Nerve-Sensors connected to appropriate optical interrogator provide high-quality distributed fibre optic sensing (DFOS). They can measure different physical quantities continuously over its entire length, including strains, cracks, displacements (shape changes), temperatures or vibrations. Typically, Nerve-Sensors are made from composites ensuring their high flexibility, accuracy, robustness and durability.
As opposed to layered sensing cables, monolithic Nerve-Sensors offer considerably improved measurement quality, encompassing all of the positive attributes of layered sensing cables and more, without any of their drawbacks. This includes a monolithic cross-section without any intermediate layers, ensuring no slippage and debonding effects for accurate strain transfer; a composite core without plastic or steel elements, providing a much wider strain range; and a rough/ribbed outer surface for perfect bonding with the surrounding material. Read more “Layered cables vs. DFOS sensors”.
Our EpsilonSensor and EpsilonFlat are made from polyester fibre + epoxide. The EpsilonRebar is made from glass fibre + epoxide. The 3DSensor is usually made from PLFRP + PE (polyester fibre and epoxide), but also different materials and versions are available depending on the application. Please contact us for more details.
We usually use circular cross section for strain sensors (EpsilonSensor, EpsilonRebar, EpsilonGraph) embedded in concrete or soil. For surface strain readings we recommend rectangular section of the EpsilonFlat. Also, the 3DSensor is designed with a rectangular cross-section to avoid twisting and facilitate installation.
Our DFOS sensors can be glued to almost any surface using two-part epoxy, including concrete, steel or composite. In addition, Nerve-Sensors can be installed in existing concrete structures in near-to-surface grooves filled with epoxy or mortar.
Splicing is done at the factory before they are shipped to you by our expert team. Although the optical splicing itself is the same like in telecom cables, the whole process (including the extraction and protection of the fibre) differs due to the bespoke nature of the composite and monolithic material core of Nerve-Sensors. In some circumstances, preparation of the sensors can be carried out on-site, or our team can train your technicians on how to extract the fibre from our sensors and how to protect the connection.
Typically, we work with standard telecom single-mode fibres SM9/125 with acrylate primary coating. It ensures very low attenuation and facilitates the splicing while keeping precise strain transfer when integrated with the monolithic composite core. For EpsilonGraph, we are also using multimode fibres which perform better with distributed temperature sensing (DTS). As a producer, we can easily apply other type of fibres to our sensors, e.g. in polyimide coatings or with FBG arrays.
Typically, we have 2 fibres in our strain sensors (EpsilonSensor, EpsilonRebar, EpsilonFlat, EpsilonGraph) and 4 fibres in the displacement (shape) 3DSensors. This numbers can be doubled for special projects requiring high redundancy or simultaneous connection to different DFOS-based interrogators. We have possibility to provide sensors with different fibres inside, e.g. single-mode, multi-mode or with FBGs array.
Yes, we cut Nerve-Sensors to your required length, and then attach (splice) pigtails with your defined length. Typically, the pigtail length is no higher than 15 m. Each connecting pigtail can be additionally protected in a PE tube for field applications with no additional cost.
Definitely, we always test each sensor, including the pigtail, before we ship it. Wherever possible, we also connect the sensors to the same interrogator (or one with similar performance) as the one used by the customer (in addition to the regular reflectometer check).
For strain sensors embedded inside concrete or soil, we always use external braid (uni- or bi-directional) to improve the bonding properties and transfer of structural strains to the fibre. When gluing on the surface, we can use sensors with a smooth outer surface (and flat section). For shape sensing, we do not use an outer braid, because the possible longitudinal slippage of the sensor does not influence the displacement calculations.
From -20 to +80°C, but higher ranges are available on request. It is worth noting that EpsilonRebar can even withstand short-term high temperatures during asphalting.
EpsilonSensor has the highest strain range available on the market, which is ±4% (±40 000 µε). Symbol “±” means, that it works both in tension and compression, without need for pretensioning.
