Tag: fiber optic sensors

FBG sensors for monitoring of overhead transmission systems

FBG sensors for transmission system monitoring Now it is highly important for the industrial sphere to have the ability of overhead transmission systems monitoring technology with the aim of potential error identification that can touch vital components. The main reason for severe mechanical errors is different in extreme situations. Consequently, the monitoring system of excessive mechanical and environmental loadings is the only significant solution to find and prevent potential risks.

The fact is that there are numerous factors that can occur in overhead transmission systems and cause different loadings. For example, the loading conditions include:

excessive bending;
aeolian vibrations;
galloping;
ice loading and shedding;
the impact from falling objects;
hot spots;
aging;
galvanic corrosion, and others.

Herewith, these factors could severely damage the structural integrity of the conductors but for fiber Bragg gratings sensors for transmission monitoring.

Thus, a novel composite based overhead transmission lines were designed in response to the world’s increasing level of electrical consumption. Moreover, these FBG conductors are able to maintain severe environmental conditions, and they are considered to have a high period of service that can last for many decades.

It should be mentioned that previous monitoring systems of transmission lines were very difficult or even sometimes impossible process. Nowadays modern monitoring technology allows reducing costs on maintenance and inspection, and it is also able to make life predictions of the transmission systems.

This monitoring system uses optical sensing technology in high voltage environments whose main benefit is the immunity to electromagnetic interference and low signal weakening that make the system ideal for power transmission structures.

Also, FBG sensors include conventional single-mode optical fiber that enables to measure temperature and strain of live lines in-service. Herewith, the process of monitoring can be made from miles away without conductive materials. The data obtained by strain signals processing from static and dynamic loads can be used for the detection of conditions that can affect the conductors.

The application of FBG monitoring technology also includes the assessment of the structural system health as well as the identification of the impact location relative to the position of FBG sensors along the conductor. Finally, the development of an FBG monitoring system will provide better control and maintenance procedures for the conductors of different types.

Optromix is a fiber Bragg grating (FBG) products manufacturer that offers FBG sensors, FBG interrogators and multiplexers, DAS systems, DTS systems. Optromix creates and supplies a broad variety of fiber optic solutions for monitoring worldwide. If you have questions or would like to buy FBG products, please contact us at info@optromix.com

Fiber optic spark monitoring for EDM

FBG sensors for EDM EDM or electrical discharge (spark) machining is the most advanced of metalworking technologies. EDM is worldwide used because of its high accuracy and machining applications where traditional metal removal is highly difficult or even impossible.

The principle of EDM operation includes the spark that moves from the wire electrode to the work item approximately at the same speed as the electrical signals transmitting through the wires of the monitoring system. Nevertheless, the distance between this work item and the wire electrode is shorter than the space interval between the spark and the control, that is why there are some difficulties in monitoring.

Thus, spark monitoring is very important and needs some technical improvements. Fiber optics is the best solution for the challenge that provides a high level of process control, increases the life of the wire, and eliminates the possibility of wire damage. Moreover, the use of a fiber optic spark monitoring system improves the problem of slow electrical signals and thereby, allows making timely all required adjustments and maintaining permanent sparks.

The main aim of fiber-optic cable use is the reduction of wire wear to save costs for the user. For example, previous machines had stronger sparks and low frequency that provoked high wire pressure. Novel fiber monitoring systems have a higher number of sparks per second with less intensity.

It should be mentioned that fiber-optic cables are not limited by the electricity speed comparing to electrical wires because fiber cables transmit data through light pulses. Moreover, they are almost one hundred times faster than electrons. This improvement allows not only reducing wire wear but also keeping spark output and decreasing the necessary voltage.

Also, fiber optic cables leave behind electrical wires because of the following reasons:

safety due to nonconduction of fiber optics;
lightness despite the required power and distance;
higher data bandwidth at longer distances;
faster transmission speed;
the thinness of the cable;
the durability of fiber cables;
better reliability;
lower total costs.

