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Measurement of strain with strain gauges and FBG strain sensors

The relationship between stress put on a material and the resulting deformation is defined by Hooke’s Law that has been around since 1678. Different techniques and technologies have been used to measure the law over different periods of time. In the past mechanical strain gauges have been used to measure strain applied to a material. The first strain gauges were analog. Some of these devices, like springs and levers, are still used today, but they are not accurate enough as the strain applied to the material would have to be quite high for the device to register it. Strain gauges have a number of disadvantages, one of them being the need to be clamped firmly so the device didn’t move which causes an inaccurate reading.

The next step in strain measurement techniques were resistive strain gauges, the most common of which are foil resistive gauges. These devices are better than the previous model as they are sensitive, accurate, easier to produce. However, the lack of foil elasticity poses limitations on the device, for example, resistive strain gauges cannot be used for ductile materials. To overcome this downside conductive material can be added to elastomers for a stretchier gauge.

The best solution that has been developed so far for strain measurements are fiber Bragg grating strain sensors. They are still catching on as their initial price and lack of awareness slowed their adoption among industry professionals. However, the price of FBG strain sensors is dropping every year which is tied with the level of development of fiber optic technology.

The low price of FBG sensors makes them available for different applications, some of which include automotive, medical, aerospace, and energy markets. FBG strain sensors have been found to be useful in aerospace applications where they are used to determine wing loading while providing accurate fuel readings. Civil engineers utilize FBG sensors for structural health monitoring. The operational life of vehicles can be determined with the use of FBG sensors that are widely utilized by automotive designers. FBG strain sensors are lighter, easier to install, and less expensive than strain gauges.

Optromix, Inc. is a U.S. manufacturer of innovative fiber optic products for the global market, based in Cambridge, MA. Our team always strives to provide the most technologically advanced fiber optic solutions for our clients.

Optromix is a fast-growing vendor of fiber Bragg grating (FBG) products line: fiber Bragg grating sensors, FBG interrogators, and multiplexers, Distributed Temperature Sensing (DTS) systems. We create and supply a broad variety of top-notch fiber optic solutions for the monitoring of various facilities all over the world.

If you are interested in Optromix FBG strain sensors, please contact us at info@optromix.com