Extrusion plastometers, also known as melt flow index testers are used to determine the melt mass flow rate (MFR) and melt volume flow rate (MVR) of a plastic melted mass. Measurement of the flow behavior of the melted material is used to compare different grades of the same polymer and provides an important parameter for quality assurance and incoming goods inspections, for material selection and the setup of processing machines by plastics processors. Demands on these melt flow indexers vary according to which plastics processing stage is involved.