Our sensors are delivered in coils, securely packed into reinforced cardboard boxes. Sensors are relatively light and compact ensuring fast and more affordable shipment by air.
Yes, we cut our sensors to your required length, including the pigtails which will connect sensors to the optical interrogator. In some circumstances, we can train your team how to extract the fibre from our sensors, splice it and protect if you prefer to cut to a specific measurement at your location.
The maximum lengths are specified in technical datasheets for each sensor type. Usually, the limiting factors are the capacity requirements for transport and installation conditions. In cases where longer lengths are required, sections can be connected in series.
No, Nerve-Sensors work perfectly in both compression and tension without the need for pre-tensioning.
Yes, they can, and they don’t need to be pre-tensioned for that purpose. When we think about compression zone measurements, we should only be aware of buckling. However, when sensors are embedded in soil or concrete, or continuously bonded to the surface, this problem is automatically removed.
No layers means no internal slippage and the best possible strain transfer from the structure to the sensing fibre. Only trusted solutions should be used for monitoring and structural safety assessment. Monolithic design of our sensors without intermediate layers is crucial for:
- detecting the minor strain changes (e.g. initiation of cracks),
- precise measurement of very high strain values in near-to-failure state,
- required repeatability during cyclic changes of mechanical and thermal loads over years,
- creating reliable infrastructure for future developments of optical interrogators.
Read more about the monolithic design of our sensors https://doi.org/10.3390/s22228713
Crack detection and analysis is definitely one of the main applications of our solutions, especially for the EpsilonSensor. Its monolithic design and very high strain range make it a perfect tool for crack identification, localisation and width estimation (without fear of sensor breakage).
Read more in the articles:
Nerve-Sensors were originally designed to work with DFOS interrogators. However, different types of fibres can be integrated into the composite core, including those with FBGs arrays at any spacing (we can provide FBG arrays produced by ourselves according to your requirements). It is possible and beneficial to create hybrid systems and sensors, where one fibre is used for periodical DFOS readings, and the second fibre (or fibres) is connected to an FBG interrogator for automated measurements. Please contact our team for further details.
3DSensor
The 3DSensor core contains 4 optical fibres arranged near the corners of the rectangular cross-section. Given a certain distance from the neutral axis of the core, the fibres are sensitive to strains caused by bending (actions perpendicular to the sensor axis). From the measured strain profiles and known fibre spacing, local curvatures can be directly determined. Then, assuming appropriate boundary conditions, vertical and/or horizontal displacements (shape changes) are calculated.
You can find more information in the article: https://doi.org/10.3390/s21155089
There is no direct answer as the above parameters depend on many factors, including:
- spacings between the fibres inside the sensor, which depend on sensor’s dimensions (height and width)
- spatial resolution of the applied interrogator
- strain accuracy of the applied interrogator
- boundary conditions (e.g. simply supported beam, cantilever, constrains by soli, etc.)
- length of the sensor
- predicted deformation shape (true strain profiles and values)
- accuracy of positioning the sensor during installation (e.g. without twisting)
Typically, we perform analytical and/or numerical simulations based on the pre-defined conditions of a specific project.
Yes. We have 4 fibres in the cross section of the sensor. We use the top and bottom fibres to calculate vertical displacements and the left and right fibres to calculate horizontal displacements.
Each installation should be approached individually, depending on the specifications and conditions of the project. Typically, protection in the form of sand or soft ground banding is beneficial. Local pressure of sharp aggregate should be avoided. Please contact our team to discuss the details.
EpsilonSensor
The selection of the sensor depends on the installation conditions and the predicted strain to be measured. EpsilonSensor is universal solution for both laboratory and field projects. It can be freely shaped and, thanks to its elastic core, high strain range and low elastic modulus, it is perfect for strain sensing without strenghtening the element, as well as for precise crack detection and analysis. Typically produced in Ø3mm diameter, it is also available in Ø5mm for more demanding field projects. On the other hand, EpsilonRebar has the same parameters as GFRP rebars, and can also be treated as structural reinforcement. It is more robust thanks to its higher stiffness and strength. In short, it usually works in (relatively) straight sections and in challenging field conditions e.g. in geotechnical applications, boreholes injected with concrete, asphalt layers or in densely reinforced structures.
