The sensor solution allows the readily available POF to be used as a high-precision strain sensor comparable to current fiber optic Bragg grating (FBG) strain sensors for a wide range of applications including wind blade load management in wind turbines and structural health monitoring of many other structures.
Key features of the Avago OPI sensor
: • Uses polymer optical fiber as the sensing element, which is mass-produced and cost-effective
• Offers a high yield strength (>5%) → wide dynamic range
• Easy to use and install
• High sensitivity and accuracy
• EMI/EMC immunity
• Robust sensor electronics for sensor indication implementations
The optical sensor uses the POF to form a "meandering path" sensor network, allowing a single fiber to form multiple circumscribed loops within a closed area (see figure). These loops, under tension, alter the phase of an optical signal injected into the fiber. A separate, unstressed reference loop surrounds the meandering path and is used to compare the reference signal with the tension signal. The phase difference between the two signals can then be converted into a tension measurement. The reference fiber simultaneously provides temperature compensation. Because the sensor network contains only optical fibers, it is immune to EMI and EMC interference and is completely electrically isolated from the rest of the system.
“Avago Technologies has supplied a large number of POF communication cables and modules for industrial networking and data communication applications, accumulating considerable experience in both markets,” explains Martin Weigert, General Manager of Avago’s Optical Fiber Production division. Leveraging this experience, the development of industrial optical sensor technology is a natural extension of the company’s core capabilities, enabling it to target a rapidly growing market, Weigert continued. “Our patented optical phase interrogation method has allowed us to offer a disruptive strain sensor solution using POF: a viable alternative to conventional electrical and optical strain sensor technologies for numerous applications.”
Avago is implementing a range of applications related to the wind energy industry and is currently installing sensors on a conceptual multi-megawatt turbine for both wind blades and load monitoring towers. In this market, the technology demonstrates its full potential by offering a reliable alternative to conventional strain measurement technologies.
Avago has assembled a development kit to assist designers in the testing and evaluation of sensor technology. The kit consists of a length of polymer optical fiber, an optical phase interrogator, and the necessary documentation to create a strain sensor with the fiber and evaluate the results. The development kit will be available starting in January 2014.
currently
evaluating the implementation of its technology for a range of applications. For a pre-launch evaluation, please contact your local Avago sales representative regarding the technology and the availability of the evaluation kit.
