Tag: fiber optic systems

Fiber Bragg Grating Sensors for Weigh-in-Motion strips

Nowadays, road safety has advanced to a new level with the use of fiber Bragg grating sensors. Due to its characteristics, fiber optic technology has become part of the other technologies. For example, FBG sensors are applied in WIM systems (or Weigh-In-Motion systems) for that purpose.

There are several types of WIM systems and one of them is based on fiber Bragg grating sensors. Such systems provide specialists with the most accurate and detailed data around the clock, monitoring traffic flow. They are able to detect the vehicles and in the meantime determine their weight during the regular traffic. The traffic monitoring in real time allows improving the enhancement of traffic management.

Moreover, fiber Bragg gratings (FBGs) are used in WIM systems for the structural health monitoring, for example, of the bridges or rails.

What is Weigh-in-Motion (WIM) Technology?

Weigh-in-motion (WIM) systems are based on technology that allows providing reliable weight measurements of the vehicles. The systems can be applied whether for specific road or rail vehicles such as trucks and trains, or for public applications like be set on the rail or road tracks to monitor the traffic. Weigh-in-motion systems built on fiber Bragg grating sensors measure the traffic flow and supply all the information from it. Thanks to the durability and quality of FBG sensors, the necessary data is provided using one of the most cost-effective methods.

The whole fiber optic system consists of a range of sensors and a roadside unit with all the data devices. According to the application purposes, there is an opportunity to add other fiber optic sensors to this weigh-in-motion system, for instance, temperature sensors. Moreover, to receive more data about the vehicles, it is possible to use cameras for license plate photos.

What Information do the Weigh-in-Motion Systems Provide?

Fiber optic sensors follow two basic physical principles. The first principle that belongs to fiber Bragg gratings is the diffraction changes under the deformations. The second one is the changes of the optical fibers and their characteristics under the influence of the deformation. Therefore, the WIM systems provide all the characteristics that fiber optic technology offers.

The reliable data on weight from fiber optic sensors give an understanding of the loading of heavy goods vehicles and traffic flow. FBG sensors will help in estimation, avoiding any inaccuracy in the future. This, in turn, will allow improving the goods transportation and infrastructure management.

Except for the usual weight parameters that fiber optic systems provide, there are other available options, such as date-time, speed and classes of vehicles. To efficiently operate, the fiber optic systems can be installed on the specific vehicle or placed by the road for the entire traffic flow monitoring.

Advantages and Disadvantages of the Fiber Optic Sensors

As any technology based on fiber optic sensors, WIM systems possess all the features that FBG sensors have. Such characteristics as light weight, small size and insensitivity to the electromagnetic fields and weather conditions are really important in monitoring systems. Moreover, WIM systems have an ability to identify the underinflated or double tires in the traffic stream.

Weigh-in-motion systems help in providing very short response time in operations. However, there is a possibility of some inaccuracy of weighting, especially in motion. That’s why specialists are aiming at enhancing the same level of accuracy in motion as in static. And sometimes there is no use in enhancing the fiber Bragg grating sensors’ accuracy level, but increasing the number of sensors or making the automatic calibration processes better. There is a range of external factors that influence fiber optic sensors’ operation such as vehicle suspension, road roughness, etc. Moreover, they can influence the accuracy level in a bad way.

The most commonly agreed disadvantage is relatively high cost for electronic equipment. However, due to the long service life of fiber optic sensors, WIM systems seem to be a cost-effective technique by operating for at least 10 years.

