Strain gauge pressure transmitter HMX

4-20 mAHARTM12 connector

Overview
The HMX series by Gefran are pressure transmitters for measuring melt and other high-temperature process pressures in fixed industrial installations and laboratory equipment. They feature a fluid-filled hydraulic pressure transmission, an optional mercury-filled construction, and are available with HART communication and versions certified for explosive atmospheres. The design allows measurement of media temperatures up to 400°C while converting pressure to an electrical signal via strain-gauge (Wheatstone bridge) technology.

Main features

• Pressure ranges: 0-17 to 0-2000 bar (0-250 to 0-30000 psi).
• Measurement principle: strain-gauge (Wheatstone bridge) with hydraulic (fluid-filled) transmission.
• Accuracy classes: < ±0.25% FS (H); < ±0.5% FS (M).
• Internal calibration signal: 80% FS.
• Ingress protection: IP65 (with 6-pin connector).
• Standard threads: 1/2-20 UNF, M18x1.5 (other threads on request).
• Diaphragms: 15-5 PH stainless steel with GTP+ coating; for ranges below 100 bar: 17-7 PH corrugated stainless steel with GTP+ coating.
• Output/communication: 4…20 mA; HART protocol available.

Product description

• Designed for melt and high-temperature process pressure measurement in extrusion and industrial production lines.
• Hydraulic fluid-filled transmission provides temperature stability at high media temperatures; mercury-filled option available for specific executions.
• Available configurations include rigid or flexible rods, thermocouple options, exposed capillary, flange mounting and various connector types.
• Versions with approvals for explosive atmospheres (ATEX, IECEx, etc.) and safety/performance levels (SIL2 / PLd) are available depending on model and configuration.

Notes

• Main applications: polymer processing (extrusion), melt pressure control, R&D laboratories and fixed industrial installations requiring high-temperature pressure measurement.
• Special executions and customized variants (mechanical lengths, connector types, calibration, approvals) can be supplied on request.

Technical specifications

• Model: HMX (Gefran).
• Pressure ranges: 0-17 … 0-2000 bar (0-250 … 0-30000 psi).
• Measurement principle: strain-gauge (Wheatstone bridge) with hydraulic (fluid-filled) transmission.
• Accuracy: < ±0.25% FS (H); < ±0.5% FS (M).
• Calibration: internal 80% FS signal.
• Ingress protection: IP65 (with 6-pin connector).
• Process temperature capability: up to 400°C (design for melt/high-temperature environments).
• Diaphragm materials/coatings: 15-5 PH stainless steel with GTP+; 17-7 PH corrugated stainless steel with GTP+ for specific lower ranges.
• Electrical outputs: 4…20 mA; HART (Smart HART) available; other outputs depending on configuration.
• Options: rigid/flexible rods, various connectors (6-pin, 8-pin, NPT cable), autozero options, SIL/PL options, different thread choices.
• Approvals: ATEX, IECEx, EAC, PAC, SIL2/PLd, KCs, NEPSI Ex, PESO (depending on version).