E&H FMD77 pressure transmitter

E&H FMD77 pressure transmitter

1. Product Overview

The E&H FMD77 pressure transmitter features a piezoresistive metallic sensor with welded metal diaphragm and capillary diaphragm seal system, delivering exceptional accuracy, long-term stability, and overload resistance. The FMD77-DCC7HCDDNFAA belongs to the Deltabar S platform, a modular transmitter family that supports seamless integration with HART, PROFIBUS PA, and FOUNDATION Fieldbus communication protocols.

A four-line digital display and three-key pushbutton interface enable straightforward commissioning and operation, while the integrated HistoROM data module facilitates efficient management of process and device parameters. The device is designed according to IEC 61508 and certified for functional safety applications up to SIL3.–31

The FMD77 uses a one-sided diaphragm seal or diaphragm seals on both sides with a capillary on the low-pressure side, making it particularly suitable for applications where the process media cannot directly contact the measuring cell.-31

2. Complete Technical Specifications

Specifications source: Endress+Hauser Deltabar S technical documentation.-10-31

3. Order Code Breakdown: FMD77-DCC7HCDDNFAA

The FMD77-DCC7HCDDNFAA represents a fully configured differential pressure transmitter with specific selections for approval, output, housing, nominal range, calibration, and process connection. Below is the decoded configuration:

This configuration is well-suited for level measurement applications requiring flameproof approval, 4-20 mA HART communication, local display, and 316L wetted parts for compatibility with a wide range of process media. The FMD77-DCC7HCDDNFAA features Ex d flameproof enclosure, making it suitable for installation in hazardous areas with combustible gases or dusts.

4. Performance Characteristics

The E&H FMD77 pressure transmitter achieves a reference accuracy of up to 0.05% of span when ordered with the Platinum option, making it suitable for high-precision level and flow measurement applications. The long-term stability of less than 0.05% of URL per year ensures sustained measurement reliability over extended operational periods.

For dynamic response, the dead time of the FMD77 is typically under 100 milliseconds for the HART output variant, with adjustable damping from 0 to 999 seconds to accommodate process noise and pulsation. The device supports a turn-down ratio of 100:1, allowing a single transmitter to cover a wide range of operating conditions without recalibration.

The TempC membrane technology incorporated in the FMD77-DCC7HCDDNFAA diaphragm seal system minimizes temperature effects and ensures short recovery times, delivering stable measurements even under fluctuating thermal conditions.-2

5. Communication and Integration

The E&H FMD77 pressure transmitter supports three primary communication protocols:

4-20 mA HART — Universal analog output with digital HART communication for parameterization and diagnostics. Supply voltage range: 10.5–45 V DC (non-Ex).

PROFIBUS PA — Digital fieldbus communication compliant with IEC 61158-2, enabling integration into process automation systems. Supply: 9–32 V DC.

FOUNDATION Fieldbus — Same electrical layer as PROFIBUS PA, supporting device description and function block-based control strategies.

The modular design of the FMD77-DCC7HCDDNFAA allows field replacement of sensor, electronics, or display modules without recalibration, reducing downtime and maintenance costs. The device can be integrated into existing control systems using standard DD (Device Description) and Cff (Capability File) files.-

6. Applications

The E&H FMD77 pressure transmitter is deployed in the following primary applications:

Level measurement — Continuous level, volume, or mass measurement in liquids in both open and closed containers. The FMD77 is particularly well-suited for this application as it is ready for calibration immediately after opening a shut-off valve.–3

Flow measurement — Volume or mass flow measurement in conjunction with differential pressure primary elements (orifice plates, pitot tubes, Venturi tubes) for gases, vapors, and liquids.-

Differential pressure monitoring — Filter monitoring, pump differential pressure surveillance, and heat exchanger pressure drop tracking.-3

High-temperature applications — When equipped with diaphragm seal systems, the FMD77-DCC7HCDDNFAA can support process temperatures up to 400°C (752°F).

Hygienic applications — When fitted with appropriate hygienic connections and seals, the E&H FMD77 pressure transmitter can be used in food, beverage, and pharmaceutical industries.

7. Safety and Compliance

The E&H FMD77 pressure transmitter is designed according to IEC 61508 and certified by TÜV SÜD for functional safety applications up to SIL3. Key safety features include:

Gas-tight feedthrough providing a secondary process barrier

Continuous function monitoring from measuring cell to electronics

Self-diagnostic functions for early fault detection

Overload resistance up to 160 bar with function-monitored design

Ex d flameproof enclosure (as configured in FMD77-DCC7HCDDNFAA)

International explosion protection approvals include ATEX, FM, CSA, IECEx, INMETRO, NEPSI, and EAC, ensuring global deployment capability in hazardous areas.-25 Additional certifications include WHG overfill prevention, GL marine approvals, NACE MR0175/MR0103 for sour service environments, and EN10204-3.1 material certification.-31

8. Ordering Information

For additional order code variants or custom configurations, please consult the official Endress+Hauser product configurator or contact our technical sales team with your specific application requirements. The complete technical documentation, including Technical Information TI00382P/00/EN and Operating Instructions BA00294P/BA00296P, is available for download from the Endress+Hauser website.