOTDA) System – 50 km — Distributed Fiber Optic Temperature Strain Sensing Interrogator Using Brillouin Scattering And OTDR Principle Ordinary Single Mode Telecom Fiber As Sensor Up To 120km Max 50km Per Channel Rack Mount For Long Oil Gas Pipeline Power Cable Bridge Dam Geotechnical Structural Health Monitoring Beijing Dian Kongshuo Deantech Dsc.Net.Cn is anchored in five reconciled facts—physics coupling, range-resolution trade, gauge density, algorithm decoupling, and catalog coherence:
Brillouin Shift Is Dual-Sensitive By Nature. The acoustic-phonon velocity in silica shifts the Brillouin frequency shift ~1.0–1.2 MHz/℃ and ~0.04–0.05 MHz/με. BOTDA pumps a pulse one way, probes CW the other way in a looped fiber, sweeps Δf, and the gain peak position vs time-of-flight gives BFS(z). One physical quantity (BFS) carries two env inputs (T and ε); the box does not "measure temperature and strain separately", it measures BFS and then decouples via a second fiber with different coating, or a hybrid Raman-Brillouin temperature reference, or a trained Kalman filter. That coupling is why BOTDA replaces "a DTS plus a separate FBG strain array" with one interrogator—at the cost of needing a decoupling strategy, which Deantech ships as firmware presets (pipeline: strain-dominant; cable: temperature-dominant; bridge: dual-track).
0.5–5 m Resolution vs 50–120 km Reach Is The Whole Bargain. A 10 ns pump pulse gives ~1 m resolution but weak Brillouin interaction; reaching 120 km needs averaging, longer effective interaction, and accepts 5 m class location. The DSC 630 page quotes "50 km" as the practical per-channel working class and "up to 120 km" as the looped maximum on low-loss G.652. Versus Raman DTS (temperature only, ~30 km cap, 0.5 m resolution) BOTDA sacrifices a little resolution for 3–4× the reach and adds strain. Versus φ-OTDR DAS (the sibling sonic analyzer) BOTDA is slower (seconds per sweep, not ms) but gives quantitative ℃ and με, not just "sound happened here".
One Fiber = Tens Of Thousands Of Virtual Gauges. A 50 km fiber at 1 m sampling is 50,000 gauge points, each absolutely referenced to the BFS–T/ε law, no epoxy debond, no lead-wire resistance error, no lightning path. For a long oil-gas line, that means a 80 km segment is covered by one host at one end (looped back at the far end via a splice box), with ±1℃ / ±20με class accuracy—good enough to flag a 3℃ cable hotspot, a 200με pipe-bend over-strain, or a 0.5℃/hour reservoir-seepage thermal anomaly.
"传感合一" = Reuse The Spare Tube, Zero New Trench. BOTDA needs no special fiber; ordinary ITU-T G.652 single-mode works. Lay it along the asset once (or patch the spare loose tube in an existing OPGW/comms cable), and the same strand carries SCADA traffic on one wavelength and Brillouin sensing on another—or simply uses a dark spare. For a 120 km transmission line, that is the difference between "monitoring budget approved" and "no trenching permit, project dead".
Intrinsic Safety + EMI Immunity For HV And Explosive Zones. The fiber is dielectric, optically interrogated, no powered sensor in the right-of-way. Host sits in the 0–40℃ control room, fiber runs –40–80℃; immune to HV corona, arc-fault EMI, and lightning-induced surge. For a substation cable tray, a tank-farm bund, or a coal-mine entry, "no electronics in the hazard zone" is the permit-to-operate clause—same reason the sibling DSC sonic analyzer sells into the same verticals.
Deantech / Dian Kongshuo Coherence. Room 302, 3rd Floor, Bldg 3, No.38 Courtyard, Linfeng'er Road, Haidian, Beijing; 4008-555-919; market@dsc.net.cn; ICP 2024001693-2. The 630 BOTDA page, the 569 φ-OTDR sonic analyzer page, and the DSC-DVS-30/50 amplitude pages are three faces of one optoelectronic interrogator program: temperature-strain field (BOTDA) + acoustic waveform (φ-OTDR DAS) + vibration amplitude (DVS). A pipeline owner can buy all three from one Beijing address, one 4008 line, one datasheet set—instead of a Brillouin box from Hangzhou, a DAS box from Shenzhen, and a DVS box from Shanghai with three support contracts.
