The hardness of rubber is connected to its elastic modulus. However, a nonlinear relationship between these characteristics is a common disadvantage of all conventional methods of measuring hardness of rubbers. That is, hardness values do not give adequate information about the real rigidity of rubbers and rubber products. Low sensitivity methods for measuring hardness of hard rubbers is due to the same circumstances. These problems can be solved by applying a method based on measuring force when impressing an indenter to a fixed depth. The method can be realised by using special equipment or a tensile-testing machine.