ABSTRACT
This chapter begins with a review of the fundamental definitions of strain and ways it can be measured. This is followed by a review of the many types of strain sensors and their application, and sources for strain sensors and signal conditioners. Next, a more detailed look is taken at operating principles of various strain measurement techniques and the associated signal conditioning. These include piezoresistive gages (foil or wire strain gages and semiconductor strain gages), piezoelectric gages (polyvinylidene fluoride film and quartz), fiber optic gages, bircfringent films and materials, and Moire grids. The longitudinal strain sensitivity is given as sensor output per unit longitudinal strain in the sensor direction. This is divided by the viewing length to obtain the strain resolution. Strain gages are mounted to test specimens with adhesives using a procedure that is suitable for bonding most types of strain sensors.
