Jan 06 2010

Fiber Optic Sensors in Geosynthetics

Published by under OS Technology,Sensors

FBG sensors are incredibly versatile.  They’re used in tiny medical devices and on huge bridges.  Often FBG and other types of fiber optic sensors are chosen when many measurements are needed over a long distance and the environment is harsh.  A good example of this is the use of FOS in geosynthetic materials used to reinforce earthworks. 

TenCate Geosynthetics will soon release a new product called Tencate GeoDetect.  It’s a geotextile fabric with fiber optic sensors integrated onto it.  Wilson Harvie, Director of Global Business Development for GeoDetect, will lead this product rollout.  
Speaking recently to industry experts, Wilson said “Tencate GeoDetect is the first sensor enabled geotextile on the market.  Approximately five years ago TenCate began work on creating an “intelligent” geotextile.  We discovered a way to embed fiber optic lines onto a geotextile fabric without damaging the fiber.  Our initial work was with FBG technology but has now grown to encompass Brillouin and Raman technologies.  We are able to place multiple fiber optic lines on geotextile fabric up to 5.3 meters wide that provides all of the functionality of a geotextile; reinforcement, drainage, separation and filtration as well as provide a mechanism for data acquisition.  We have also found that in addition to the functionality of a geotextile, Tencate GeoDetect provides a “distributed anchoring” system which provides an excellent interface with the soil.  Our tests have shown that almost all of the strain that occurs in the earth structure is transferred to the fiber optic line.”  
Micron Optics is a key partner to TenCate Geosynthetics for interrogation equipment and fiber optic expertise.  Find product description sheets, case studies and technical papers on Tencate GeoDetect at http://www.tencate.com/smartsite.dws?id=8718

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Dec 14 2009

Structural Health Monitoring at Princeton University

Published by under General

When I speak to groups of engineers about FOS applications, typically fewer than 10% have even heard of optical sensors. The same is true for engineering students. But that is changing. More universities are finding clever ways to expose their students to FOS and other important technological tools.

The Structural Health Monitoring Lab at Princeton University is a shining example. Led by Professor Branko Glisic, the SHM lab at Princeton University has installed both FBG based and Brillioun FOS sensors on a signature pedestrian bridge on campus – Streicker Bridge. The goals include education and research activities — providing students with hands on installation experience, developing data reduction and analysis methods, showcasing the benefits and costs of such lifetime SHM systems, reducing maintenance costs for the bridge, and ultimately ensuring the bridge’s safe operation over decades of use.

The project is included in a Princeton University course on SHM. To the the best of my knowledge, it’s the first such course in the US on SHM for civil engineering students. Perhaps Professor Glisic’s students will be the first generation in the US to recognize and implement long term SHM systems as a means to reduce maintenance costs and improve safety of our nation’s bridges.

Professor Glisic recently joined the Princeton faculty following more than a decade of engineering and installing SHM systems commercially, and Micron Optics is proud to be the supplier of FBG interrogation system for Streicker Bridge project. Glisic says, “Fiber-optic sensing (FOS) technologies are used since the optical fibers feature high sensitivity, durability and long-term stability. The FBG long-gage sensors can monitor average strain, average shear strain, average curvature, deformed shape, and temperature in inhomogeneous materials such as concrete, and allows global structural monitoring in both static and high frequency dynamic mode. The BOTDA distributed sensors provide for average strain, integrity, and temperature monitoring. Each type sensor is interrogated with appropriate proven and reliable high-performance reading unit.”

Find out more about Branko Glisic, the SHM Lab and Princeton’s Streiker Bridge at: http://www.princeton.edu/~bglisic/StreickerBridge.html

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Oct 16 2009

os3150 – Rugged FBG Strain Sensor

Published by under General,Sensors

Micron Optics has just released the os3150, a rugged strain gage based on fiber Bragg grating (FBG) technology. Optimized for outdoor installations on steel structures, the os3150’s stainless steel carrier holds the FBG in tension and protects the fiber during installation.   Like the os3110 and os3120, installation is quick and easy.


In side by side comparisons with foil strain gages, the os3150 is equally sensitive and accurate, while providing for greater strain range and 100 times more fatigue life. The os3150 strain gage is qualified for use in harsh environments and delivers the many advantages inherent to all FBG based sensors.


For more details, view the datasheet on our website http://www.micronoptics.com/sensors_products.php







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Oct 07 2009


Published by under General,Software

A year ago I introduced ENLIGHT to you as it was first released. ENLIGHT provides an all-in-one software solution to configuring sensors connected to Micron Optics instruments, converting wavelengths to engineering units for hundreds or thousands of sensors, displaying data in charts, graphs or images, setting alarm limits and sending alerts, and saving data. Now I’m back with an update on the features of our next release which is coming soon.

In the past year we have worked to bring the software from an early Beta state to an optimized, faster running tool that’s ready for broad deployment. In response to customer feedback, our major focus has been on data management. For example, systems sampling hundreds of sensors at 1 kHz produce large amounts of data in a short time. New ENLIGHT features will allow files to be managed by size (e.g., once a file reaches 10MB, create a new data file), or by time (e.g., create a new file every day or hour). All files are stored in an automatically created directory structure organized by year, month, and day. Users will be able to choose what data to save, i.e., full spectrum traces, peak locations, FBG wavelengths or the calculated sensor values in engineering units.

Users will also be able to choose when data is saved. Data saving can be either continuous or triggered by an event such as a sensor moving into a warning or alarm condition. Users will select which sensors trigger data saving and then what data shall be saved. Data buffered prior to the event can also be included in the event file.

There will be more flexibility in manipulating data as well. Separate averaging controls will be available for spectra, peaks, FBGs, and sensor values. Another new feature will allow ENLIGHT to calculate the derivative of a sensor value so that the rate of change of a sensor value is known which is useful in fire detection applications.

Error handling will become more robust. Instrument diagnostic tools built into ENLIGHT will allow it to automatically recover to its normal operating state following a power interruption. Additionally, multiple copies of ENLIGHT will be able to run simultaneously on a single processor, thus managing more than one interrogator from a central PC.

For applications where custom user interfaces are required, users will be able to send commands to ENLIGHT via Ethernet to stream processed sensor data, zero sensor values, or retrieve saved data. In such cases, ENLIGHT acts as a signal conditioner simplifying integration of optical data with data streams from other systems.

The bottom line is that optical sensors are continuing to become easier to use. Better software, better instruments and better sensor packages are making this possible. Soon we’ll have more news on new sensor developments at Micron Optics and elsewhere.

A free download of ENLIGHT is available at http://micronoptics.com/sensing_software.php

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