A novel non-contact strain measurement technique utilising Rayleigh waves

Many devices that are used to convert a mechanical force or load to an electrical signal rely on the measurement of strain. The stress strain relationship, is one of the most fundamental concepts from the study of mechanics of materials and can be used to measure such diverse physical parameters as force, pressure, torque and acceleration. The author outlines the principle and background of a surface acoustic waves (Rayleigh waves) transducer and considers the use of such devices in a practical application. The measurement of torque in a rotating shaft is used to demonstrate many advantages of the technique