Category: Distributed Temperature Sensing (DTS)

Structural Health Monitoring Systems Applications

Structural health monitoring systems have found a number of applications in various fields. A complex approach including several techniques is the best solution for detecting damage and structural changes.

Here are some examples of its implementation in structures where fiber optic technology is more commonly used. Structural Health Monitoring Systems Applications

Structural Health Monitoring Common Information

The most effective methods of maintenance programs include early detection of material degradation and failure. Mostly, fiber optic systems have two purposes of applications:

Structural efficiency control during the construction;
Continuous monitoring of structural efficiency under service loads.

Structural health monitoring systems consist of three subsystems:

A network of fiber Bragg grating sensors;
An FBG interrogator that records the optical reflection from each fiber optic sensor. They are placed in the necessary locations, depending on the applications and type of the structure.
A processing unit that collects all the data from the FBG interrogator, processes it and transmits it to the user.

Distributed Sensing Systems

Distributed temperature systems are often the choice for harsh environments where traditional sensors may not be suitable. When we talk about dams, tunnels and similar structures, there are conditions that greatly affect the operation of the structures and sensors. Ground movement, earth pressure, water and groundwater have an impact on the reliability and efficiency of any monitoring system.

Specialists can monitor all deformations and temperature changes through distributed sensing. Distributed fiber optic sensors are capable of measuring various parameters from thousands of points and transmitting them to a center that provides complex data on any changes.

Distributed temperature systems are often the choice for harsh environments where traditional sensors may not be suitable. In the case of dams, tunnels and similar structures, there are conditions that have a major impact on the operation of the facility and its sensors. Ground movement, earth pressure, water and groundwater will affect the reliability and efficiency of any monitoring system.

Structural Health Monitoring of Dams

Dam safety can have a significant impact on the surrounding environment and people. That’s why structural health monitoring of the dams is an essential part of the dam safety regime. Timely detection of defects and minimizing the effects of possible damage are the main purposes of such systems. However, specialists may face some difficulties due to the height and complex structures of the dams. Comprehensive structural health monitoring can’t be fully achieved with just a few monitoring points; it requires a complete, properly designed fiber optic system. Another problem is that some areas of the dams are inaccessible or difficult to access.

There are a number of factors that can affect dam construction. These include temperature, hydrostatic pressure, chemical reactions, etc. There are also environmental factors such as air temperature, reservoir levels, and earthquakes.

All of these circumstances can be the cause of typical dam problems such as cracking, displacement, etc. The other problem is the appearance of internal erosion, which can cause the failure of the whole mechanism in the future. This problem is hard to detect. That’s why it is important to have an effective fiber optic system in place for structural health monitoring and therefore safe operation.

Accidents in dams usually occur during the first filling or in the first few years of operation. However, there are also accidents that occur later.

Structural Health Monitoring (SHM) of Tunnels

SHM is able to provide a quick assessment of the state of health of the tunnel. It is typically used for safety improvement and optimization of maintenance and operations activities. The fiber optic monitoring system provides data on any changes in indicators that could be the cause of tunnel collapse. This makes it possible to monitor the stability of the structure and take action when it’s needed.

The construction of tunnels is based on soil conditions, the functions of the tunnels themselves, and logistical issues. Underground construction is irreplaceable, especially in cities where land resources are scarce. They are not as susceptible to the effects of natural disasters as are structures on the surface of the earth.

In the hard-to-reach or problematic areas of the tunnels, distributed monitoring systems are usually recommended. This makes it easy for staff to monitor the condition of their structures and perform necessary maintenance in a timely manner. This is especially important when it comes to fires – the biggest danger in tunnels. There are special fiber optic systems for temperature control and early warning of ignition, including fiber optic heat detectors.

Today, there are automated fiber optic solutions that provide accurate monitoring from a remote location. These fiber optic devices are often designed specifically for use in critical locations. In addition, they consider the cases that may occur, such as the use of the additional FBG sensors. If the other sensor fails, they will be able to operate.

Distributed temperature sensing is a newly introduced technique capable of complex structural health monitoring systems. Temperature and pressure control is especially important for dams and tunnels with their difficult-to-access locations and other challenges that staff usually face. SHM is the solution for these situations.

