Thin-film pressure transmitter M7 SIL2

strain gaugevoltage output4-20 mA

Overview
The M7 SIL2 is a mercury-filled pressure transmitter engineered for high-temperature melt and process applications. It provides voltage output variants and a SIL2 certified option for Functional Safety systems in process industries such as polymer production. The device uses a fluid-filled hydraulic transmission to stabilize temperature effects and a thick-film strain-gauge sensing element to convert pressure into an electrical signal.

Main features

• Pressure ranges: from 0-17 to 0-2000 bar (0-250 to 0-30000 psi)
• Accuracy classes: < ±0.25% FS (H); < ±0.5% FS (M)
• Fluid-filled system (mercury) for temperature stability up to approx. 400 °C
• SIL2 certified variant for Functional Safety applications
• Standard mechanical threads: 1/2-20 UNF, M18x1.5 (other types on request)
• Standard diaphragm: 15-5 PH stainless steel with GTP+ coating; alternative diaphragms available

Description
The M7 series is built to measure pressure reliably in high-temperature media. Its hydraulic transmission with a fluid fill ensures the sensing element remains thermally stable even when media temperatures reach around 400 °C. A thick-film strain-gauge converts the transmitted pressure into a stable electrical output. The SIL2 certified variant is available for installations where functional safety integrity is required.

Additional notes / functions

• Autozero options: on-board magnetic autozero or external autozero
• Drift autocompensation available in SP version
• Flexible configuration: rigid or rigid+flexible stems, exposed capillary, thermocouple option
• Electrical options: multiple connector and terminal choices (e.g., 6-pin, 8-pin) and various voltage output ranges
• Special codes and custom configurations available on request

Characteristics / technical specifications

• Model: M7 SIL2
• Manufacturer: Gefran
• Measuring principle: hydraulic transmission with fluid-filled system
• Output signals: voltage variants (examples: 0.5–10.5 Vdc, 0.1–10.1 Vdc, 0.1–5.1 Vdc); 4–20 mA options available in M7 family
• Pressure ranges: typical examples B17U (17 bar) up to B02M (2000 bar); psi equivalents up to 30000 psi depending on configuration
• Accuracy classes: H (< ±0.25% FS), M (< ±0.5% FS)
• Operating media temperature capability: up to approx. 400 °C (designed for melt/high-temperature applications)
• Diaphragm materials/coatings: standard 15-5 PH stainless steel with GTP+ coating; 17-7 PH corrugated diaphragm with GTP+ for lower ranges
• Threads/examples: 1/2-20 UNF, M18x1.5 (others on request)
• Mounting/stem options: rigid rod, rigid + flexible rod, with thermocouple, exposed capillary
• Connector options: 6-pin, 8-pin or customer-specified connectors
• SIL2: certified variant available for Functional Safety applications
• Autozero: magnetic or external autozero options