Optromix is a manufacturer of innovative fiber optic products for the global market. The company provides the most technologically advanced fiber optic solutions for the clients. Optromix produces a wide range of fiber optic devices, including cutting-edge customized fiber optic Bragg grating product line and fiber Bragg grating sensor systems. Moreover, Optromix is a top choice among the manufacturers of fiber Bragg grating monitoring systems. If you have any questions, please contact us at info@optromix.com

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FBG biosensor is able to detect thrombin in human blood

FBG sensors for thrombin detection Thrombin plays a very important role in normal and pathological blood coagulation because its high level is an indication of tumor cell presence. Also, the level of thrombin is growing while atherosclerosis, thromboembolic disease, cancer, and inflammatory disease. Thus, its clinical importance provokes the development of devices for fast and precise thrombin detection and most of them are based on aptamers.

One of the ways to solve the problem is the use of optical-fiber grating-based sensors that have a great range of advantages:

high level of sensitivity;
multiplexing ability;
compact size;
lightweight;
possibility of multi-modal sensing;
tolerance to electromagnetic interference;
low manufacturing cost.

All FBG sensors are based on different operation principles. There are LPG, etched fiber Bragg gratings, tilted FBG, microstructured Bragg gratings, photonic crystal fibers, or PCF. Nowadays the development of these types of sensors, especially, those which can detect thrombin, is the primary objective.

Etched fiber Bragg grating (EFBG) is one of them, its manufacturing is highly simple and fast because it has chemical etching liquids (for example, hydrofluoric acid) that are able to take away the cladding very quick at a controlled rate. Also, EFBG differs from core-exposed micromachined gratings by the absence of a laser micromachining station that makes the process of fabrication harder.

In spite of the fact that etched fiber Bragg gratings sensors have less sensitivity than in other types, there are numerous advantages over these sensing devices. For example, EFBG systems obtain simple adjustability of their sensitivity. Moreover, there is no need for a polarization control because etched Bragg gratings measure reflection.

This optical-fiber grating-based sensing system operates with a wavelength of 1550 nm, uses hydrofluoric acid as etching fluid for approximately 27 minutes. It is able to detect thrombin in concentrations ranging from 10 nM to 80 nM and the use of EFBG has a promising future as the manufacture of FBG biosensors needs only chemical etching, also it is simple and less expensive than other types of sensing systems. Moreover, etching fiber Bragg grating sensors are easy for multiplexing and, consequently, can be used in vivo. Finally, all the advantages expand the opportunities for thrombin detection.

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Bioresorbable Fiber Bragg Grating sensor advances medicine

bioresosbable FBG sensor Today environmental change provokes the appearance of new diseases and, finally, human health care requirements continue increasing for several decades. Moreover, it is necessary to have new advanced tools for the disease diagnosis at early stages, for monitoring and treatment of patients. Then unconventional biomedical instrumentation and sensors, including optical-fiber sensors come for help to modern medicine. And devices with bioresorbable fiber sensors increase the efficiency of monitoring and treatment.

Fiber Bragg Grating (FBG) is one of the most productive ways suggested for fiber-based biomedical sensing. Fiber Bragg grating sensing technology provides a new and effective way of real-time measurements. The fields of FBGs application contain biosensing, safety or security, and structural-health monitoring. Also, FBG sensors are highly suitable for laser systems, medical tiny intra-aortic probes, and body sensors for biochemical analysis making.

Modern Fiber Bragg Gratings use bioresorbable optical-fiber sensing probes that have such ability as controlled solubility in a physiological environment. A bioresorbable material is the main component of FBG sensors and the human body easily and safely assimilates it at a special time interval. The technology allows safer diagnostic of sensitive human organs and there is no need for a surgical extraction. Fiber Bragg Gratings sensors are easy to install and use, their sensing points have quite high density. It is an ideal, cost-effective, and accurate technology for extreme environmental conditions.

The advantages of optical fiber include:

good mechanical durability;
high optical transmission;
stoichiometrically tunable dissolution rate.

It should be mentioned that tilted Bragg gratings with a 1-degree tilt angle that are immersed in phosphate-buffered saline solution with temperature and pH conditions similar to those of the human body allow fiber dissolution studying. Finally, selective chemical-etching effects were found out thanks to scanning electron microscope images and micro-Raman spectroscopy.