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 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.

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Distributed Temperature Sensing Systems for Coal Mines

Distributed temperature sensing systems as well as fiber Bragg optic sensors are focused on the continuous monitoring of the constructions’ health condition and prevention of potential damages. The DTS system consists of a fiber optic cable, typically several kilometers long, that works as a temperature sensor. As a result, specialists can watch all dynamic temperature changes in a continuous temperature profile. DTS Systems for Coal Mines

DTS Systems as a Fire Detection Technology

In the mining industry, the risk of fires still remains very high. Conventional fire and heat alarm systems require constant and expensive maintenance and are not as effective as fiber optic monitoring systems. Thanks to modern DTS technology, both of these problems are now solved.

There are many forces in mines that can cause a fire. The possibility of fire is especially high in certain locations due to the complicating factors such as:

geological settings;
presence of the vehicles, heat-generating and mobile equipment;
conveyor failures;
lighting faults, etc.

Distributed temperature sensing systems have been proven to outperform standard fire detection systems in a range of aspects including efficiency and high level of safety.

The DTS system includes a single fiber optic cable and a DTS unit. The traditional system includes many components and devices. The distinction of DTS results in lower installation and maintenance costs due to less equipment, and in improved system reliability. Therefore, there is no need in its regular service that can be complicated because of the difficulty of access and huge size of the mine. Moreover, the conducted field projects have demonstrated that fiber optic sensors inform the operators about the heat significantly earlier than a fire starts.

All these advantages have made DTS technology one of the main methods for the detection of potential fires or other abnormal conditions.

Fiber Optic Sensors for Detection of Faulty Conveyor Belt Rollers

The conveyor belts are cost-effective instruments for continuous transporting of dry bulk materials over various distances. Due to the latest technologies, the accidents related to the problems with conveyor belts are relatively rare in modern underground coal mines. However, to this day there is a possibility of causing damage related to the conveyor belt accidents that can result in the interruption of the production process.

The reliability of the whole conveyor belt depends on the robustness of its separate components. Distributed temperature sensing (DTS) system helps to monitor the thermal conditions of each idler and detect the malfunctions. DTS systems use the latest advancements of fiber optic technology. They have proven to be a safe method of application in underground mines.

There are some aspects to consider when choosing the suitable monitoring system. Firstly, it is not easy to obtain data from a vast area. It requires the setting up of thousands of sensor elements. Secondly, the data transmission can be challenging due to the underground mine environment. Therefore, some types of equipment are prohibited for usage, such as electrical cables. Fiber optic monitoring systems have been able to solve a number of such issues that engineers usually face during underground mining.

The DTS system consists of a DTS unit and a fiber optic cable. The system measures temperature along the entire length of the cable and transmits the data to the operators who can detect any mechanical failures of the rolling components at an early stage. The specialists see real-time data of the conveyor structure and the surrounding area.

The specialists conducted a range of experiments to find the most effective placement of the fiber optic monitoring system. The problem is that fiber optic sensors can’t be located over the idlers because they will interrupt the operation. So they are attached to the frame of the idler, as close to the bearing as possible. This affects the results because fiber optic sensors take longer to capture the heat. However, they still have better results compared to the traditional methods.

Fiber Optic Sensing for Monitoring of Roof Activity

According to statistics, there are many causes that can lead to mine accidents including dust explosions, mine support deterioration, etc. However, the most common cause of the accidents that take place in underground coal mines is mine collapse.

Design and functioning of the underground mines creates a number of complicated factors for operation. The dynamism of mining operations and increasing depth can lead to the associated risks and jeopardize an acceptable level of safety. At the same time, there are always natural risks to the mine structures, such as seismic shocks which can also lead to roof stratum displacements.

Roof activity monitoring can be used for a variety of purposes, including structural health construction monitoring of the underground openings and design optimization. For the majority of projects, fiber optic monitoring systems are applied due to their ease of use in harsh environments compared to other conventional methods.

Fiber optic sensing monitoring is able to help in reduction of the mine roof displacement and thus avoid severe consequences. There are different types of fiber Bragg grating sensors that are used to monitor displacement, temperature or strain in underground openings or nearby them depending on the purposes. FBG sensors have proved to be reliable and accurate monitoring equipment of roof activities in underground coal mining. Modern fiber optic monitoring systems have made it possible to display all changes of the required parameters on the screen almost instantly and prevent any accidents in underground mines.

