The hardness is measured in a test known as a Durometer hardness test. It evaluates the hardness and durability of a material such as metal, plastic, glass, or rubber, when pressure is applied to it For example if the hardness of a glass pan on a car windshield is measured, we would want to know how likely it would be to crack over time without replacement. If the hardness of a steel spring is measured, we would know how much tighter the spring would have to be applied to provide adequate force Durometers may be calibrated according to ASTM D 2240 or ISO 868, a related method.
If the sample being tested is softer than the indenter, the pressure will be greater than the resistance of the sample. If the sample is harder than the indenter, the pressure will be less than the resistance of the sample. Also, the indenter will give a greater resistance force the greater the hardness of the material being measured. Durometer Type E The Durometer spring exerts a load on the mandrel of the hardness tester The hardness measurement is taken when the hardness tester makes contact with the top of the sample. With this type of hardness tester, a spring will exert a load on the hardness tester's mandrel. As the mandrel is pushed downward, the force exerted on the top of the sample is measured and converted to a hardness number. Type D Durometers The hardness process is similar to the Type E but some minor modifications are made to the spring and base of the mandrel. As in the Type E, this spring exerts a load on the mandrel of the hardness tester Type B Durometer The hardness process is similar to the Type A, except that a spring exerts its load on the base of the mandrel instead. d2c66b5586