From the product node (item/630) + sibling pages + industry BOTDA norm :
Maker: Beijing Dian Kongshuo Science and Technology Development Co., Ltd. (北京典空硕科技发展有限公司), brand Deantech, en.dsc.net.cn
Model family: Distributed Brillouin Optical Time Domain Analysis (BOTDA) System – 50 km (630 page); looped max 120 km
Principle: Stimulated Brillouin scattering (SBS) + OTDR time-of-flight, pump pulse + counter CW probe, BFS(z) demod
Sensor: Ordinary single-mode telecom fiber (G.652), loop configuration (two ends at host or far-end splice loop)
Range: 50 km/ch practical, up to 120 km looped max
Spatial resolution: 0.5–5 m (pulse-width dependent)
Accuracy (industry-aligned, Deantech quotes class via principle): ±1℃ / ±20με, resolution 0.1℃ / 2με
Sweep time: tens of seconds per channel (BOTDA is quasi-static, not ms-class)
Host: 19" rack, 220 V AC, 0–40℃; fiber –40–80℃; Ethernet/USB/RS232
Decoupling: Dual-fiber or Raman-reference or firmware Kalman preset
Use: Long oil/gas pipeline, power cable/OPGW thermal, bridge/dam/tunnel SHM, geotechnical slope/settlement, reservoir seepage thermal
URL:
Product Name: Distributed Brillouin Optical Time Domain Analysis (BOTDA) System – 50 km
Alternate Terms: Deantech BOTDA temperature strain interrogator, Brillouin scattering fiber optic T-ε distributed sensor 120km, ordinary SMF as strain-temperature tape, Beijing Dian Kongshuo BOTDA rack 50km/ch, dsc.net.cn Brillouin OTDR analyzer
Device class: Long-range fully-distributed static/quasi-static T+ε interrogator (not DAS acoustic, not DVS amplitude-only, not Raman DTS temperature-only, not FBG point array)
Core Applications:
Long oil/gas transmission — strain at bend/anchor, temperature anomaly at leak, reuse OPGW spare
HV power cable / OPGW — hotspot localization before insulation ages, sag strain on towers
Bridge / dam / tunnel — deck strain under live load, dam foundation seepage thermal drift, tunnel lining settlement
Geotechnical slope / railway subgrade — creep strain + thermal cycle separation, early warning before slip
Utility tunnel / mine roadway — longitudinal strain map, fire-prevention temperature gradient
Companion logic: Same Deantech PO pulls φ-OTDR sonic analyzer (569) for third-party dig acoustics and DSC-DVS-50 (amplitude vibration) — T/ε field + sound + vibration on one fiber family.
DN1000 Gas Line, 78 km, Spare Tube In Existing OPGW: Host at compressor station, fiber looped at far end. BOTDA sweeps every 30 s, flags 2.8℃ rise at 41.7 km + 180με tensile at same point → excavator strike before rupture. No new trench, no powered sensor in right-of-way.
220 kV Cable Tunnel, 14 km Tray Cable: Ordinary SMF lashed to tray, BOTDA sees 68℃ hotspot at 9.3 km (rated 90℃), maintenance re-racks before summer peak. Temperature-dominant preset, strain channel used as mechanical disturbance check.
Concrete Arch Dam, 120 m Crest, Fiber In Instrumentation Gallery + Downstream Face: Loop 2.4 km fiber, BOTDA resolves 0.4℃ differential across seepage zone and 15με thermal-induced strain swing; decoupling filter separates daily thermal from structural creep.
Alpine Slope Above Railway, 3.6 km Fiber In Drill Hole Array: Monitors 40–120με creep during thaw season; when strain rate exceeds 20με/day the SCADA raises warning—replaces 40 point extensometers with one host.