The conducted projects on the mining sites have demonstrated the benefits of fiber optic sensors. The fiber optic monitoring systems can detect the slight roof displacement during the progressive face advance. The received data is usually used for roadway support and design of the mine.

In conclusion, thanks to the latest state-of-the-art technologies nowadays there is an opportunity to monitor structural health constantly. That is why distributed temperature sensing systems are widely applied for structural health monitoring of different constructions including mines. The fiber optic sensing has found many spheres of applications due to the qualities it has.

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

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Dual Lasers in DTS Systems for Oil and Gas Wells

DTS systems provide the oil and gas and other industries with the new cutting-edge fiber optic solutions such as a groundbreaking dual laser technology which offers the most robust and the simplest distributed temperature sensing systems accessible to the industry. This technology also includes the ability of the automatic correction for dynamic changes to the sensing fiber.

What is Distributed Temperature Sensing?

Distributed temperature sensing, also known as DTS, is a technology that measures the temperature along the whole fiber optic cable in a continuous fashion. The fiber optic line can be any required length up to 30 km. The system includes the recording instrumentation at one or both ends of the cable. It can work permanently or from time to time for each use, depending on the requirements. Dual Lasers in Distributed Sensing Systems

Most Common DTS Applications

Distributed sensing systems have established themselves as an effective part of fiber optic technology. High temperatures are related to the severe environmental conditions which make operational processes difficult. However, fiber optic sensors can operate in such conditions greatly, especially, if we compare them with the electrical-based temperature sensors. That’s why fiber optic systems have found many applications, such as fire detection, healthcare, railways, etc.

DTS systems are installed on the electric power lines to monitor temperature changes. The temperature may indicate the electrical overload or other deviations from the norm in time. DTS technology allows power companies to exploit the assets more effectively.

With the help of constant monitoring, it is easy to react immediately to the temperature rising. When this rising is above a predefined threshold, the alarm sets off. The early detection and warning lead to reduction of the damage that failures may cause.

DTS Applications in the Oil and Gas Industry

Fiber optic technology has been used in the oil and gas industry for over the last 25 years. Fiber optic systems were installed in various types of oil wells starting from land wells and ending with offshore wells. Fiber optic technology allows watching down hole casing deformation or changes in sand screen completions.

Thanks to its operational principles, distributed temperature sensing offers critical asset monitoring solutions that can be applied for oil and gas companies. DTS systems immediately provide the actual and accurate information about temperature with high resolution and high speed. Fiber optic cable provides specialists with the numerous measurement readings along the whole optical fiber. This feature helps companies in detecting leaks along the pipelines, whether along its length or anywhere on the cross-section. The faster the leaks are found, the less damage can be. It means considerable cost savings for companies. Moreover, DTS technology helps in identifying under-performing zones, optimizing gas lift operations, etc.

Distributed temperature sensing has been applied safely to follow up pressure or reactor vessels. Depending on the required set-ups, the temperature measurements can be held as frequently as every 30 seconds. Any changes in temperature may point out some problems that have occurred. So the increasing temperature of the vessel wall usually predicts the system or the process failure.

Dual Lasers in DTS Systems

Each year, specialists implement DTS systems more often to make the efficiency of production better. The integration of the dual lasers into such systems is a new technology, aiming at the life extension of optical fibers and solving the most appearing concerns. The most common issues that optical fibers face are fiber darkening or their damage.

The fiber darkening can misrepresent the statements and lead to the failure of the DTS system. It occurs where there are high pressure and high temperature environments that are usual for oil wells. The darkening happens unevenly and is progressive over time that makes the manual calibration techniques ineffective. Moreover, different connectors on the fiber can result in various degrees of optical loss. Two lasers operate at different wavelengths, so there is an automated adjusting system for any changes in optical loss in the fiber. They immediately react and correct these effects which allows the further use without re-installation of the whole system from the very beginning.

