ABSTRACT
Diaphragms which become unstable and snap forward without any additional pressure are called snap-action diaphragms. A diaphragm can be made to "snap" if it is formed into a conical or spherical shape and pressure is applied to it from the convex side. Another requirement is that the diaphragm be made of thin material heat treated to high elastic properties. If properly designed, the diaphragm will snap with load and will return to its original position when the load is removed. In the analysis of diaphragm characteristics, the assumption has been made that the diaphragm median plane be perfectly straight and flat for a linear load-deflection relationship. There are applications, however, where the diaphragm median plane is deliberately made slightly convex or concave in order to obtain a specific desired result. In some applications a linear load-deflection relationship is not desired.
