Pressure pick-up for melts, abrasive media and solid beds

摘要

The invention relates to a pressure pick-up for melts, abrasive media and solid beds, in particular for use in plastics-processing machines. The pressure measurement is performed by a metal plate, the thickness of which is designed for the pressure range to be measured. The deformation of the metal plate causes a volume displacement to take place behind it, which is transmitted by a liquid to the measuring element. Since the metal plate takes the forces of the pressure, the liquid pressure is relatively low. Temperature influences which are caused by thermal expansions are compensated by the liquid and the surrounding housing thermally expanding in the same way. This is achieved by a liquid-solid mixture. Due to the stable form of the metal plate, the pressure pick-up can be used both in hot polymer melts and in abrasive media and solid beds, such as plastics powders and granules.