The main difference lies in the material used to create the sensors and their mechanical parameters. EpsilonRebar acts as a Glass Fibre Reinforced Polymer (GFRP) reinforcement with a Young’s modulus of 50 GPa and a maximum strain of ±2%. EpsilonSensor has a significantly reduced modulus (3 GPa) with an increased range of up to ±4%. Assuming typical diameters of Ø5 mm for ER and Ø3 mm for ES – this gives an almost 50 times reduction in axial stiffness EA. You can find more information in the article: https://doi.org/10.1016/j.measurement.2023.113480
EpsilonRebar
The selection of the sensor depends on the installation conditions and the predicted strain to be measured. EpsilonSensor is universal solution for both laboratory and field projects. It can be freely shaped and, thanks to its elastic core, high strain range and low elastic modulus, it is perfect for strain sensing without strenghtening the element, as well as for precise crack detection and analysis. Typically produced in Ø3mm diameter, it is also available in Ø5mm for more demanding field projects. On the other hand, EpsilonRebar has the same parameters as GFRP rebars, and can also be treated as structural reinforcement. It is more robust thanks to its higher stiffness and strength. In short, it usually works in (relatively) straight sections and in challenging field conditions e.g. in geotechnical applications, boreholes injected with concrete, asphalt layers or in densely reinforced structures.
The main difference lies in the material used to create the sensors and their mechanical parameters. EpsilonRebar acts as a Glass Fibre Reinforced Polymer (GFRP) reinforcement with a Young’s modulus of 50 GPa and a maximum strain of ±2%. EpsilonSensor has a significantly reduced modulus (3 GPa) with an increased range of up to ±4%. Assuming typical diameters of Ø5 mm for ER and Ø3 mm for ES – this gives an almost 50 times reduction in axial stiffness EA. You can find more information in the article: https://doi.org/10.1016/j.measurement.2023.113480
Read more: When to use the EpsilonSensor and when to use the EpsilonRebar fiber optic sensor?
EpsilonRebar has the same parameters as standard Glass Fibre Reinforced Polymer (GFRP) reinforcement for concrete. Therefore, it can be used as smart GFRP reinforcement bars. However, this is not the same as conventional steel bars. GFRP has almost 3 times better tensile strength (1400 MPa) than steel, but 4 times smaller elastic modulus (50 GPa).
EpsilonPeak
FBG Interrogators, unlike DFOS reflectometers, do not require special terminations. As standard, we sell the sensor with an unterminated optical fibre at the end. If required, we can splice pigtails terminated with suitable connectors up to a given length according to customer requirements.
As a standard, the minimum distance between the ends of our FBGs is 10 mm. Also check the question “Is it possible to modify the length of the FBG?”.
Currently, we produce gratings in the range of 1467-1607 nm. A list of possible wavelengths is available on request.
Ultimately, all FBGs manufactured are characterized by geometrically uniform distribution of the refractive index (Uniform FBG). If necessary, it is possible to produce apodized FBG.
Distances in the order of 10 km should not be a problem, although it depends on the interrogator model used and the number of FBGs. Also keep in mind the shift of the grating’s central wavelength with its distance from the interrogator, the so-called distance compensation. Let’s talk about your project – contact us.
From -30°C to +70°C – this is the typical temperature range.
The maximum length of the patchcord can be up to several kilometres and depends on the type of interrogator. Let’s talk about your project – contact us.
The basic method of installing FBG sensors is to glue them directly on the surface of the structure or in a groove. The latter method is more advantageous in terms of effective strain transfer from the measured element to the sensor. Feel free to contact us and we can help you choose the right sensor and installation method.