Applications of the Weigh-in-Motion Systems

Fiber optic solutions are applied for many purposes as WIM systems. If it is needed, WIM unit can provide several data parameters at once. Usually, such data is applied in the following spheres:

Vehicle and traffic loading. As it was mentioned before, the information on the traffic flow helps in optimization and planning of the road network in the future. Or the researchers frequently apply it for carrying out the studies. However, there is another implementation that can be used for the already existing infrastructure – for example, for the review of the traffic flow over the road network and its future development with time.
Weight enforcement is aimed at complying with loading regulations. This will lead to the decline of the overloading numbers that have negative implications. These WIM systems based on the FBG principles provide the most effective instrument of weight enforcement.
WIM systems based on the FBGs can also be applied for industrial use like in logistic centers or at ports. They are most commonly needed in the weight check and defining of the trucks’ axle loads. All these measures are aimed at avoiding overloads and their possible future consequences of entering the road network.
WIM systems with fiber optic sensors for the railway industry are as well effective as DAS systems described in previous articles. The most common ways of application in this sphere are the total track loading and dynamic wheel loads. In practical terms, the provided data helps in design and maintenance of the rail tracks.

In the future WIM systems with fiber optic sensors will allow creating one of the base elements of the “Smart City” concept. The FBG sensors are able to provide the system that with different types of sensors will form a complex and reliable technology. Moreover, the improvement of the weigh-in-motion systems based on the fiber Bragg grating sensors will lead to the decrease of overloaded trucks on roads.

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

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.

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.

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Fiber Optic Sensors’ development as wearable

Over the last few decades, scientists could achieve considerable progress in creating wearable sensors. Wearable sensors are newly developed inventions that can detect physiological and biochemical markers for health monitoring. Fiber optic solutions such as fiber optic sensors were no exception and made a great contribution to this technology.

What are wearable sensors?

Wearable sensors have an enormous potential for the early detection of many diseases including Covid-19 by measuring numerous vital signs such as blood oxygen level, respiratory rate, etc. According to the studies on Covid-19, the most common symptoms are shortness of breath, fever, and fatigue. Moreover, the blood oxygen level of an infected patient is lower because it is a respiratory disease. That’s why it was important to create a fiber optic technology capable of providing accurate data that would be useful for specialists and non-specialists alike people in quarantine or self-isolated.

Fiber optic sensors for medicine

Fiber optic sensors have attracted attention by development as flexible sensors. They usually consist of optical gratings and optical fibers embedded into polymeric matrices. For example, wearable systems based on fiber Bragg grating (FBG) were developed for biomedical usage. Thanks to their small size, lightweight, and other advantages, they can be easily integrated into polymers or textiles.

FBGs were suggested as wearable sensors for respiratory measurement for the upper body like abdomen and chest movements. FBG output changes can show the respiratory rate and breathing pattern. Moreover, with the help of fiber optic sensors, specialists are able to receive information about cardiac activities. The suggested fiber optic system has high sensitivity and can respond to environmental factors, for instance, relative humidity, temperature, and water immersion. Researchers noticed that the temperature had more influence on them in comparison with water immersion and humidity. That means that this fiber optic system needs further investigation.

The new humidity sensors were also developed based on optical fibers. The humidity also influences the light intensity of the emitted light of optical fibers. This function was used for developing a fiber optic system to measure the level of the nasal exhaled breath for respiratory rate tracking. In this system, scientists have placed a Fiber Bragg grating in an agar substrate. This device with fiber optic sensors demonstrated reliable performance and nice sensitivity to relative humidity change.

Thanks to the newly designed wearable fiber optic sensors, it became possible to integrate the health data of each person and find the best option for him.

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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FBG Interrogators with a size of a memory stick

Fiber optic sensors are a modern technology that helps in shape and temperature measurements in various spheres and industries, for example, civil structures, aircraft, medicine, etc. Scientists from all over the world aim to create the most compact and cost-effective device according to the market demand. So the specialists from Europe have produced the new memory stick-sized FBG Interrogators.

Fiber optic sensors’ nature

Fiber optic sensors have many characteristics that make them very effective for a multitude of applications. They are small, inert to chemical substances, immune to electromagnetic interference, and capable of withstanding high temperatures. There is no doubt that they have a lot of applications thanks to their unique characteristics. Fiber optic sensors are applied in structural health monitoring. In medicine, they are also used in catheters, endoscopes, etc.

