The HWX4 series of Gefran, are pressure transmitters for using in High temperature environment and specifically designed for melt pressure measurement and available to be used in large-scale fixed installations or in large-scale stationary industrial tools rather than laboratory equipments. The HWX4 series of Gefran are flanged pressure transmitters with HART communication protocol for using in high temperature environment with explosive atmosphere presence. The main characteristic of this series is the capability to read temperature of the media up to 315°C. The constructive principle is based on the hydraulic trasmission of the pressure. The fluid-filled system assures the temperature stability. The physical measure is transformed in a electrical measure by means of strain-gauge technology. The SIL2 and PL d approvals make the product suitable for use in the Functional Safety applications, particularly in the process plants for the production of polymers, where it is an essential requirement.