It is also possible to install FBG sensors during the production of composite elements using infusion, pultrusion and other processes.
We offer FBGs with physical lengths from 4 to 10 mm. As part of our standard offer we produce FBG with a length of 10 mm.
At the moment we can apply 13 different FBGs on one optical fibre. A detailed list of available wavelengths is given in the response to your inquiry.
We offer templates that allow you to precisely place FBGs in specific locations on the structure and ensure that you always have the same bond when gluing on the surface.
Yes. Our FBG works great in a wide range of metals, including not only elastic range, but also plasticization (yielding zone).
Yes. Our FBG performs well in measuring non-uniform strain field, so it is a perfect tool for monitoring the condition of heterogenous composite elements.
Yes, our FBG work very well, including in tests of concrete or composites where cracking is present.
Each of our FBGs comes with a calibration card in which you can find all the necessary coefficients.
Yes they can, but the frequency of strain (or temperature) changes should be consistent with the frequency of a given FBG interrogator. Let’s talk about your project – contact us.
EpsilonFlat
EpsilonFlat is the younger sibling of the EpsilonSensor with the same material properties (low modulus and high strain range). The main difference is in the shape of thecross section: instead of being circular, EpsilonFlat is rectangular to facilitate bonding to flat surfaces, as well as to increase the bonding area. Moreover, EpsilonFlat is manufactured without an external braid. Thanks to the above features, it is a perfect diagnostic soluti on to apply on pipelines or railways (check example – case study High-speed Railway Line: Static and Dynamic Distributed Measurements). – https://nerve-sensors.com/case_studies/high-speed-railway-line-static-and-dynamic-distributed-measurements-2/
EpsilonFlat is meant for gluing on flat structural surfaces (e.g. concrete, steel, composite), assuming that the entire sensing path is a straight line without loops.
EpsilonGraph
EpsilonGraph has been developed on the basis of the EpsilonSensor, keeping all its advantages in terms of mechanical strain sensing. In additi on, the core of EpsilonGraph contains a certain amount of graphite to improve its thermal conducti vity. This is also the reason why the sensor is black.
EpsilonGraph is parti cularly useful in projects where rapid temperature changes are the most important parameter to measure. It is perfect for detecting temperature-related leaks or monitoring the thermal-shrinkage behaviour of young concrete during its hardening.
Hybrid systems synergise the advantages of periodic distributed fibre optic sensing (DFOS) with automated measurements using spot sensors (e.g. FBGs or vibrati ng wiregauges). The systems provide comprehensive knowledge about the structure’s operati on and enable optimizati on of the informati on obtained.
Hybrid systems are primarily:
- a combination of the possibilities offered by automatic spot sensors and geometrically continuous fibre optic measurements DFOS (distributed fibre optic sensing)
- providing extended analysis of changes in the structure over time (spot sensors) with direct detection of local damage (fibre optic sensors)
We are experienced in the design, installation and maintenance of hybrid monitoring systems. We have completed many projects using independent measurementtechniques, e.g. fibre optic sensors with inclinometers or automatic point sensors. Please feel free to contact us for more information at contact@nerve-sensors.com
Hybrid systems work well for safety monitoring of a wide variety of objects:
- hydrotechnical and geotechnical structures
- linear infrastructure
- large-areas
- industrial infrastructure
- and others
We are experienced in designing, installing and maintaining hybrid monitoring systems. Do you have questions? Contact us at contact@nerve-sensors.com
Definitely, hybrid systems can generate signifi cant savings. Why? There are several reasons:
- the low cost of fibre optic sensors
- no need to purchase expensive interrogators
- investment “deferred over time” – installati on of fibre optic sensors at the constructi on stage of the structure, while taking measurements at a later stage
- cost optimisati on over the entire life cycle of the structure
We are experienced in designing, installing and maintaining hybrid monitoring systems. Do you have questi ons? Contact us – contact@nerve-sensors.com
Data from two independent measuring techniques increases the reliability and credibility of the entire system. The obtained data can be compared and used for further, extended structural safety analysis.