Over the last years, scientists have developed fiber Bragg grating (FBG) sensors that can measure strain and temperature. For example, fiber optic sensors are successfully applied in the new generation of planes. The whole principle of the fiber optic sensors is based on the reflected light. The light is sent through a fiber optic cable and partially reflected by a microstructure inscribed into the fiber core. Researchers can observe different changes in strain or temperature thanks to the shifts in the wavelength of the reflected light.

Modern sensor devices such as FBG interrogators are based on free-space spectrometry. Spectrometers measure the properties of light in a specific part of the electromagnetic spectrum. However, this approach still has several limitations including measurement resolution, power consumption, etc. That is why scientists aim to develop fiber optic technology further.

The new generation of FBG interrogators

As fiber optic technology develops, scientists create new ways of device dimensions, power, and cost consumption to serve the increasing applications and clients’ requirements. There are many types of FBG interrogators that can include multiple photonic functions in one device. These devices represent the second generation on the market responding to the clients’ demands.

Nowadays, scientists even work on the third generation of fiber optic systems that have the size of a memory stick. With the size optimization, they also make the cost-effectiveness better. The new fiber optic technology includes a photonic submodule that consists of two light sources and a spectrometer section. Scientists have added three thermistors to measure the temperature of those three parts. The small box that has a size of a memory stick detects the reflected light that’s coming in on the fiber. The light is produced by one of the two light sources inside the model, injected into the fiber. The photodiodes record the reflections and the electronics amplify them.

Despite all the advantages of these new fiber optic systems, the future market adoption needs a more compact and lower-cost solution, including the costs of the consumables in medical and fiber optic battery monitoring systems.

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Distributed Sensing market and its growth 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 Acoustic Sensing (DAS) in exploring the ocean

Exploring the underwater environment that covers most of the Earth’s surface is one of the most difficult tasks. The easiest way is the usage of distributed acoustic sensing (DAS) technology. However, the fbgs sensors’ setting is also not so easy because of the environmental conditions. Despite this fact, distributed acoustic sensing has a huge potential for observing processes in the future.

Fiber optic solutions are the new methods of geophysical information registration that can be applied both onshore and offshore. The scientists used transmission time-of-flight of laser pulses inside transoceanic subsea fibers to note seafloor strain. To explore seafloor strain with higher spatial resolution, they utilized a distributed acoustic sensing (DAS) system.

Distributed acoustic sensing technology helps to observe the ocean and solid earth phenomena. The scientists applied a fiber optic cable and a distributed acoustic sensing (DAS) unit operating onshore. DAS technology uses a photonic device that sends short pulses of laser light through fiber optics. DAS detects the backscattering set by strain in the cable caused by stretching.

The researchers could get even more data than expected. They could record underwater earthquakes, volcanic activity, and a range of micro hydrodynamic signals. The scientists monitored the acoustic waves by alterations in laser light along the fiber optic cable. Recordings of a small earthquake wavefield demonstrated several fault zones underwater. Distributed acoustic sensing could picture earthquake hazards in the coastal oceans and give new data about fault orientations and seafloor structures. The DAS system displayed the state of the sea and its changes during a storm cycle. These observations proved the necessity and potential of this method for marine geophysics.

There are still aspects of this distributed acoustic sensing research that should be improved. One of them is the fact that current DAS instruments can only see lower frequencies. However, such frequencies are considered to be low for acoustics, but it is high for seismologists and enough to locate boat signals. The research team also explores the possibilities of tracking mammals, for example, whales with the help of distributed acoustic sensing technology. The second challenge is the fact that the scientists don’t know where exactly the fiber optic cable is. Because seabed bathymetry can affect the signals and influence DAS senses. Nowadays, it is possible to use only the initial part of the fiber optic cable, up to 200 km. But it already allows capturing a number of spheres of science.

As a result of the research, the observations with the DAS system during just a few days helped to create a map of an unknown fault system and detect several dynamic processes in the water. The distributed acoustic sensing technology could help to get rid of a huge gap in ocean sensing.

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

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