<P> Fiber optic sensing can be employed to measure strain along an optical fiber . Measurements can be distributed along the fiber, or taken at predetermined points on the fiber . The 2010 America's Cup boats Alinghi 5 and USA - 17 both employ embedded sensors of this type . </P> <P> Microscale strain gauges are widely used in microelectromechanical systems (MEMS) to measure strains such as those induced by force, acceleration, pressure or sound . As example, airbags in cars are often triggered with MEMS accelerometers . As alternative to piezo - resistant strain gauges, integrated optical ring resonators may be used to measure strain in Micro-Opto - Electro - Mechanical Systems (MOEMS). </P> <P> Capacitive strain gauges use a variable capacitor to indicate the level of mechanical deformation . </P> <P> Vibrating wire strain gauges are used in geotechnical and civil engineering applications . The gauge consists of a vibrating, tensioned wire . The strain is calculated by measuring the resonant frequency of the wire (an increase in tension increases the resonant frequency). </P>

Semiconductor strain gauges are routinely used in transmitters for