We are experienced in designing, installing and maintaining hybrid monitoring systems. Do you have questi ons? Contact us – contact@nerve-sensors.com
Hybrid systems can be installed at any stage of a structure’s life. The system offers great possibilities in the selection and configuration of individual sensors.
Practically speaking, no. Hybrid systems provide great fl exibility both at the design and implementati on stages. They enable:
- to continuously adapt the system (e.g. type, number, location and configurati on of sensors) to changing conditions of the design, construction or operation of the structure
- the freedom to configure sensors for the specific needs of a given project
- in the case of observing irregularities, the ability to trigger additional fibre optic sessions by spot sensors (triggers), based on a substantive and objective justification
We are experienced in designing, installing and maintaining hybrid monitoring systems. Do you have questions? Contact us – contact@nerve-sensors.com
The most convenient installation includes embedding inside the new structures (concrete or soil). However, for existing and ageing infrastructure we propose near-to-surface installation inside grooves or by gluing sensors directly on the surface. Each project should be treated individually. We will gladly help you assess all options.
Yes – this approach has multiple advantages, including:
- possibility to start measurements from a true zero strain-stress state
- the best strain transfer through bonding (without additional mounting elements or adhesive layers)
- natural protection against mechanical damages during the entire operational time frame
- protection from direct sunlight – easier thermal compensation
- the best aesthetics (no visible elements on the structure)
Yes, Nerve-Sensors (like all optical fibre sensors) are sensitive to both mechanical and thermal strains. Thus, thermal compensation is required for appropriate data interpretation. For correct thermal compensation you need to know:
- temperature change (ΔT) over length,
- thermal response of Nerve-Sensors, which is linear (we provide thermal compensation coefficient),
- how to interpret compensated data for correct structural assessment.
All the above aspects have been discussed by our team in the publication: https://doi.org/10.1016/j.measurement.2024.115280
Yes. In that case we recommend creating near-to-surface grooves for concrete or glueing directly to the steel, composite or timber surface. Sometimes it can be beneficial to apply additional protection against direct sunlight.
We prefer to install sensors inside surface grooves. It increases the bonding surface (compared to glueing on surface), but also provides better mechanical and thermal protection, as well as improves aesthetics.
Yes. EpsilonRebar is able to withstand short-term high temperatures during asphalting.
Yes. We usually glue the sensors to the existing steel or composite surfaces.
This depends on the surface material being monitored, the operating conditions and the specific requirements of a particular project. We test different adhesives in our own laboratory to specify, for example, modulus of elasticity, strength or adhesion to different materials. Contact us – we can provide you with suggestions and advice based on your specific needs.
Yes, all members of our Nerve-Senor family can be glued onto or installed next to a pipeline, thereby measuring strain, displacement, temperature, or acoustics. It is worth noting that our 3DSensor can measure pipeline performance without the need to connect it to the pipeline by gluing. It is enough to place the sensor on the pipe and stabilise pointwise.
This can be done under the right conditions, but requires training and necessary equipment. It is therefore preferable to send you pre-cut sections. If splicing is required on site, we can work with you on an individual basis. See also: Can we spice the pigtails on our own?
The length of the pigtails is decided individually with the customer. Typical lengths (already included in the price of the sensor) range from 1 to 15 m.
The monolithic core of our strain sensors is one of Nerve-Sensors’ greatest advantages. Extracting the fibre from the core, splicing and applying the right mechanical protection requires specific know-how. However, after signing an NDA agreement and placing an order, we can arrange paid training for your team on how to splice our sensors.
Yes, we can do the installation ourselves, but we can also assist you with the design or supervise the installation on site.
You will need to use appropriate protection elements and relevant epoxy. You can find out more details on our training courses.
