Distributed Sensing Systems for Leak Detection

The increasing role of the oil and gas industry has led to development of many related technologies including distributed sensing systems. Among other things, they have become a part of the leak detection technology that has proved to be one of the most powerful.

For development of the most cost-effective detection technology there should be a balance between three elements: well-trained staff, properly configured distributed monitoring systems and proper operations’ arrangement. By observing these conditions, the effective operation is achieved.

With distributed monitoring systems, the pipeline management leads to the fast detection of any accidents, thus, reducing the extent of damage, as well as unforeseen expenses.Distributed Sensing Systems for Leak Detection

The Most Common Classification of Distributed Sensing Systems

Distributed sensing is a continuous monitoring technique which operates across the whole fiber optic cable in real time.

In contrast with the conventional sensors that were previously applied, distributed sensing systems use the whole optical fiber instead of the separate sensors that measure parameters in certain points. For this reason, fiber optic systems are easier to install even in heavy ambient conditions. With fiber optic cable, specialists have no need in defining particular locations where sensors should be placed. This fact makes the monitoring process more cost-effective.

The distributed sensing systems are different due to the data they require. So, there are distributed acoustic sensing (DAS) or distributed temperature sensing (DTS).

  • Distributed temperature sensing (DTS) uses a fiber optic cable that serves as linear temperature sensors. Eventually, specialists get the full temperature profile for the required period.
  • Operation principle of the distributed acoustic sensing (DAS) is similar to the DTS system. It applies a fiber optic cable as well, that provides the data. However, instead of registering temperature changes, they are relying on the acoustic and vibration changes in fibers.

Applications of the Leak Detection Systems

Leak detection fiber optic systems are installed to get the information about any appearing changes in parameters and leak possibilities. The distributed monitoring systems are able to find leaks almost instantly.

Here are a few examples where fiber optic sensing systems have found their applications:

  • One of the last well-known developments connected to fiber optic sensors is the monitoring of offshore Arctic fields. Pipelines are constructed for safe transportation of oil and gas avoiding any leaks. However, there are high risks of their deformation because of the severe environmental conditions like the effects of ice gouging, permafrost thaw settlement, or physical damage. The absence of fiber optic monitoring systems may result in severe environmental, and economic impacts.
  • Distributed sensing systems can be also applied for liquid sodium leaks monitoring. Fiber optic sensors can be implemented into various nuclear power plants and other facilities. Electromagnetic immunity, ability to resist high temperatures and operating in radioactive environments make fiber Bragg grating sensors a powerful instrument in monitoring.
  • Distributed monitoring systems are also used at wastewater treatment plants. The leak can lead to dangerous consequences such as spillage of contaminated fluids and therefore environmental damage.

Main Purposes of the Fiber Optic Technology Applications in Leak Detection

Fiber optic sensing systems bring many benefits while using. As a result, they have become useful instruments and can be applied for different purposes. Firstly, distributed monitoring systems are usually used for monitoring any changes that take place over long distances of the pipelines. Fiber optic sensors can monitor flow rates, temperature, pressure, ground strain, etc. All measured physical parameters are sent to the center where all the data is displayed with the help of the software.

Due to the received data from fiber optic monitoring systems, specialists are able to watch any changes or conduct the necessary calculations. In case of any changes, the operator or security personnel gets a signal that there are changes and sees their accurate site. So specialists can quickly respond to any changes and prevent any further possible damage.

The other purpose of distributed sensing monitoring is leak detection. Fiber optic monitoring systems can be installed both on buried and unburied pipelines. They can detect the precise location of the leakage in a short time. Moreover, they can discover other accidents like ground disturbances, theft, manual and machine excavation, etc.

Fiber optic monitoring systems designed for the oil and gas industry can also help in optimizing the lifetime of the wells. They are used as integrity monitoring instruments of the storage tanks, process vessels and other equipment. Considering all the information, specialists can make a decision on the maintenance programs as a means of extending the service life.

