3.3. Measuring method of hardness 3.3.1 Apparatus 3.3.1.1 Test machine The testing machine shall be able to indent the molded test piece between an loading plate which shall have a uniform relative motion, in the vertical direction, of 200mm/min and a supporting surface. The testing machine shall be able to measure the load with a precision of ±1% or ±1N or better, and to measure the thickness of the molded test piece under load with a precision of ±0.25mm or better.