We always treat each installation individually, selecting sensors best suited for a given environment. However, all sensors whether fibre optic or traditional can be damaged on busy construction sites. In those cases, on-site splicing is challenging but possible if we have physical access to the sensor where the damage occurred. Same goes for our clients who have been trained in splicing. See also: Can we spice the pigtails on our own? In some projects where sensors are connected in a series, it would be possible to replace the entire segment.
Once installed (integrated) into the structure, the sensors themselves do not require any maintenance or calibration. However, depending on the installation, certain inspections may be required (e.g. visual assessment of adhesive quality, cleaning the connectors like in standard telecom applications, etc.).
Usually, the installation is the riskiest stage. Once the sensors are installed, in most cases they should be safe from damage. If needed, for more extreme applications, we can adjust the physical resistance of the sensors by selecting appropriate diameter, core material and maximum strain range.
On-site splicing is challenging but possible if we have physical access to the sensor within the break. Repair options depend on the type of structure and installation method, and should always be individually analysed prior to installation.
Yes. Our family of Nerve-Sensors was designed especially for civil and geotechnical applications. The composite material from which our monolithic sensors are made ensures resistance to corrosion. Depending on the selected sensor type, Nerve-Sensors can withstand high temperatures, mechanical pressures, alkaline concrete environment and changes in temperature or humidity. It is recommended that sensors are protected from direct UV radiation.
We expect the durability of our sensors to be no worse than the predicted lifetime of the structure being monitored itself (measured in decades). Our first installations were made in 2017 and there is no sign of deterioration to date.
Yes. We have performed tests in our laboratory where sensors were immersed in 5% NaOH (sodium hydroxide) for 8 months and there were no signs of deterioration after that time.
Yes, measurements are based on optical signal not susceptible to interference from electromagnetic waves.
Please send us an email to: contact@nerve-sensors.com. One of our engineers or technicians will contact you directly thereafter.
Yes, we do. We offer a measurement service using one of our interrogators. In our laboratory we use Rayleigh, Brillouin and Raman instruments from various suppliers including Luna, Neubrex, FibrisTerre, Yokogawa, Febus and others.
Depending on the type of sensor, the applied interrogator and the installation method, we can continuously measure various physical quantities along the entire length of the sensor, including: strains [µε], cracks [mm], displacements (shape changes) [mm], strain rates [nε/s] or temperature [°C].
Our sensors can be connected in series to theoretically an infinite length. The maximum length therefore depends on the limitations of the interrogator used (including the optical budget). Today, optical paths of more than 100 km can be realistically achieved.
Yes, depending on the type of interrogator used. Distributed Acoustic Sensing (DAS) can even measure at 40 kHz frequency.
Yes it can. The data is then streamed to an online platform where it is processed and visualised in near real time (e.g. every 60 minutes). Please contact us for further details on the web based DFOS platform for data post-processing and visualisation.
It depends on the requirements of the project and measurement lengths. Usually one is enough, but there are applications where we use more, e.g. Rayleigh for strain and Raman for temperature. We can connect different interrogators to different fibres within the sensor itself to measure at the same time.
We need to use an optical interrogator for DFOS sensing. Despite the many suppliers on the market, there are three main types of devices: Rayleigh, Brillouin and Raman based. Each has its own advantages and limitations. The choice should be made on a case-by-case basis, taking into account the requirements of the project. You can always contact our team who will advise you on the best solution.
We can provide measurement service with or renting out one of the following interrogators:
- FEBUS (Rayleigh) for DAS
- FibrisTerre (Brillouin) for DSS, DTS and DDS
- LUNA ODiSI (Rayleigh) for DSS, DTS and DDS
- LUNA OBR (Rayleigh) for DSS, DTS and DDS
We use software and switches to automate measurements and multiply channels - LUNA HYPERION for FBG
- NEUBRESCOPE NBX (Rayleigh and Brillouin) for DSS, DTS and DDS
- YOKOGAWA (Raman) for DTS
Usually you need to provide stable temperature and humidity, without dust. The specifications of the device used should be studied carefully prior to installation.