Such fiber optic systems help in cost-reducing by avoiding the re-deployment of the equipment. Despite the other systems, they don’t need the manual calibration techniques, but operate automatically all over the length. The manual calibration usually requires repeated recalibration efforts.

Newly developed DTS systems with dual lasers offer great advantages especially where there is no or limited access to the optical fiber. They help to extend the lifetime of the fiber and ease fiber optic systems’ deployment.

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

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Distributed Temperature Sensing at shallow depths

Distributed temperature sensing (DTS) is a state-of-the-art tool that possess an ability to monitor temperature rates over large territory and across wide temporal scales. This fiber optic technology has proved to be effective in different spheres and industries. However, despite the long field experience story, it still has its limitations and challenges apart from all the advantages. For example, when we talk about its application at shallow or deep depths.

DTS at shallow depths

The main difficulties in Distributed Temperature Sensing application

Despite all the progress that was achieved during this decade, distributed temperature sensing still meets some challenges. For example, when applied to the ocean, since dynamic oceanographic processes have a wide range of parameters, ranging from various types of turbulence to different climates, all data obtained from DTS systems fully help in understanding the dynamics of a complex ocean. However, different constraints can make modifications in time scales creating restrictions. Furthermore, there is a need for many additional advanced equipment for broad spatial resolution. That’s why it’s still complicated to use DTS in oceanography. However, now there are cases when distributed temperature sensing (DTS) is applied, for instance, in the Atlantic.

Recently, the scientists announced the first experiments on the seafloor of the Arctic sea ice with the help of the distributed acoustic sensing (DAS) system. This research has shown that fiber optic technology is effective, despite all the difficulties the scientists have faced due to the harsh environment. The system recorded a range of events that commonly applied equipment couldn’t even detect. Moreover, the DAS technology has detected the icequakes, various climate signals, and marine life.

From the other side, DTS systems can be applied in measuring surface water temperature spatial variability in lakes and rivers. The received data helps in the assessment of different factors such as estimating fish habitat and thermal inertia, the interaction between surface water and groundwater, etc. Usually, distributed temperature sensing is successfully applied in rivers and lakes with sensitive and high-resolution temperature monitoring under the wide temporal and spatial scales. Nevertheless, difficulties may arise in streams with cobbly or bedrock-lined streambeds. To avoid all the challenges, more expensive additional technologies are needed.

There are other factors that should be ensured like sensitive equipment needs protection and continuous power to work. Besides, optical fibers are delicate, they shouldn’t be bent or crimped.

How the Distributed sensing system works

Distributed sensing systems are appealing because they are able to continuously sample preserving while maintaining relatively high temporal and spatial resolution. Moreover, the accuracy indicators stay the same over a vast territory.

Distributed temperature sensors measurement allows to constantly observe temperature changes along the fiber optic cable. In this fiber optic technology the whole cable plays the role of the sensing element that measures temperature. It differs this method from the usual electrical temperature measurement. Moreover, the distributed temperature sensing is regarded as the most cost-effective and efficient system among the modern temperature measurement technologies.

The main operation principles of measurement are built on detecting the back-scattering of light:

1. 1. 1. The first type is an optical fiber that uses Raman scattering. This approach was invented in the United Kingdom. Optical fibers are usually made from doped quartz glass. When the light falls on the excited molecular oscillations, the electrons of the molecule and the electrons of the molecule start interaction. This process is called Raman scattering and results in scattered light.
    2. The second method is the Brillouin scattering-based approach. It was mostly developed in the 1990s. It refers to the scattering of a light wave by an acoustic wave because of the interaction with the acoustic phonons. Thanks to the ability of the Brillouin scattering of making both frequency down- and up-shifted light, this method can be applied whether for distributed temperature or strain sensing. It can contain both, but they can’t work at the same time.
    3. The third technique is named Rayleigh back-scattering. This is the latest development. As well as for the previously developed distributed sensors, a usual optical fiber can be used as the sensor. It allows the entire cable to be used as a single sensor, without purchasing expensive individual sensors. Scientists applied this technique, for example, for measuring distributed temperature in a nuclear reactor.