Thus, bioresorbable fiber Bragg grating sensors are considered to be effective for the development of soluble, compact photonic sensing probes that can be used for in vivo monitoring of vital mechanical or chemical factors with a specific time limit, and also in controlled in-body drug delivery.

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. Optromix creates and supplies a broad variety of fiber optic solutions for monitoring worldwide. The range of services includes research programs, interpretation reports, layout design, system software modeling, commissioning, user training, real-time data transition, equipment supply, ground part installation, engineering, and technical support. If you have questions or would like to buy FBG products, please contact us at info@optromix.com

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Fiber Bragg Grating Based Chemical Sensors

Fiber Bragg grating (FBG) can be used as miniature, inexpensive, and lightweight strain, temperature, and pressure sensors for applications such as real-time health monitoring of aircraft, space vehicles, and smart materials and structures. Nowadays only a few applications of FBGs in chemical sensing have been reported.

The key to a chemical sensor using an FBG lies in the transfer of stress from a swelling material, such as a polymer, to the FBG, resulting in a measurable strain via the shift in resonant Bragg wavelength.

The main principle of FBG sensors for applications in chemical sensing is based on the axial strain of the fiber. The chemicals that surround the fiber cause it to shift and, deform. The strain caused by the presence of a particular chemical causes the spectral pattern of reflected light to change; the shift in reflected wavelength is observed. To monitor the shift in wavelength FBG interrogators are used. The data gathered by the interrogator can then be converted to environmental concentrations.

The key component of fiber Bragg grating sensors for chemical sensing is a highly sensitive coating. The coating should be stiff and adhere easily and firmly to the glass fiber. Most often the coating is based on polymers. However, the coating needs to have a high modulus of elasticity that remains high at high temperatures and during analytes absorption. Most polymers are restricted by temperature due to softening and material relaxation.

Some ways of FBG sensors polymer coating include:

improved coating processing;

The improvement of the coating process, like improved adhesion, may aid in the reduction of material relaxation and shifting. The glass fiber may be treated before the application of polymer coating for improved adhesion.

improved data processing;

The use of two different coatings that respond in equal, but the opposite manner to environmental changes. The combination of the two responses limits the temperature drift.

improved material properties.

Alternative coatings, like ones based on ceramic materials, may expand the temperature application range.

Chemical sensing is a developing field of fiber Bragg grating sensors. It is involved in the control of chemical processes, oil recovery, environment quality improvement. There are several factors that play a role in the implementation of chemical sensors – suitability for remote sensing, sensitivity, low costs, selectivity, ability to work consistently in harsh environments. The oil and gas applications require sensors that can withstand high temperatures and pressures, and environmental sensors must have a wide coverage area and limited signal fluctuations.

Fiber Bragg grating sensors have been used in numerous applications, including aircraft monitoring, structural health monitoring, strain, and temperature measurements. In the last decade, FBG sensors have been implemented as chemical sensors due to their ability to withstand high temperatures, immunity to electromagnetic interference, and the absence of electronics.

Optromix, Inc. is a U.S. manufacturer of innovative fiber optic products for the global market, based in Cambridge, MA. Our team always strives to provide the most technologically advanced fiber optic solutions for our clients. Our main goal is to deliver the best quality fiber optic products to our clients. We produce a wide range of fiber optic devices, including our cutting-edge customized fiber optic Bragg grating product line and fiber Bragg grating sensor systems. Optromix, Inc. is a top choice among the manufacturers of fiber Bragg grating monitoring systems. If you have any questions, please contact us at info@optromix.com

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Fiber Optic Sensing: Fiber Bragg Grating Sensor Interrogation Systems

FBG sensor interrogator systems can be deployed into a variety of fields. These products feature high reliability, advanced command and data output control, and incredible speed and sensing range.

Fiber Bragg grating (FBG) sensors have been well known and widely used for around 20 years for the following reasons: they are light, compact, easy to install, require very low maintenance, can be used in highly explosive atmospheres, and are immune to electromagnetic interference. Fiber optic sensors have a wide range of possible applications, which include temperature sensing, strain and bending measurements, medium refractive index measurement.