Due to all these possible applications, distributed sensing systems have found their place in the gas and oil industry. Fiber optic sensing systems have proved to be cost-effective in measurements of main parameters in pipes in the conditions of severe environmental and industrial equipment.

Optromix is a fast-growing vendor of fiber Bragg grating (FBG) product line such as fiber Bragg grating sensors, for example, FBG strain sensors, FBG interrogators and multiplexers, Distributed Acoustic Sensing (DAS) systems, Distributed Temperature Sensing (DTS) systems. The company creates and supplies a broad variety of fiber optic solutions for monitoring worldwide. If you are interested in structural health monitoring systems and want to learn more, please contact us at info@optromix.com

Distributed Sensing for Seismic Monitoring Systems

We have already published a range of articles referring to different applications of fiber optic technology in various industries and fields. Geophysics has also applied distributed sensing as a powerful instrument for structural health monitoring, such in, the oil and gas industry, tunnel safety monitoring, etc.

Seismic monitoring has been no exception. Resistance to electromagnetic disturbance, cost-effectiveness and possibility of implementing into hard-to-reach regions or places that can be harmful for human health are undeniable advantages of distributed sensing systems.Distributed Sensing for Seismic Monitoring Systems

What is Distributed Sensing Technology?

Distributed sensing is a technology that provides continuous measurements in real-time. Compared to traditional sensors, placed at certain points, distributed sensing acts as a sensing element along its entire length because the whole fiber optic cable is applied.

Due to the exploitation of the entire fiber optic cable all over its length, this method is considered to be one of the most cost-effective tools that can be placed in severe conditions.

Operation Principle of the Distributed Sensing Systems

In simpler terms, DAS systems as a part of the distributed sensing technology consist of several components including fiber optic cable and an attached optoelectronic device – FBG interrogator. The interrogator sends short pulses of the pulsed laser light into fiber optic cable. Then the backscattered light moves back up the fiber to the FBG interrogation unit. Due to the time that the laser pulse takes, there can be found the relation backscatter event and a fiber distance.

The FBG interrogator is connected to a processing unit that processes and stores the received data. This unit gets the raw data and transfers it into the information that is displayed in the program.

The software provides the visualized analysis that includes the previous data as well. In case there are any differences, fiber optic system alarms specialists. For instance, the system can display the location of the fiber optic cable on the map and highlight locations where the rates have changed or exceeded acceptable limits.

What’s the Difference Between DAS and DTS Systems?

Traditionally, distributed sensing systems are divided into distributed temperature sensing and distributed acoustic sensing.

The main difference between DTS and DAS systems is the type of signals they get to provide analysis. DTS systems are sensitive to temperature changes, while DAS is sensitive to acoustic vibrations. Therefore, their operation principle is also different. Due to the fiber qualities, the performance of DTS systems is able to stay at the necessary high injected pump power level. At the same time, DAS systems don’t require such high pump power as DTS systems because of the Rayleigh scattering.

DAS Systems and Their Applications in Seismic Monitoring

If we are talking about seismic monitoring, distributed acoustic sensing is used. DAS systems measure any vibrations that can’t be detected by DTS technology.

The goal of all seismic monitoring systems is warning before any accident occurs. Their effectiveness depends on the accuracy of the obtained data, lifetime and length. That’s why there is a necessity in a continuous operating system that is capable of working in severe environments and over long distances.

DAS systems were implemented as seismic monitoring systems due to the above-mentioned advantages as well as low cost, no special maintenance, robustness, etc. Therefore, distributed acoustic systems have provided new capabilities for seismic monitoring.

Field Projects Where Sensing Systems Were Applied

If we are talking about sensing systems, in most cases fiber optic sensors were more effective in comparison with the conventional electronic ones. That provides unrivaled performance, especially in critical applications.

For example, two years ago the specialists started a range of experiments in the Arctic and the Arctic Ocean. This is the first case when DAS systems were installed in the Arctic. Scientists wanted to get the analysis of the seafloor seismic activities and other processes under Arctic sea ice with a distributed acoustic sensing system. Fiber optic cable catches the vibrations about all the changes of the ocean 24/7.