It depends on the number of channels, sensor lengths, interrogator type, measurement settings (e.g. spatial resolution, number of averaging, etc.). Typically, a single static measurement lasts from a few seconds to a few minutes.
You can apply an additional optical switch or manually reconnect the sensors (for non-automatic measurements).
This depends on the requirements of the DFOS interrogator used. Usually, Rayleigh – based devices work from a single-ended sensor, while Brillouin has better parameters in a loop configuration (connection from both sides of the sensor). Since we have at least two fibres inside the sensor core, we can also make a small loop at the end of the sensor (in this case you can have both a straight section and a loop configuration at the same time).
Each DFOS interrogator has its own raw data format. If we are assisting you directly, we usually provide exported data in TXT or CSV format. The data columns represent the subsequent measurements over time, while the rows provide strain, displacement or temperature profiles over length.
There are different options for DFOS data visualisation. Typically, we present the following plots:
- strain profiles in length domain in subsequent measurement steps
- strain profiles in time domain at selected locations over length
- spatial visualisation of strain profiles both in time and length domain
Yes we can, for example for thermal compensation, crack width estimation or displacement (shape) calculation.
You need to know the temperature change (ΔT) over length and the thermal response of the sensor, which in our case is linear. The thermal coefficient for strain sensors is 10.1 µε/°C. The temperature change ΔT can be measured using a DFOS approach or conventional spot thermistors. We can advise you on the best solution for your specific application.
You will need to integrate the strain profiles within the crack area, assuming the effective lengths and boundary conditions (different for reinforced and prestressed concrete structures). The analysis should be done after thermal compensation of the strain sensor itself. You can find more information in this article: https://doi.org/10.3390/s23020566.
We are also available to assist you with this service.
Our tests show that there are no technical differences in the results obtained with spatial resolutions from 1 to 20 mm. Therefore, there is no reason to increase the number of data points and the size of the measurement files. Normally we recommend 10 mm spatial resolution for crack analysis in concrete.
You can indeed take this approach. For visual assessment, you can simply present these data on the same plot (with synchronised lengths). However, if you want to do specific calculations (e.g. apply thermal compensation), you will need to do some additional mathematical post-processing, including resampling the data sets to have the same number of points over length. A local approximation approach can be used for this purpose.
The algorithm is based on the measured strain profiles in 4 fibres inside the 3DSensor core, known spacings between the fibres and assumed boundary conditions (e.g. simply supported beam or cantilever scheme).
The most important thing to remember is that displacement calculations are based on the measured strain profiles. The true deformation must therefore be large enough to be measured by the interrogator. The accuracy and spatial resolution of the instrument is also important. For example, we will not be able to measure 10 mm of displacement over a 100 m section because the true strains in the fibres will be much less than 1 µε.
Yes, there is. Please contact our team for further details.
We can provide you with some algorithms for your own post-processing in Excel, Matlab or Python. A cloud-based online platform for automated measurements is also available. Please contact our team for more details.
Sure thing. Our team consists of specialists in civil engineering, materials science, mechanics and optics. We can support you in applying algorithms to obtain data in engineering units, but we can also provide advice on how to interpret them in relation to the technical condition of the structure being monitored.
Definitely. During the training we can discuss hundreds of laboratory and in situ results from our DFOS projects.
This depends on the size of the order and the length of the sensors. Typically we use rigid boxes for smaller packages and wooden pallets for larger ones.
Yes, aside from Europe we have shipped to many countries including USA, Australia, Japan, Taiwan, Mexico, Brazil, RPA and many more.
Standard preparation time is no more than 3 weeks for strain sensors and 4 weeks for displacement sensors (excluding shipping time). We do our best to shorten the delivery time, taking into account the current load on the production hall.
Yes, they are.