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A company of the BRUGG Group

Sensing Technology.

A company of the BRUGG Group2Basic_Sensing_e.ppt / ad

Applications.


LASER

λ 0 [nm]

λ [nm]

Inte

nsity

λ 0

Laser.


LASER

λ 0 [nm]

TTT

T

Stokes Components

λ [nm]

Anti Stokes Components

Inte

nsity

RamanRamanRaman Brillouin Brillouin

Rayleigh

Rayleigh, Brillouin, Raman Scattering.


Optical fiber <> Silicium dioxyde SiO2.

Silica: SiO2

O – Si - O

LASER probe

Raman effect

Back scattered light AS & S


Measuring system.

Raman effect. For temperature sensing only. Intensity change method. Uses multimode fibres. Cost effective solution for distances up to 8-10 km.

Brillouin effect. For Temperature and strain sensing. Frequency shift method. Uses singlemode fibres. For distances up to 30 km and more. Can be combined with singlemode communication transmission.


Raman vs. Brillouin sensingtechniques. Raman-based temperature sensing.

Raman scattering is sensitive only to temperature. Low scattering intensity. Requires multimode optical fibers (high numerical

apperture). Very efficient for distances up to 8km distance. Issues related to intensity-based techniques. Availability of multimode fibers?


Raman vs. Brillouin sensingtechniques. Brillouin-based temperature/strain sensing.

Brillouin scattering is sensitive to strain and temperature. Possibilities to be stimulated through dedicated optical

processing. Requires singlemode optical fibers. Offers greater distance range (up to more than 30km). Advantage of frequency-based measurement technique. More advanced measurement system. Compatibility with singlemode fiber communication system

(sensing can be multiplexed with data transmission.


An optical fiber as a sensing element. The DTS is based on the measurement of the Brillouin

Scattering characteristics. Natural scattering process associated to the propagation of light. Intrisic properties of the fiber. Interaction of light with the propagation medium. Attributed to the presence of inhomogeneities associated to

acoustic waves in the silica (acoustic phonons).

Léon Brillouin (1889-1969):

French physicist Léon Brillouin pioneered the field of quantummecanics and solid state physics. He was the first to describe theproperties of thermally excited acoustic waves in solids and liquidsand their interactions with light, leading to the scattering of light.


Methods.Raman for temperature monitoring.

Inte

nsity Is Ia T

Optical fibre

Light inputBack scattered light

Transmitted light

Analysis ofAnalysis ofback scatteredback scatteredspectrumspectrum


Measuring methods.Raman based temperature measures.

Intensity of back scattered laser pulse temperature.

Time delay of back scattered laser pulse location.

Temperature profile can be recorded and displayed along the whole optical fibre length.


Methods.Brillouin for temperature monitoring.

Frequency domainanalysis

Optical fibre

Light inputBack scattered light

Transmitted light

Analysis ofAnalysis ofback scatteredback scatteredspectrumspectrum


Measuring methods.Brillouin based temperature measures.

Frequency shift of back scattered laser pulse temperature.

Time delay of back scattered laser pulse location.

Temperature profile can be recorded and displayed along the whole optical fibrelength.


Applications & markets.


Applications & markets (general). Oil and gas industries.

Pipelines, storage tanks, off-shore platforms, subseaexploration…

Civil engineering. Structural monitoring (dams, dikes, highways, ...).

Surveillance and Safety systems. Tunnels, buildings, heating systems, waste disposal sites, power

cables, air-con systems, dikes Land slide.

Environmental sciences. Telecommunications.

Maintenance activities on fiber cables.


Advantages of FO temperaturemonitoring. Continuous, distributed temperature sensing with high

resolution along sensor cable. Many possible variants for disposition of the system. Installation possible on location, which are not

accessible afterwards (ex. dams). No influence by electro-magnetic fields. Easy installation. No influence of temperature field by process of measure. No active electronic components are necessary

(protection against explosion).


Temperature monitoring. Temperature monitoring sensor.

Robust design. Stainless steel armouring. Up to 8 fibers in SS loose tube. -55°C to 85°C temperature range (standard). -65°C to 300°C temperature range (extreme Temp version). Flame retardant non-corrosive (FRNC) and other sheath options.

Optical fibres

Stainless steel wires

Stainless steel loose tube

Sheath


Fire Prevention.


Applications. Metro & railway stations. Metro trains. Parking houses. Bus terminals. Airplane hangars. Mining tunnels. Road tunnels. Elevator shafts.


Metro & railway stations.


Metro trains.


Parking houses.


Bus terminals.


Airplane hangars.


Mining tunnels.


Road tunnels.


Heat detection system.

Features & benefits. 8 km, 16km and 24km range. Robust and easy to install sensing cables. Automatic unattented operation. Rapid detection and localization of fire. Interface with standard control systems. Automatic generation of alarms signals. Remote control and configuration.


Application example.Fire protection in tunnels. Quick detection of

hot spots. Detection of

location of fire. Coordination of

rescue andintervention againstfire can be done ina quick andefficient way.


Elevator shafts.


Power generation & distribution.


Applications.

Power cables in plants & distribution. Transformers in power plants. Power cable tunnels/ducts.


Power cables in plants & distribution.


Transformers in power plants.


Power cable tunnels/ducts.


Process control.


Applications.

Pipeline leakage. Monitoring of ovens or storage tanks. Elevator shafts. Metro trains. Conveyor belts. Cold stores.


Pipeline leakage.


Other applications. DTS Leakage Detection System for pipelines, dams, dikes,

etc. Features & benefits.

Up to 30km distance range. Estension to more than 250 km

with a single instrument and DRM. Robust and easy to install sensing

cables. Automatic unattented operation. High accuracy temperature monitoring

(< 0.5°C) for reliable leak detection. Automatic generation of alarms signals. Remote control and configuration capabilities.


Sensing cable installation.

Cable installation at the time of the oil pipelineconstruction.

Pipeline constructionand sensing cableembedding:

The sensing fiber cableis burried in the sandprior to the oil pipelinelaying.


Pipeline leakage.


Maintenance activities on pipelines.

Temperature monitoring during pressure tests on apipeline.

Bi-annual pipeline integrity check. High accuracy temperature monitoring

on 15 km sections of pipe.


Reduce costs ofmaintenance andoperation.

Intervention can beplanned in a perfectway (just in time).

Monitoring of ovens or storage tanks.

0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.00.0

1.0

2.0

65 70 75 80 85 90 95 100 105 110 115 120 125


Elevator shafts.


Metro trains.


Conveyor belts.


Cold stores.


Environmental protection.


Applications.

Dams/barrages. Dike dams.


Dams/barrages.


Temp. monitoring in a dam/barrage. Temperture monitoring of the concrete during setting.

Overheating introduces microcracks (T > 50°C). dam: 17 m added to the original height of the dam in order to

increase the lake capacity.


Temp. monitoring in a dam/barrage.

Setup of the sensing fiber in the concrete layer(15m x 20m).



Setup of the sensing fiber in the concrete layer(15m x 20m).



Temperature evolution over 6 months.


Dike dams.


River dikes monitoring – advancederosion warning. Possibility to cover long distances. Possibility to locate erosion problems (early

warning) or overflow before catastrophic dikefailures.

RiverDike Dike


Geothermal investigations.


Applications.

Geothermal drilling.


Geothermal drilling.


Questions, Remarks?


Thank you for

your attention!

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