The other project with DAS systems has also allowed scientists to see them in other severe environmental conditions. Since they are installed mostly in the ground, specialists have monitored their performance in snow. The most concerning parameters for them were the snow depth and severe frosts.

Finally, in the conditions of decreasing temperatures the reduction in background noise and better signal-to-noise ratio was noticed. In fact, the lower temperatures, the better results distributed acoustic sensing has provided. Cold temperatures don’t make fiber optic performance difficult or interfere with accuracy of the received data. Moreover, fiber optic cable is able to transfer signals at snow depths of at least 0.65m.

Distributed sensing as a tool for seismic monitoring systems has proved to be effective in detection of any seismic shocks and flow changes. All in all, DAS provides capabilities for seismic monitoring of the near surface.

Optromix is a fast-growing vendor of fiber Bragg grating (FBG) product line such as fiber Bragg grating sensors, for example, FBG strain sensors, FBG interrogators and multiplexers, Distributed Acoustic Sensing (DAS) systems, Distributed Temperature Sensing (DTS) systems. The company creates and supplies a broad variety of fiber optic solutions for monitoring worldwide. If you are interested in structural health monitoring systems and want to learn more, please contact us at info@optromix.com

Fiber Optic Technology in earthquake monitoring

The improvement of life quality is the main factor in the development of every new technology including fiber optic technology. Scientists from all over the world have always looked for new solutions for the prevention of seismic events, which is one of the most essential points in life quality improvement.

Seismic data of the previous years, electric sensors, fiber Bragg grating sensors, and modern distributed acoustic sensing have an aim to predict all catastrophes connected to earthquakes in the future. Especially, it concerns areas with high rates of population. More accurate monitoring gives an opportunity to reduce the risks resulting from most common natural events like earthquakes, landslides, eruptions, etc.

Fiber Optic Technology in earthquake monitoring

 

FBG sensors in the prediction of seismic events

In the past, the only approach to all the natural phenomena was the information about the cases. Then electric sensors were applied. However, usual electric sensors are hard to comply with the monitoring requirements of high sensitivity and long lifetime. That is why scientists have tried to use different FBG sensors. In fact, fiber Bragg grating temperature sensors were produced for better monitoring and observation of seismic activity. Except for fiber Bragg grating temperature sensors, there are FBG strain sensors that can be also applied for collecting data as geothermal monitoring.

In comparison with the usual electric sensors, FBG sensors can offer ease in signal transmission and immunity to electromagnetic interference that plays an important role. In fact, temperature monitoring with the help of the FBG is considered to be one of the most popular applications. Moreover, modern sensors can be sensitive to both strain and temperature.

Distributed Acoustic Sensing in earthquake prediction

If we speak of seismic activity and the prediction of seismic events, we should definitely mention another fiber optic technology that helps in geothermal monitoring called distributed acoustic sensing. DAS systems are widely applied in various spheres, including vibroacoustic monitoring of the oil wells.

Scientists have already held a number of experiments with the help of the distributed acoustic sensing studying seismic activity in different areas such as metropolitan, oceans, etc. The results prove that DAS systems are able to accurately detect vibrations even in conditions of a highly noisy environment and far away from the epicenter. That’s why this fiber optic technology draws the attention of many researchers and is popular where there is a need for precise and robust information. The DAS’s improved performance has shown its potential to be a powerful instrument in geophysics studies thanks to its bandwidth, waveform fidelity, cost-effectiveness, and simplicity.

Despite all the achievements in fiber optic technology, scientists still consider that DAS technology for seismic monitoring is still in its infancy. However, they are sure that such promising opportunities will play a crucial role in the next seismic networks.

