4.1 This testing is performed to determine the electrical contact reliability under switching conditions and the physical changes caused by mechanical actuation of the switch assembly in the environments in which the assemblies operate. Evidence of deterioration, that is, cracking of substrate, domes both metal and polyester, ink delamination, etc., resulting from this test can at times be determined by visual examination. However, the effects may be more readily ascertained by measurements made prior to, during, and after exposure. Total circuit resistance, force-displacement, dielectric strength, insulation resistance, and capacitance are types of measurements that show the deleterious effects due to exposure.