Although there are many machineries and structures in which we are now living for carrying out a modern social operation, we will not be able to keep a life smoothly and safely unless functions or safety of these facilities be fully ascertained. Strain gages have developed and widened the scope of their application as one of the most fundamental means to confirm the degree of safety of machinery and structures we are using and also as the sensors to actually detect and measure strains and stress at the spot.The history of these strain gages is considerably long and old and the bonded type strain gages which we are currently using have been designed and schemed initially in 193.
8 by Simmons & Ruge in America. Strain gages are really indispensable means to detect strength and properties of metals, rubber, plastics, ceramics which we are using in our daily life.