If we compare all these three techniques, each of them has its pros and cons. According to the scientists, the Rayleigh scattering demonstrates the highest rates in comparison with other types. However, it has limits in a range of fiber length. This factor is crucial for long lengths of cables’ monitoring. For this characteristic, the Brillouin scattering shows the best results. Besides, it has temperature sensitivity and good measurement time. Moreover, Brillouin scattering allows to detect distributed strain, unlike the other two methods. But usually it is applied either for distributed temperature measurement or strain. According to the data, Brillouin scattering is more often used as a substitute for Raman scattering.

DTS systems in field experiments

In accordance with the final field experiments, despite all the challenges, temperature measurements with the help of the DTS systems have been performed successfully in various environments including rivers, lakes, seas, etc. The fiber Bragg grating sensors have been applied both in fresh and sea water and demonstrated good results. Furthermore, it refers to simultaneous measurement of temperature and depth which has been impossible for previous fiber sensors.

Modern fiber optic sensors provide the parallel measurements of temperature and pressure at the same place. Besides, in comparison with other methods, fiber optic technology provides much lower power consumption. It allows the DTS systems to work longer and makes longer experiments and observation possible.

The developed fiber optic technology can be used for measurements and monitoring of the physical parameters. Moreover, it is well-placed for many cases and can be applied to various applications, such as wave and tide gauges, tsunami warning systems, etc.

All in all, we can say that distributed temperature sensing (DTS) can be successfully applied in various cases at shallow depths due to their diversity. The system can be designed and installed in accordance with the existing conditions and parameters in every single case.

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Fiber Optic Sensing Systems for Oil and Gas Wells

Fiber optic sensing systems can greatly assist in the exploitation of oil and gas resources. During the downhole processing, technicians can face a variety of technical challenges resulting from difficult environmental conditions. Wellbore structural health monitoring is a substantial system that provides the profitability and reliability of these fields.

Fiber Bragg grating sensors have replaced traditional electronic sensors for reservoir monitoring and downhole production. In-well sensors are applied for measuring a range of parameters such as flow rate, pressure, temperature, fraction, seismic response, etc. Fiber Bragg gratings have proven themselves as reliable and accurate technology that can be applied in multilateral wells. These systems are installed in different operating environments all over the world. Fiber Optic Sensing Systems for Oil and Gas Wells

Distributed Fiber Optic Monitoring Systems’ Elements

Thanks to all the benefits, including a wide range of working temperatures and pressures, immunity to electromagnetic interference, and the possibility of usage in an adverse environment, fiber optic solutions have found many applications.

Any fiber optic sensing system consists of three components:

Fiber optic cable is suited to measure some physical effects with high absolute and local accuracy. Usually, cables are produced in such a way that the scattering effects are minimized. That allows maximizing transmission distance and data rate.
Analyzer or control panel is connected to the fiber optic cable and is designed to capture and collect data.
The final step is the interpretation and analysis of the whole received sensor data with the usage of the software. The software allows users to visualize strain or temperature data from the system.

The Most Common Fiber Optic Sensing Systems

There are two main types of fiber optic sensing systems: distributed acoustic sensing systems and distributed temperature sensing systems. Both of them have proven to be the most cost-effective and reliable fiber optic solutions and found their applications, including in the oil and gas industry. The main advantage of these systems is the ability to measure at each position where the fiber optic cable is installed.

Distributed Acoustic Sensing

DAS systems are optoelectronic instruments based on fiber optic technology that measures acoustic interactions all over a fiber optic cable. In DAS there is also an attached optoelectronic device that processes all the data from the cable. This technique allows acoustic frequency strain signals to be detected in harsh environmental conditions and over large distances. The sensing fiber is usually built on single-mode fiber. However, multimode sensing fibers can be also applied in some customized applications.

Distributed Temperature Sensing

DTS systems are optoelectronic instruments based on fiber optic technology that measures temperature all over a fiber optic cable. One of its advantages is providing continuous temperature information along the whole sensing cable. Moreover, specialists can predetermine the discrete sensing points for the most accurate data.

Nowadays, scientists are working in other directions. Since the invention of fiber optic technology, significant improvements have been made in both technologies and sensors. But for now, it is complicated to project a system that would combine DAS and DTS systems with the same optical fiber because of the different operation principles.

