Strain gauge pressure transmitter HKE

4-20 mAHARTthreaded

Overview
The HKE series are melt (high-temperature) pressure transmitters with HART communication and optional functional-safety levels (SIL2 / PLd). They use a sodium‑potassium (NaK) hydraulic transmission (liquid-filled) to transfer pressure from the process diaphragm to a strain-gauge sensing element, enabling stable measurements at media temperatures up to 538°C.

Main features

• Pressure ranges: 0-35 to 0-1000 bar (0-500 to 0-15000 psi)
• Accuracy classes: < ±0.25% FS (H); < ±0.5% FS (M)
• Hydraulic NaK transmission for thermal stability of the pressure signal (NaK = sodium-potassium)
• NaK fluid RoHS compliant and classified as GRAS-type safe substance
• Standard mechanical connections: 1/2-20 UNF, M18x1.5 (other threads on request)
• Autozero: on-board or external option
• Diaphragm materials/coatings for different temperature limits
• Output: analog 4-20 mA with HART protocol (digital overlay)

Detailed description

• Designed for melt and other high-temperature process applications where direct sensor exposure is limited by temperature
• Liquid-filled hydraulic transmission transmits process pressure through NaK to the sensing element, maintaining signal stability at elevated temperatures
• NaK fill volumes (example): HKE0 = 30 mm³; HKE1 / HKE2 / HKE3 = 40 mm³ (model dependent)
• Diaphragm options and temperature capabilities: Inconel 718 with GTP+ coating (up to 538°C / 1000°F); 15-5 PH with GTP+ (up to 400°C / 750°F); Hastelloy C276 (up to 300°C / 570°F); 17-7 PH corrugated diaphragm with GTP+ for ranges <100 bar / 1500 psi
• Stem material: 17-4 PH
• Typical electrical/mechanical options available to suit plant integration

Applications

• Pressure measurement in polymer extrusion and melt-processing
• High-temperature process lines in plastics, chemical and related industries
• Control and monitoring systems requiring HART communication and optional functional-safety rating

Technical specifications

• Model: HKE
• Pressure ranges: 0-35 … 0-1000 bar (also expressed in psi equivalents)
• Accuracy: < ±0.25% FS (H); < ±0.5% FS (M)
• Maximum media temperature: up to 538°C depending on diaphragm/coating
• Measurement principle: strain-gauge sensor with hydraulic (liquid-filled) pressure transmission
• Hydraulic fill: NaK (sodium-potassium), RoHS compliant; per-model fill volumes specified above
• Mechanical connections: 1/2-20 UNF, M18x1.5 (others on request)
• Output & communication: 4-20 mA with HART protocol
• Functions: on-board or external Autozero
• Stem material: 17-4 PH