Optromix is a DAS system manufacturer that provides top-of-the-line distributed acoustic sensing systems suitable for monitoring commerce networks. If you have any questions or would like to buy a DAS system, please contact us at info@optromix.com

Fiber Optic Technology for the earthquake warning

Fiber Optic Technology for earthquake warningA research team from the USA has applied FBG sensors for detecting earthquakes and creating a system for subsurface imaging with the help of fiber optic technology. The sensors were installed above an existing fiber optic cable.

According to scientists, this fiber optic system can register seismic signals produced by trains and automobiles. These signals cause changes in the fiber optics’ length from the very beginning till the very end. This fiber optic system is also known as distributed acoustic sensing or DAS.

Scientists have also installed usual high-resolution seismometers along the fiber optic cable in addition to the new DAS technology. They have aimed to compare these two methods of signal detection. In distributed acoustic sensing the fiber laser light is sent through the fiber optic cable. DAS technology measures the perturbations in the backscattered light along the whole fiber optic cable.

In fact, scientists made a conclusion that the fiber optic system is sensitive enough to detect footsteps. The other research team from one of the US universities proved that fiber optic technology can provide data about street traffic and demonstrated the results of the lockdown 2020. The fiber optic system could locate vibrations from cars and pedestrians above and demonstrated that the pedestrian traffic almost disappeared in April and stayed almost the same in June.

However, according to this scientific research, the fiber optic cable can even detect the jet airplanes that fly by. The scientific work was much easier because DAS systems are easy-to-install devices in comparison with the traditional methods. Scientists just needed to use a single fiber optic cable instead of thousands of geophones to detect ground vibration. Researchers got the same information using fiber optic technology faster. The DAS system continuously monitors the modifications in the fiber optics’ length down to changes in the length of less than 1 nanometer.

Thanks to the DAS technology the research team will calculate the velocity structure in the subsurface by measuring the strain changes. The velocity is a crucial factor in the determination of how the ground and civil infrastructure may respond to an earthquake.

Thanks to the new fiber optic technology, scientists and engineers are going to improve velocity and ground motion models in urban areas by collecting more information. Moreover, they hope to find a better understanding of the seismic risks and assess the resilience of our infrastructure.

Besides, the research team has a plan to spread this fiber optic technology for a vast territory to develop a better early-warning system for earthquakes. This is a totally new way of thinking about monitoring and designing for earthquakes that can give people time to get to shelter.

Optromix is a DAS system manufacturer that provides top-of-the-line distributed acoustic sensing systems suitable for monitoring commerce networks. If you have any questions or would like to buy a DAS system, please contact us at info@optromix.com

Fiber Optic Technology in humans movement tracking

Fiber Optic Technology in humans movement trackingA team of researchers from the US university applied fiber optic technology to demonstrate the changes in city traffic because of the lockdown. Scientists had tapped into an underground telecommunication fiber optic cable and made a scientific monitoring device. Thanks to this fiber optic system, they could watch how Covid-19 brought life to a halt.

According to researchers, they shined a laser through the fiber optics and could locate vibrations from cars and pedestrians above. The fiber optic cable could detect the movement through the unique seismic signals from them. That allowed scientists to create a detailed picture of how a community ground to a halt, and then slowly came back to life when the lockdown eased.

This experiment with the fiber optic cable showed that the pedestrian traffic almost disappeared in April and stayed almost the same in June. However, the car traffic started increasing after initially declining. As a result, the vehicle traffic is actually back to normal, while people walking is still minimal. Moreover, scientists could distinguish the vibration signals from fiber optic cable from construction vehicles. In April there was no industrial activity as the construction halted. But in June the construction vehicles’ movement had started again.

Fiber optic cables trap light pulses and transport them to vast distances as signals. And when a car or person passes, the vibrations introduce a disturbance, and a scattering light returns. The researchers measured vibrations at different lengths of the fiber optic cable by estimating the time it took the back-scattered light to travel. This method is well-known as distributed acoustic sensing (DAS).