Despite numerous advantages of fiber optic sensors, it is important to install an FBG interrogator to retrieve accurate data and measurements from the sensors. Here is the main principle of how the fiber optic interrogator works: after the light has been sent into the fiber and has been reflected from the FBG, it travels to the interrogator – it’s photodetectors – which then compares it to the wavelength reference artifacts; after that, the interrogator determines the position of the FBG center wavelength. This information is later converted to some measurement units.

There are multiple types of FBG interrogators; each type offers different advantages over others, for example, the number of optical channels and Wavelength range. For example, high-frequency FBG interrogators provide an opportunity to work with dozens of fiber optic sensors at high speed. This characteristic also provides an opportunity to use multiple fiber optic interrogators at once.

The wavelength range of the FBG interrogator plays an important role when it comes to how many wavelengths or bandwidth information from an FBG sensor it can process. Some FBG interrogators have a very limited wavelength range, only around a few nm, however, this is not ideal for most FBG systems. The broad wavelength range of the interrogator provides better measurements.

Another important characteristic of FBG interrogator is the number of optical channels. Each channel represents an optical line, therefore, the bigger the number of optical channels, the more optic lines the interrogator can handle at once. Most interrogators have one optical channel and dedicated to one particular optic line.

Other approaches to FBG sensor interrogating, some of which include:

Broadband source, Dispersive element, Diode Array;

This method is less reliable than the aforementioned ones due to limited resolution, which is a result of the inherent limitations of commercially available diodes.

2.Broadband source, Optical Spectrum Analyzer/Multi-line wavelength meter;

optical spectrum analyzers are large and expensive, which makes them less desirable in a laboratory setting. They are also not able to perform optimally under some temperatures.

3.OTDR/TDM systems;

The system cannot handle a large number of sensors on the fiber as its data acquisition rates scale down with increasing sensor counts.

4.External Cavity Tunable Laser, Power Meter, Wavelength Meter;

External cavity tunable lasers have low speed and do not have a wide operating temperature range. Moreover, they are expensive and do not have the required mechanical robustness.

Optromix interrogators can control up to 8 optical channels. The interrogator operates with the 20 maximum sensors per channel. The device is controlled by the PC with the specialized software for sensors monitoring. The system contains a broadband source of radiation and it can carry out spectrum analysis.

If you have any questions, please contact us at info@optromix.com

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Optical Pressure Detector for Improving Robot Skin, Wearable Devices, and Touch Screens

A new type of fbg pressure sensor based on light could allow the creation of sensitive artificial skins to give robots a better sense of touch. The silicone sheet can be placed on display panels to enable touch screens or can be wrapped on robot surfaces as an artificial skin layer for tactile interactions. In addition to this, such a new sensor could allow the creation of optically transparent touch screens and devices and wearable blood-pressure monitors for humans.

Researchers from the Electronics and Telecommunications Research Institute (Daejeon, South Korea) and Hanyang University (Seoul, South Korea) developed a flexible, transparent fiber optic device that detects pressure by analyzing changes in the amount of light traveling through tiny tunnels embedded in polydimethylsiloxane (PDMS), a common type of silicon. This device is sensitive to even gentle pressure and is less prone to failure compared to previous types of fbg pressure sensors. It also should be feasible to incorporate the embedded optical sensors across a large surface area.

The fiber optic device works by measuring the flow of light through a precisely arranged pair of optical waveguides called a photonic tunnel-junction array. The waveguides run parallel to each other and are embedded in PDMS. PDMS is a very well-known biocompatible, non-toxic material, so the sensor sheet may even be applied on or inside the human body, for example, to monitor blood pressure.

Several steps are needed to move the sensor from a laboratory demonstration to a practical device. In developing the prototype, the research team used precision alignment tools, which would be too expensive and time-consuming to use in most commercial applications. An alternative approach, pigtail fibers, which telecommunications companies use to couple fibers in their systems, should make the process easier.

