Fiber optic sensors provide immunity to EMI/RFI, magnetic fields, RF fields, microwaves, high voltage and resistance to radiation. They can also be incredibly small, lightweight, inherently safe, and operate interference-free over long distances. For any of these reasons, fiber optic sensors can operate where their electromechanical counterparts cannot perform (e.g., high voltage fields) or where dangerous to use (e.g., microwave ovens or explosive atmospheres). Fiber optic sensor products are commercially available that can measure Position, Limits, Force, Strain, Temperature, Acceleration, Vibration, and Vibration – interchangeably and with greater fidelity than their electronic counterparts.
Some examples of real-world, mission-critical applications where Fiber Optic Sensors are being routinely used:
- Non-metallic, MRI-invisible Rotary Encoders designed to operate within the high magnetic field of an MRI bore – enabling innovative medical products such as an MRI multimodal brain phantom and MRI-guided biopsy robot.
- Limit Switches, non-metallic and immune to high voltages, monitor the status of the high voltage bypass switches at each substation of the St Louis Metro system.
- Multi-axis Acceleration Sensors are used to monitor the vibration signature of large machinery, generators and electric train pantographs to ensure system health, optimal operation and safety.
- Emergency Stop sensor systems provide the means of remotely signaling operator emergencies working in hazardous areas, even when located miles away from the control center.
- Temperature sensors, intrinsically unaffected by microwaves and rf fields, are used by food, medical, chemical, industrial process and aerospace industries.
- The same Temperature probes, also immune to high voltages and e-fields, are used to monitor hotspots in substation transformer windings, bus bars, and generators to ensure proper operation, prevent damaging overloads, and maintain reliable operation of the power grid.
- Fiber Bragg Gratings (FBGs) provide multifunctional, multipoint temperature and strain measurement along a single fiber, to max of +800C or 20,000 microstrain. The applications are far-ranging, from monitoring structural health in buildings, aircraft and ships medical device development.
- Miniature FBG-based Force, Gripper and Grasping sensors for robotic and industrial automation applications. We will focus on this new class of products in the following presentation.
This overview of available FO sensor technologies, products and applications will provide the design engineer with real world examples that can be applied to his/her challenging projects and development ideas.