Distributed acoustic sensing (DAS) can become an instrument for tracking people’s movement instead of cell phone location data studying. Researchers can apply fiber optic cables to monitor pedestrians and cars. However, DAS can’t help in identifying a particular car or person. It can only identify a type of vehicle, for example, truck or bike.

In comparison with usual seismometers, such fiber optic cable is cost-effective and doesn’t need a source of power. There is a need for just an FBG interrogator that gets the information.

Engineers have already produced DAS systems to detect soil deformation, biologists use offshore fiber optic cables to listen in on whales, and scientists made measurements of earthquakes and water temperature in the Arctic with the help of FBG sensors. Every day fiber optic technology gets a new application.

Optromix is a DAS system manufacturer that provides top-of-the-line distributed acoustic sensing systems suitable for monitoring commerce networks. If you have any questions or would like to buy a DAS system, please contact us at info@optromix.com

Fiber Optic Technology and its recent advances

Fiber Optic Technology advancesDuring the last 60 years, fiber optic technology has been applied to improve the efficiency of developed systems in various spheres like medicine, vehicles, and other industries. Modern fiber optic solutions expand the abilities by implementing levels of data and sensing technology in the energy, medical field, and even aerospace. There are various fiber optic solutions that help researchers improve their development and make new discoveries in science.

Intrinsic and extrinsic fiber optic sensors are two wide categories of fiber optic sensors. Extrinsic fiber optic sensors utilize the fiber to manage the light to a sensing region. Then the optical signal is modulated in another environment. Talking about the intrinsic fiber optic sensors, the light remains within the waveguide. So it measures the influence of the optical fiber signal.

Intrinsic fiber optic sensor technology, where the fiber optic sensor is the fiber optic cable itself, has improved significantly during recent years. There are two main technologies connected to intrinsic fiber optic sensors: scattering and FBG. FBG methods can be fully distributed or have many sensing points. With the help of FBG sensors, scientists can define the changes by getting precise measurements. Scattering techniques depend on natural imperfections occurring in the fiber optic cable. The FBGs have a high signal-to-noise ratio in comparison with scattering techniques.

Both scattering and FBGs use different demodulation techniques. Scattering techniques get the information by observing changes in naturally back-scattering patterns. For FBG based technology, wavelength division multiplexing is the most prevalent demodulation technique. However, in certain circumstances, optical frequency domain reflectometry can become the most useful method.

Wavelength division multiplexing is able to spread to large distances and get the data rapidly. This technology can also support multiple fiber Bragg gratings on a fiber. It observes critical points more than the whole field of the data. That is why it is mostly applied in automobile crash testing as a monitoring instrument.

The scattering techniques can cover long distances and give a distributed profile of the data. They obtain information all over the entire fiber optic cable. Many systems on the market measure temperature or acoustics and are called Distributed Temperature Sensing (DTS) or Distributed Acoustic Sensing (DAS). These techniques are usually applied in monitoring a pipeline for tampering, for example, where there is no need for high-speed acquisition.

Optical frequency domain reflectometry is another demodulation technique that is mostly applied with FBG sensors where fiber Bragg gratings are placed really close and create a fully distributed sensing fiber. It has many advantages like the combination of high spatial resolution, a bunch of fiber optic sensors, a quick refresh rate, and a full distribution set. Apart from distributed sensing of a strain and temperature, this technology allows defining 2D deflection, liquid level, magnetic fields, etc.

Nowadays, thanks to fiber optic technology, scientists have an opportunity to solve any problems in their designs by using fiber optic systems. And there are still many possibilities for fiber optic technology in the future.

Optromix is a fast-growing vendor of fiber Bragg grating (FBG) product line such as fiber Bragg grating sensors, for example, fbg strain sensors, FBG interrogators and multiplexers, Distributed Acoustic Sensing (DAS) systems, Distributed Temperature Sensing (DTS) systems. The company creates and supplies a broad variety of fiber optic solutions for monitoring worldwide. If you are interested in structural health monitoring systems and want to learn more, please contact us at info@optromix.com

Distributed acoustic sensors (DAS) are applied underwater

DAS are applied underwater Scientists are looking for new ways of employment for distributed acoustic sensors (DAS). The fiber optic system contains a mandrel with a wounded with sensitized optical fiber. It is the acoustic sensor for a heterodyne that is protected for underwater use.

