Complete Extrusion Press Control Thermometry-a Reality at Last

摘要

Three new, non-contact, infrared thermometry systems have been developed for the measurement of extruded sections at the die exit and post quench together with a system specific to the mesurement of temperature profile ("taper") which may be used on moving billets immediately prior to press loading. The first two instruments utilize a multispectral detection system and complex algorithm, based upon experimentally determined knowledge of thewavelength-dependent, emissive behavior of "fresh" aluminum alloys to caluclate the true surface temperature. The third uses an enhancement technique to raise the effective emissivity, in the vicinity of the target spot, close to unity, and hence provide a high degree of independence from alloy changes and surface condition. All three systems are shown to have good accuracy (+-5degC or better), without the need for any elaborate set-up or continual recalibration. This asertion applies to the whole range of alloys and sections routinely encountered in commercial presses.