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Distributed Temperature Sensing (DTS) for ice sheets

Scientists from the UK have applied fiber optic systems to observe the Greenland ice sheet and get the most accurate measurements of ice characteristics. They chose distributed temperature sensing (DTS) as the main instrument for collecting data about the ice sheets melting. The results will be used to build more precise movement models of the second-largest ice sheet in the world.

Nowadays, the Greenland Ice Sheet plays a crucial role in the rising global sea level. The main reasons for the Ice Sheet’s mass loss are the meltwater runoff and the discharge of ice into the ocean by the glaciers. That’s why the scientists chose it for the research with the help of fiber optic systems.

The researchers applied modern fiber optic technology in order to determine the ice sheet movement. To discover thermodynamic processes within a glacier, they used distributed temperature sensing (DTS). According to the research, this fiber optic system consists of a 1000 meters length fiber optic cable that transmits laser pulses. In comparison with the previous researches, when the temperature was measured with separate sensors far away from each other, the fiber optic technology measures the temperature along the entire fiber optic cable. As a result, the scientists get a really detailed profile of ice sheet temperature.

First of all, the scientists drill through the glacier to install the fiber optic cable. Then they put it into the borehole. The research team transmits laser pulses in the fiber optic cable and writes any light changes down. The light changes demonstrate the different temperatures of the surrounding ice. And the last step is collecting the data and its analysis.

Thanks to the distributed fiber optic sensors, scientists have already found that the temperature distribution is diverse. This deformation is concentrated on the lines of ice that belong to different ages and types. Researchers suppose that it can be caused by the dust content of the ice or large fractures.

The great advantage of this fiber optic technology is the fact that the temperature can be recorded over vast distances and at high resolution. The scientists are working on the other aspects that could be useful in future research, for example, deformation.

The received data collected with the help of distributed temperature sensing systems allows developing advanced designs and models of the ice sheet movement. Fiber optic technology also will help to predict its movements in the future and define the approximate sea level rise.

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Distributed Sensing market and its growth forecast

Distributed Sensing market forecast According to the researchers, the distributed sensing market is predicted to reach more than $891 million by 2026. The distributed temperature sensing power cables and distributed acoustic sensing systems, as well as global environmental changes, are expected to increase the demand significantly. The modern advancements and developments connected with the light-sized fiber optic systems stimulate globally the distributed sensing market. Moreover, the growth of the distributed sensing market can also be explained by the government’s support for distributed temperature sensing technology.

Nowadays, there are many appliances of distributed sensing systems. There is an extensive need for monitoring continuous temperature changes within big territories and long distances, for example, in the oil sphere. The distributed temperature sensing systems are also applied in subsea areas. Distributed sensing can also help in providing security and productivity in different market sectors in the upcoming years. Moreover, fiber optic solutions are more often applied in fire detection processes.

In April the newly developed fiber optic system got a reward for the innovative approach and commercialization. The fiber optic system expands the coverage of distributed sensors. As a result, this innovation gives new possibilities in many fields such as energy, infrastructure, and environmental sectors. This fiber optic technology allows the collection of more precise data. That could lead to the improvement of sustainability, enhancing operational safety, and getting optimal costs for existing and new applications.

Distributed fiber optic sensors offer sensitivity 100 times greater than the usual ones. The higher sensitivity solves the emerging critical problem and challenges fast. That allows monitoring the situation continuously. This fiber optic technology also provides all the advantages such as carbon capture, improved geothermal systems, and dam integrity monitoring as well as subsea oil and gas wells.

In conclusion, distributed sensing systems are a very promising technology for many sectors. Thanks to the distributed sensors that are extremely sensitive to any slight changes, they can provide the most precise picture in comparison with other modern technologies.

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Distributed Temperature Sensing (DTS) measures moisture

DTS for moisture estimation Passive distributed temperature sensing (DTS) helps to improve the measurement of moisture content and temperature increase. The DTS technology has been already tested in China to prove the opportunities provided by this technique. Therefore, distributed temperature sensors are very promising for agriculture.

Several land conditions include bare soil, plastic mulch, plastic mulch covered with potatoes, and plastic much covered with maize. Land moisture plays a crucial role in influencing grain yield. Nevertheless, distributed temperature sensing is not suitable for the last type of land.

