Sensitive sensors for safer bridges and wind turbines

Sensitive sensors for safer bridges and wind turbines

First Sensor is launching a new generation of high-accuracy capacitive silicon inertial sensors aimed at applications in the fast-growing market of smart structural monitoring. The new sensors offer the resolution and low noise density required for recording vibrations or changes of inclination in wind turbines, bridges and high-rise buildings, thereby uncovering risks in the structure or material at an early stage. Integrated in smart solutions, these highly cost-effective sensors ensure the safety of structures both in everyday operation and following events such as storms, earthquakes, large loads or changes in the foundations. The sensors for measuring tilt, acceleration and vibration consist of a silicon sensor element made in accordance with a patented micromechanical process (HARMS, AIM) in conjunction with a signal-processing ASIC in a hermetically sealed SMD housing.

Ensuring the safety of exposed structures such as bridges and wind turbines still usually involves time-consuming visits and inspections. Remote structural monitoring using smart sensors creates an attractive growth market because these technologies can be used to continuously monitor and analyze the condition and loading of buildings, bridges and wind turbines. Repairs and safety measures can be organized much more effectively, while potential risks following extraordinary events such as earthquakes, storms and landslides can be better assessed.

To perform these tasks, the inertial sensors from First Sensor achieve resolutions of 10 µg or 0.0005° (2 arc seconds) depending on the bandwidth. In addition to standard models, First Sensor also develops modules that are mechanically and electrically adapted for special customer applications. To support projects and developers, evaluation kits are available for the quick and easy evaluation and configuration of the sensors.

Patented technology

The high-accuracy inertial sensors from First Sensor detect even the smallest changes in position or acceleration. They offer not only superior performance features, but also an outstanding price–performance ratio compared with existing solutions. The monocrystalline silicon microstructures with a high aspect ratio (HARMS) ensure minimal cross sensitivities, high signal-to-noise ratios and exceptional temperature stability. Furthermore, the patented AIM (air-gap-insulated microstructures) technology minimizes parasitic capacitances by insulating the components with an air gap. As inclination sensors with measurement ranges of ±30°, the sensors achieve a noise density of less than 0.0004°/√Hz and resolutions of less than 0.0015° at a measurement frequency of 10 Hz. When used as acceleration sensors, the MEMS from First Sensor offer measurement ranges of ±3 g, ±8 g and ±15 g and achieve a noise density of less than 30 µg/√Hz and resolutions of less than 40 to 95 µg at a measurement frequency of 10 Hz.

Further product information can be found here. In the manufacturer’s blog, the function and precision of the MEMS sensors are clearly explained; you can also ask about free webinars.