Rheometry has been widely used in many industrial applications, especially for processed material experiencing the relatively high viscous state, such as plastics/rubber processing, coating and food processing. There are four main purpose of rheometry for the industrial application: (1) material characterization, (2) quality control, (3) explanation of physical (processing) phenomena and (4) generating data for design of processing equipment. There are many types of rheometers. Among those the rotational and the capillary rheometers are most widely used in industries and academia for the measuring shear rate dependent viscosity-viscosity function-of the high viscous materials such as molten polymer. The dominant usage of these rheometers is due to the well-developed theory behind and the relatively easy of conducting the experiment. However in some cases the measurement using these rheometers exhibit unexpected erroneous results due to the complexity of the testing materials, which are high-filler loaded materials, rubbery materials, thermally sensitive materials and hygroscopic materials. Novel device has been developed in Polymer Manufacturing Innovation Institute- PMII- based on well-defined single screw extrusion theory. The screw rheometer -SR- reveals many advantages such as self-plasticating, self-deaeration, free-from-clogging, mixing-during-measuring, fast-measuring-time and so on. This work elucidates the non-newtonian correction of viscosity calculation and some application results.