Nowadays, the DAS system can be used both for military purposes as well as for peaceful life. In the military, they are mostly utilized for submarine locations. While they are also in active use for monitoring sea animals’ life or finding and exploring marine mineral sources. The fiber optic systems based on the DAS technology have more advantages over the other items. First of all, they are thin and reliable. Secondly, there are no underwater electrical devices. And finally, the systems with acoustic sensors are immune to electromagnetic interference.

These devices usually contain an array of DAS sensors along with the fiber. Herewith, the arrays are up to a hundred or even fewer acoustic sensors because of the technical restrictions. The spacing between these acoustic sensors is fixed. That’s why there are some limitations in marine acoustic detection, for example.

The recent researches from China exploited a distributed acoustic sensing based on heterodyne coherent detection and demonstrated its field-testing. The optical cable contains a supporting mandrel, special optical fiber, and cable sheath. Acoustic signals from the fiber optic system disturb the mandrel and the fiber. That all causes phase changes which are the desired signal. The whole model was created to analyze the equivalence and specific character of the acoustic wave response.

With the array signal processing, the DAS device can easily find underwater acoustic signal sources and track motion trajectories. Moreover, the results of the experiments are highly accurate.

There are also obvious benefits of distributed acoustic sensors (DAS) in various industries. Most of which are elements of longer-term goals.

Some of the potential advantages of a distributed acoustic sensing are numbered below:

  • a low-cost acquisition system;
  •  a simple design;
  • no electrical energy required in the fiber optic cable;
  • the fiber optic cable is suitable for harsh environments (dust, temperature, harmful gases);
  • the fiber optic cable is immune to the radiations such as EMI (Electromagnetic Induction) & ESD (Electrostatic Discharge);
  • the fiber optic system can transform several kilometers long sensor that enables it to monitor on a truly distributed basis.

According to the researchers, the production of fiber optic systems based on the DAS technology can be easily automated. However, there is still a space for developing and finding new ways of optimization.

Optromix is a DAS system manufacturer that provides top of the line distributed acoustic sensing systems suitable for monitoring commerce networks. If you have any questions or would like to buy a DAS system, please contact us at info@optromix.com

What you should know about fiber Bragg gratings

fiber Bragg gratings (FBGs)Fiber Bragg gratings are currently widely used in optical fibers and light guides for compaction of channels along the wavelength, optical filtering of signals, as resonator mirrors in fiber and semiconductor laser systems, as smoothing filters in optical amplifiers, to compensate for dispersion in the main communication channels.

Another field of application of FBG technology includes its use in various measuring systems that control environmental parameters, such as temperature, humidity, pressure, deformation, and chemical content. Bragg gratings distributed along the length of the light guides allow for creating distributed acoustic systems that differ favorably from traditional complexes of the same purpose in cost and technology of production.

FBG technology for recording Bragg gratings distributed in a light guide is a key element in creating a new generation of measurement systems. Hydroacoustic antennas developed on the basis of such optical fibers, as well as systems for the protection of extended objects and systems for monitoring the condition of main pipelines, are increasingly being used abroad. 

A distinctive feature of these fiber optic systems is the large extent of controlled zones, speed, and unique information capabilities. When fiber Bragg gratings are written at a standard optical fiber, a problem arises because of the fact that such a fiber has weak photosensitivity and a low saturation threshold, which is not sufficient for effective recording of gratings. 

The main solution method of FBGs is to increase the concentration of germanium dioxide in the core. Other methods consist of alloying the pieces for the creating of optical fibers with such chemical elements as boron, tin, nitrogen, phosphorus, antimony together with germanium, which leads to an increase in the photorefractive power of the light guides.

