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Datasheet summary

Deltabar S FMD77

Engineering summary from PDF text extraction for Deltabar S FMD77. Verify every value with the OEM datasheet.

Summary

Product identification

The Deltabar S FMD77 is a differential pressure transmitter with metallic measuring cells. It is designed for applications involving gases, vapors, and liquids.

Applications

Flow measurement (volume flow or mass flow) in conjunction with primary devices.
Level, volume, or mass measurements in liquids.
High process temperatures up to 400 °C (752 °F) are possible with a diaphragm seal mount.
Differential pressure monitoring, for example, of filters and pumps.

Benefits

High reproducibility and long-term stability.
High reference accuracy up to 0.035 %.
Turn down ratio up to 100:1, higher on request.
Suitable for flow and differential pressure monitoring up to SIL3, certified to IEC 61508.
High operational safety due to function monitoring from the measuring cell to the electronics.
Patented TempC process membrane for diaphragm seals minimizes measurement error from environmental and process temperature effects.
Easy electronics replacement with HistoROM®/M-DAT.
Cost-effective installation with capillary on the low-pressure side for the FMD77.

Measuring principle

The device utilizes metallic membranes that are deflected by acting pressures. A fill fluid transfers this pressure to a resistance bridge in semiconductor technology. The resulting change in bridge output voltage is measured and processed.

Standard operating pressures range from 160 bar (2400 psi) up to 420 bar (6300 psi).
Features high long-term stability and very high single-sided overload resistance.

Communication protocol

4 to 20 mA with HART communication protocol.
PROFIBUS PA.
FOUNDATION Fieldbus.

Input

Measured variable

Measured process variables: Differential pressure, pressure.
Calculated process variables: Flow rate (volume flow or mass flow), absolute pressure, gauge pressure, level (level, volume, or mass).

Measuring range

FMD77, FMD78, PMD75:

Option PN 160 / 16 MPa / 2400 psi:
- Measuring cell range (LRL to URL): 10 mbar to 160 bar (0.15 psi to 2400 psi).
- Smallest calibratable span: 0.25 mbar (0.00375 psi) for FMD77/FMD78, 1 mbar (0.015 psi) for PMD75.
- Maximum working pressure (MWP) on both sides: 160 bar (2400 psi).
- Overload pressure limit (OPL) on one side: 160 bar (2400 psi).
- Minimum static pressure: 0.1 mbarabs (0.0015 psiabs).
Option PN 420 / 42 MPa / 6300 psi (PMD75 only):
- Measuring cell range (LRL to URL): 100 mbar to 420 bar (1.5 psi to 6300 psi).
- Smallest calibratable span: 1/5 mbar (0.015/0.075 psi).
- Maximum working pressure (MWP) on both sides: 420 bar (6300 psi).
- Overload pressure limit (OPL) on one side: 420 bar (6300 psi).
- Minimum static pressure: 0.1 mbarabs (0.0015 psiabs).

PMD75 (Gauge or Absolute):

Option 160 bar (2400 psi) gauge:
- Measuring range (LRL to URL): -1 to 160 bar (-15 to 2400 psi).
- Smallest calibratable span: 40 bar (600 psi).
- MWP: 160 bar (2400 psi).
- OPL: 240 bar (3600 psi).
Option 160 bar (2400 psi) absolute:
- Measuring range (LRL to URL): 0 to 160 bar (0 to 2400 psi).
- Smallest calibratable span: 4 bar (60 psi).
- MWP: 160 bar (2400 psi).
- OPL: 240 bar (3600 psi).
Option 250 bar (3750 psi) gauge:
- Measuring range (LRL to URL): -1 to 250 bar (-15 to 3750 psi).
- Smallest calibratable span: 40 bar (600 psi).
- MWP: 250 bar (3750 psi).
- OPL: 375 bar (5625 psi).
Option 250 bar (3750 psi) absolute:
- Measuring range (LRL to URL): 0 to 250 bar (0 to 3750 psi).
- Smallest calibratable span: 4 bar (60 psi).
- MWP: 250 bar (3750 psi).
- OPL: 375 bar (5625 psi).

Output

Output signal

4 to 20 mA with superimposed digital communication protocol HART, 2-wire.
Digital communication signal PROFIBUS PA (Profile 3.0), 2-wire.
Digital communication signal FOUNDATION Fieldbus, 2-wire.

