“…of the temperature profiles within and along the extrudate cross section, especially when the extrudate moves along the calibration/cooling system, is extremely difficult, requiring the use of thermocouples imbedded in the material, at different depths of the profile thickness, and moving with the profile (8). Profile surface temperatures between two consecutive calibrators are easier to monitor, but the quality of the measurements depends on the emissivity settings used in the noncontact infrared thermometers that are generally employed and also on the measuring depth, i.e., the thickness effectively reached by the radiation from the sensor (26). However, most of the temperature measurements reported concern pipes (1, 8,19,21,27) rather than profiles (20), and, even in this case, the data presented are insufficient for modeling purposes.…”