Writing of fiber Bragg gratings can be classified by the type of laser system used for production, the wavelength of beam emission, the recording technique, the irradiated material, and the type of Bragg grating. Lasers used for FBG writing can be either continuous or pulsed, with a wavelength of emission from the infrared (IR) to the ultraviolet (UV) range of the spectrum. 

These differences determine the spatial and temporal coherence of the optical emission sources used for writing, which, in turn, determines the choice of the appropriate method for recording fiber Bragg gratings. The main methods for FBG writing include the step-by-step method, the phase mask method, and the interferometric method.

The need to increase the speed of information transmission, associated with the development of telecommunications, increasing information flows, the growth of global information systems and databases, the expansion of the number of users, led to the fact that fiber optic system communication lines were developed using spectral multiplexing of optical channels.

Optromix is a fast-growing vendor of fiber Bragg grating (FBG) product line such as fiber Bragg grating sensors, FBG interrogators and multiplexers, Distributed Acoustic Sensing (DAS) systems, Distributed Temperature Sensing (DTS) systems. The company creates and supplies a broad variety of fiber optic solutions for monitoring worldwide. If you are interested in structural health monitoring systems and want to learn more, please contact us at info@optromix.com

Distributed fiber optic sensors and their prospects

distributed fiber optic sensorsModern industrial systems are subject to increasingly strict requirements. Structural health monitoring must always work reliably regardless of environmental conditions. Observability and manageability become an important parameter. The operator must be able to detect a problem, including a potential one, determine the location of its occurrence, and respond in a timely manner, taking the necessary measures to reduce time and material costs in emergency situations.

Current fiber optic sensing technologies make it possible to continuously, accurately and in real-time detect small changes in temperature, acoustic background, and deformations in any place of an industrial facility. Fiber optic cables, which are traditionally used in the telecom industry for transmitting information, come to the rescue to perform this. Depending on the type of devices connected to the optical cable, it is possible to detect various environmental events at a long distance (up to several tens of kilometers) performing structural health monitoring. The sensitive medium is the optical fiber and a huge number of “virtual” sensors inside it.

DAS (Distributed Acoustic Sensing) are “virtual” microphones installed along with the optical fiber. Standard single-mode optical fiber and Rayleigh scattering are used when acoustic vibrations cause small changes in the refractive index that are detected using this scattering. The fiber literally “hears” events occurring in the environment. The number of DAS is a combination of spatial resolution, distance, and pulse duration. Modern distributed fiber optic sensors can operate at distances of up to 80 km. Combining several devices into a single network allows for creating thousands of kilometers of structural health monitoring lines.

DTS (Distributed Temperature Sensing) is “virtual” thermometers along with the optical fiber. The distance range for a conventional single-mode fiber is up to 100 km with a spatial resolution of 1 to 5 meters and a measurement accuracy of less than 1 degree Celsius, with a measurement time of 2 to 30 minutes. These parameters are interdependent. For example, the longer the measurement time is, the better the spatial resolution and accuracy of the measurement are, and vice versa. 

Herewith, analytics show that the market for such distributed fiber optic sensors will grow by at least 10% per year in the foreseeable future. These fiber optic systems are most in-demand in North America. In terms of application, the oil and gas industry has the greatest potential. Temperature control prevails by type of monitoring.

Over the past 10 years, fiber optic sensing technology has been used to monitor thousands of kilometers of pipelines, thousands of oil and gas wells, and more. There are numerous fiber optic solutions that allow accelerating the introduction of promising technology in the industry, devices, and fiber optic cables are constantly being improved and become more accurate and affordable.

Optromix is a fast-growing vendor of fiber Bragg grating (FBG) product line such as fiber Bragg grating sensors, FBG interrogators and multiplexers, Distributed Acoustic Sensing (DAS) systems, Distributed Temperature Sensing (DTS) systems. The company creates and supplies a broad variety of fiber optic solutions for monitoring worldwide. If you are interested in structural health monitoring systems and want to learn more, please contact us at info@optromix.com