If you have any questions, please contact us at info@optromix.com

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Strain Measurement with Fiber Bragg Grating Sensors

Scientists and engineers can perform through the implementation of optical sensors measurements that were previously impractical or, in some cases, impossible with vibrating wire or foil gases. Many applications will require a hybrid approach using the benefits of both electrical and optical measurements together. Fiber Bragg gratings are often used in strain sensing especially in such places where the environment is harsh (for instance, high-EMI, high-temperature, or highly-corrosive). Strain measurement is imperative during prototype design and testing. Strain measurements ensure that materials perform as they should and that the equipment is safe and durable. Measuring strain is crucial for testing complex structures, like aircraft, turbines, etc.

Fiber Bragg grating strain sensors have been infrastructure monitoring of smart structures like bridges, dams, pipelines. By monitoring load, strain, temperature, vibration, and even liquid of gas flow, structural integrity can be assessed and tracked on a real-time basis. There various ways in which stress can be measured, but it is widely accepted that FBG sensors are the most efficient way of strain measurement.

There are two types of applications of the fiber Bragg grating strain sensors:

Long-term Static Strain Sensing. The main issue in the long-term static strain test is an interest in measuring the long-term static strain of the component in question. In order to carry out the above operation, it is necessary to set up the grating on the structure, find out what the initial wavelength is, and then within a set period of time to detect and record the changes that have occurred. Also, it is possible to return to the structure, reattach, and refer back to the initial wavelength. As a result, it becomes possible to obtain the determination of what this strain is from the initial condition at that time. The ability to disconnect your monitoring instrumentation and return for results after a large amount of time such as months or even years is a very great advantage of fiber Bragg grating sensors. For instance, in the case of bridges, it is common for engineers to visit the bridge and conduct the impact testing using an impact hammer on the different parts of the bridge. This is time-consuming and even hazardous because of the height of some bridge structures. The distribution of a number of FBG sensors throughout the bridge and the attachment of the instrumentation to this bridge on a periodic basis is a much more efficient solution. This is only one of the good examples to demonstrate the effectiveness of the fiber Bragg grating strain sensors. Besides bridges, other examples of using FBG for long-term static strain testing are buildings, piers, and structures in high earthquake-prone areas.
Dynamic Strain Sensing. The different structures may have very-low-frequency modes, and they may also have higher modes due to the effects of wind and tide. Most earthquakes and other earth tremors are low-frequency events. Fiber Bragg gratings can be attached to the structures and monitored for the vibrations during the earth’s tremors and earthquakes. The low-frequency dynamic strain testing can help in determining the reaction of high-rise buildings to the wind. In addition to this, FBG sensors create connections with peers and other shore structures to determine their vibrations during the ebb and flow of tides. Dynamic strain testing can also be performed on transportation vehicles like automobiles, trains, and airplanes. In addition to civil structures and vehicles, there are a number of other applications for dynamic strain testing and vibration stress testing using fiber Bragg gratings. FBG sensors can be attached to industrial machinery to determine the frequency and amplitude of the stress vibrations.

If you would like to purchase Optromix FBG Strain Sensors, please contact us: info@optromix.com or +1 617 558 98 58

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Fiber Bragg Grating Strain Sensors for Creating Modern Sophisticated Equipment

Strain measurement is imperative during prototype design and testing. Strain measurements ensure that materials perform as they should and that the equipment is safe and durable. Measuring strain is crucial for testing complex structures, like aircraft, turbines, etc. There multiple ways in which stress can be measured. However, it is widely accepted that FBG sensors are the most efficient way of strain measurement. FBG sensors provide multiple advantages over other methods:

1) high sensitivity;

2) small size;

3) ability to be mounted on any surface;

4) immunity to electromagnetic interference;

5) reliability even in harsh environments;

6) low sensitivity to vibration and heat.

