FBG Sensors for power plants

FBG Sensors for power plantsNowadays researchers tend to use fusion as a safe energy source at power plants. Nevertheless, this process is dangerous. It requires reliable fiber optic technology for structural health monitoring at power plants. Novel fiber optic sensors offer robust operation in the harsh conditions of a commercial fusion power plant.

To be more precise, these fiber sensors provide temperature sensing applying optical fibers with written fiber Bragg gratings (FBGs). The FBG operating principle is based on broadband light that is directed on it. Although most of the light goes through, one wavelength is reflected. Herewith, the reflected wavelength changes with both temperature and strain.

Therefore, the installation of several fiber Bragg gratings enables performing independent temperature sensing of each location. Standard FBGs are widely used in various industries for strain and temperature sensing. Herewith, compact superconducting cables use these optical fibers based on fiber optic technology.

Novel FBG sensors can maintain “the intense electrical, mechanical, and electromagnetic stresses of a fusion magnet’s environment.” The novel fiber optic technology supposes ultra-long fiber Bragg gratings of 9-millimeter located 1 mm apart. The FBG sensors operate as conventional long quasi-continuous systems.

Compared to standard systems, FBG sensors include such benefits as long grating length (meters instead of millimeters). Ultra-long FBGs allow for sensing simultaneously occurring temperature changes along their entire length. Thus, it is possible to determine fastly temperature variation, irrespective of the location of the heat source.

Additionally, it is possible to combine ultra-long FBGs and traditional FBGs to produce both spatial and temporal resolution. The fiber optic technology has been developed by a team of researchers from Switzerland. According to them, such a combination can be used on bigger cables.

These FBG sensors detect quickly and accurately even the smallest temperature changes under realistic operation conditions. Moreover, they demonstrate a better signal-to-noise ratio thanks to their high level of sensitivity and the opportunity to adjust the optical fiber response.

Thus, the fiber optic sensors locate quench events tens of seconds faster than voltage taps. Herewith, the application of FBG sensors for HTS magnets quenches detection is very potential. It allows for overcoming the current problem of  HTS coils from damage during quenches.

Finally, such a fiber optic technology plays a crucial role in compact fusion processes, where practical, high-field, high-temperature superconducting magnets are important. FBG sensors are still under development and need some improvements to be used in new applications.

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

Distributed Acoustic Sensing (DAS) for glaciated areas

DAS for glaciated area detectionNowadays scientists pay more attention to the process of Alpine microseismicity. The thing is that the sensing of seismic activity is important for studying landscape-shaping processes and predict dangerous mass movements. Nonetheless, the amount of modern fiber optic sensors is still low in Alpine regions. Therefore, distributed acoustic sensing (DAS) promotes solving the problem.

The application of advantageous fiber cables makes DAS technology very promising in seismic monitoring of glacier movements and natural hazards. Additionally, DAS technology has significantly changed the portability of seismic devices. This is why the performance of seismic monitoring in difficult-to-reach areas becomes more and more accessible.

It should be noted that the purpose of distributed acoustic sensing “focus on processes near the Earth’s surface rather than on traditional seismology subjects like the deeper crust and mantle.” DAS applies fiber optic sensors into which an interrogator enters a sequence of laser beam pulses. Herewith, fiber optic systems as distributed acoustic sensing are widely used in geophone chain deployments.

Fiber optic systems allow for sensing local earthquake signals, which are too weak to be recorded by conventional seismometers. Moreover, DAS enables the record of anthropogenic noise. Even though individual channels of distributed acoustic sensing have some disadvantages as a lower signal-to-noise ratio, they overcome seismometers. The thing is that there are a lot of unused fiber optic systems with unprecedented sensor coverage and density.

Novel DAS technology performs the records of microseismic signals and ambient noise in glacier areas. Compared to standard fiber optic systems, new distributed acoustic sensing offers important improvements in stick-slip event location and determines weak seismic waves. Herewith, the potential and utility of DAS systems are doubtless for sensing glacial processes.

According to scientists, DAS technology performs measuring seismogenic glacier flow and even small Alpine mass movements, for example, rockfalls. The benefits of distributed acoustic sensing include better limitation of static and dynamic properties of the glacier and its surroundings. The most significant thing is DAS technology provides precise arrival time measurements despite spatial averaging.

Finally, the advantages of DAS channels increase the location quality of stick-slip events significantly. The density of distributed acoustic sensing detects numerous reflections and extremely refracted waves. Herewith, spaced seismometer networks can not carry out it.

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