The thing is that several techniques allow for determining soil moisture content. Distributed sensing systems include point, ground, and regional types. Herewith, point fiber optic sensors consist of “oven-drying, neutron scattering, electrical impedance, time-domain reflectometry (TDR), frequency domain reflectometry (FDR), tensiometer, and thermal probe techniques.”

Conventional fiber sensors offer benefits of high precision and reliability but most of them are limited to a specific area. This is the main reason why it is difficult to determine accurately the overall ground moisture condition, especially in places where soil moisture distribution is discontinuous.

Thus, scientists have suggested applying distributed temperature sensing (DTS). DTS technology allows for estimating agricultural soil moisture, herewith, the distance of measurement can achieve several tens of kilometers. The operating principle of distributed temperature sensors is based on the heating of optical cables. When the temperature increases, the soil moisture can be estimated.

The DTS technology is not new and it quickly found the application in moisture measurement. According to this technique, it is possible to measure in situ soil moisture by employing analytical or semi-empirical models. Nevertheless, firstly it is necessary to calculate the thermal conductivity of the soil.

Compared to traditional techniques that have limitations, distributed temperature sensing allows for overcoming them. DTS estimates the temperature response of soil, therefore, measures soil moisture based on the data obtained by fiber optic sensors. Nonetheless, the proposed technique has several disadvantages.

Various weather conditions can influence the heat transfer way in the soil and the data obtained by distributed temperature sensors will be inaccurate. Additionally, boundary conditions and even time change periods also influence the precision. Finally, the standard algorithm is very difficult for application in practice.

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Distributed temperature sensing (DTS) in oceanography

DTS in oceanography The technology of distributed temperature sensing (DTS) is based on the application of Raman scattering from a laser beam light through optical fibers to detect temperature parameters along a fiber optic cable. The thing is that temperature resolution plays a crucial role. Herewith, this feature makes it possible to efficiently use DTS systems in oceanography.

Even though oceanographic applications of distributed temperature sensing are not new but such observations are not often. The reason is the serious challenges of deployment, calibration, and operation in oceanographic environment conditions. Nevertheless, researchers have tested the DTS system to overcome oceanographic configuration, calibration, and data processing difficulties.

It should be noted that they also evaluate temperature errors of DTS for several common scenarios. Difficult conditions influence the whole process, thus, the researchers look for alternative calibration, analysis, and deployment methods for distributed temperature sensing.

Therefore, these errors will be reduced and the successful application of DTS systems will be increased in dynamic ocean conditions. The thing is that DTS technology allows for “continuously sampling at a relatively high temporal and spatial resolution for significant duration over broad spatial scales.”

Despite distributed temperature sensing is widely applied in environmental applications, the oceanographic area remains challenging and still relatively rare. The main purpose of new DTS development is the solution to common problems present in oceanographic deployments.

To be more precise, the researchers use 2 various DTS systems, 3 fiber optic cables, and 24 thermistors. All of them help to test cables and different calibration configurations and perform distributed temperature sensing. Test results enable them to improve future oceanographic deployments. Moreover, they aid to achieve the best possible temperature signal in difficult deployment and operational environments.

DTS technology is a relatively new oceanographic tool. It allows for detecting temperature across wide spatial and temporal scales. Herewith, the application of such a fragile DTS system in remote and dynamically complex conditions remains difficult. Moreover, sometimes it is impossible to perform distributed temperature sensing at all.

Additionally, DTS systems face challenges during the detection of air/sea boundary. The reason is the change of water level, for instance, tides, waves, surge, etc., when the fiber optic cable can be exposed. Finally, the new DTS has succeeded to detect the temperature variance between the air-sea interface.

If you want to obtain a highly efficient distributed temperature sensing system, you should choose the Optromix company. Optromix is a manufacturer of innovative fiber optic products for the global market. The company provides the most technologically advanced fiber optic solutions for monitoring worldwide. Optromix is a fast-growing vendor of fiber Bragg grating (FBG) products line such as fiber Bragg grating sensors, FBG interrogators and multiplexers, distributed acoustic sensing (DAS) systems, distributed temperature sensing (DTS) systems. If you are interested in DTS systems and want to learn more, please contact us at info@optromix.com

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