Signal range

4 to 20 mA standard range.
3.8 mA to 20.5 mA extended range.

Signal on alarm

4 to 20 mA HART: As per NAMUR NE43. Max. alarm settable from 21 to 23 mA (factory: 22 mA), Hold measured value, Min. alarm: 3.6 mA.
PROFIBUS PA: As per NAMUR NE43. Options include Last Valid Out Value, Fail Safe Value, Status bad.
FOUNDATION Fieldbus: As per NAMUR NE43. Options include Last Good Value, Fail Safe Value, Wrong Value.

Load

4 to 20 mA HART: Maximum load resistance R_Lmax depends on supply voltage U_0. See the official PDF for load diagrams and details.

Damping

Adjustable via onsite display, handheld terminal, or PC from 0 to 999 s.
Can also be set via DIP switch for HART and PROFIBUS PA.
Factory setting: 2 s.

Firmware version

Various firmware versions are available, supporting HART 5, HART 7, PROFIBUS PA, and FOUNDATION Fieldbus.

Protocol-specific data HART

Manufacturer ID: 17 (11 hex).
Device type ID: 23 (17 hex).
HART specification: 5 or 7.
Supported functions include Burst mode, Additional transmitter status, Device locking, and Alternative measuring modes.

Wireless HART data

Minimum starting voltage: 11.5 V (default) or 10.5 V.
Start-up current: 12 mA.
Starting time: 10 s.

Protocol-specific data PROFIBUS PA

Manufacturer ID: 17 (11 hex).
Identification number: 1542 hex.
Profile version: 3.0 or 3.02.
GSD revision: 4 or 5.

Protocol-specific data FOUNDATION Fieldbus

Manufacturer ID: 452B48 hex.
Device type: 1009 hex.
Device revision: 6 or 7.
DD revision: 2 or 3.
CFF revision: 1 or 4.
ITK version: 5.0 or 6.01.
Link-Master (LAS) capable: Yes.

Energy supply

Supply voltage ranges vary depending on the electronic version and communication protocol. For 4 to 20 mA HART, it is between 10.5/11.5 V DC and 45 V DC. For PROFIBUS PA and FOUNDATION Fieldbus, it is typically 9 to 32 V DC for non-hazardous areas and specific values for Ex ia installations.
Current consumption: PROFIBUS PA is 13 mA ±1 mA; FOUNDATION Fieldbus is 15.5 mA ±1 mA.

Electrical connection

Terminals for supply voltage and ground are suitable for wire sizes 0.5 to 2.5 mm² (20 to 14 AWG).
Cable entries include M20x1.5 for standard and certain hazardous area approvals, and metal M20x1.5 (Ex e) for other hazardous area approvals.
Connectors available include Harting plug Han7D, M12 plug, and 7/8" plug.
Recommended cable specifications for HART, PROFIBUS PA, and FOUNDATION Fieldbus involve twisted, shielded twin-core cables.

Start-up current

12 mA.

Residual ripple

Up to ±5% residual ripple is acceptable for the 4 to 20 mA signal without influencing its accuracy, within the permitted voltage range.

Overvoltage protection

Optional for HART, PROFIBUS PA, and FOUNDATION Fieldbus.
Nominal functioning DC voltage: 600 V.
Nominal discharge current: 10 kA.
Devices with integrated overvoltage protection must be grounded.

Performance characteristics

Response time

HART: Acyclic: min. 330 ms, Cyclic (burst): min. 160 ms.
PROFIBUS PA: Acyclic: approx. 60-70 ms, Cyclic: approx. 10-13 ms.
FOUNDATION Fieldbus: Acyclic: typically 100 ms, Cyclic: max. 20 ms.

Reference operating conditions

As per IEC 62828-2 / IEC 60770.
Ambient temperature: +22 to +28 °C (+72 to +82 °F).
Humidity: 5 to 80 % RH ± 5 %.
Atmospheric pressure: 860 to 1060 mbar.
Position of measuring cell: horizontal ±1°.

Total performance

The total performance is a combination of reference accuracy, ambient temperature effect, and static pressure effect. Detailed calculations are available via the Endress+Hauser Applicator.