FBG strain sensors are used in wing load testing to determine the structure’s performance and possible limitations under the lifting forces during flight. There are several benefits that FBG strain sensors offer to the aerospace field for this type of application. For instance, FBG technology provides strain measurement using a big number of continuous sensors which ensures maximum coverage from a single optical fiber. The immunity to electromagnetic interference, radio frequency interference and other electrical influences makes FBG strain sensors ideal for use in hazardous environments, such as flight. Also, FBG sensors are less cumbersome to install. In addition, the FBG strain sensor prices are expected to decrease by 20% which will open up new opportunities for various markets.

The repeated loading and unloading of a material causes fatigue. It is estimated that around 90% of structural failures are a result of fatigue. To determine the breaking point of a structure, fatigue tests are performed. The tests indicate the number of loading cycles until failure. FBG sensors are able to provide real-time data on strain fields and load distributions. The immunity to both low and high temperatures enables the sensors to be monitored during the high-temperature cure phase of composite fabrication. The fatigue life of an FBG strain sensor far surpasses that of other methods of strain measurement.

The tendency to build longer wind turbines with longer blades complicates the maintenance. The design of stronger, lighter materials is necessary, however small imperfections during the manufacturing process can cause failures. FBG strain sensors may provide real-time knowledge of load distributions and turbine blade shape. This data will provide valuable information on the needed adjustments to the blades manufacturing.

If you have any questions, please contact us at info@optromix.com

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Development of Fiber Bragg Grating Sensors for Aircraft Structural Health Monitoring

The use of composite materials in modern aircraft has been growing because of the numerous advantages that they provide. Generally, composite materials are less sensitive to corrosion, have enhanced fatigue behavior, and higher specific mechanical properties when compared to traditional materials used in aerospace applications. By contrast, composite materials have problems with damage detection which is an important procedure in the air transport industry. The main issue that occurs during the process of use is the separation of laminae from each other which happens on the inside of the material and is hidden from the outside. Nondestructive methods of aircraft testing are not effective enough for material monitoring.

Structural health monitoring consists of placing measuring and sensing devices on a structure to record, localize, analyze, and eventually predict damage. Most structural health monitoring techniques strive to measure the needed data in a non-destructive way. Fiber Bragg grating sensors are optimal for measuring different variables as they are more cost-efficient, easy to implement on most surfaces, including composite materials.

Aircraft structures require regular, scheduled inspections and monitoring of all possible hazards due to their special conditions and the principles of their design. Therefore, structural health monitoring is conducted through fiber optic devices and has great potential to reduce the costs related to these operations. Fiber Bragg grating sensors have proved to constitute the most promising technology in this field. In order to prolong the operation period of all kinds of complex engineering systems and avoid catastrophic failures, so it is necessary to achieve the highest levels of damage detection. The automation of the inspection process is a point of major importance to reduce inspection efforts. The structural health monitoring system on the basis of fiber optic products can be defined as a set of devices that provide information that allows us to locate, evaluate, and predict the loading and damage conditions of a structure. The structural health monitoring of aircraft structures can conduct real-time checks, reducing costs, and improving the reliability and performance of the structures. A wide range of potential structural health monitoring technologies is being developed to meet these needs, and the most promising options are:

electrical strain gauges and crack wires
acoustic emissions methods
optical-based technologies
comparative vacuum monitoring
microelectromechanical systems (MEMS)

Fiber optic products and fiber optic devices, in general, are very appropriate to perform structural health monitoring due to the fact that they have their intrinsic capabilities, such as sensitivity to electromagnetic radiation, low weight, compact size, great sensitivity and resolution, and their suitability to be embedded into structures. Fiber optic devices for monitoring the strain in aircraft structures can be classified into the following categories: intensity-based, interferometric, distributed, and grating-based fiber optic devices.

Among grating-based sensors, FBGs and probably the most mature and widely employed optical sensors for structural health monitoring of engineering structures due to their fast development achieved in recent years.

Optromix is a fast-growing vendor of fiber Bragg grating (FBG) products line: fiber Bragg grating sensors, FBG interrogators and multiplexers, distributed temperature sensing (DTS) systems. We create and supply a broad variety of top-notch fiber optic solutions for the monitoring of various facilities all over the world.

If you are interested in Optromix FBG sensors, please contact us at info@optromix.com

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