Rheonik RHE28 Universal Mount Mass Flow Transmitter

A light, wall-mounted transmitter for remote Coriolis sensors

The Rheonik RHE28 is the field and wall mount member of the transmitter range, used for general process flow, batching and mixing, feed stock transfers, custody transfer and allocation metering. At 2.4 kg in an epoxy coated aluminum case it hangs on a wall, pipe or hook near the sensor and connects through cage-clamp terminals, with cable available up to 100 m to a remote Rheonik sensor.

The unit is a multifunction device: mass flow, volume, density and temperature in selectable units, with positive, negative and net totalizers for volume and mass.

Datasheet features

• Operates RHM sensors in hazardous areas, while the transmitter itself fits Zone 2 / Div. 2 locations.
• Two configurable pulse/frequency/status outputs, two analog outputs, two status outputs and two digital inputs.
• Analog input for pressure or density, and advanced functions such as Net Oil, Brix/Baume, percent solids, concentration and API standard volume.
• Custody transfer version with lockout switch and seal point.
• Quick service through USB; power consumption below 5 W.

Technical specification

How the order code is built

Housing E1 is the standard IP65 / NEMA 4 case for -20 to +60 C, while E2 is the endurance IP66 / NEMA 4 version for -40 to +60 C. Power codes are D1 (12-24 VDC), A1 (100-240 VAC) and U1 (both). I/O codes are S1 (one 4-20 mA, two digital outputs, one input and Modbus), S2 (two analog outputs), SH (adds HART) and CH (adds HART and the analog input). Software packages are SO, DO, AF, GV and CT. Hazardous area codes: AS (ATEX/IECEx associated equipment, [Ex ia Ga] IIC), AB (Zone 2, Ex nA IIB, excluding hydrogen and acetylene), A2 (Zone 2, IIC including hydrogen and acetylene), CS (cCSAus Class I), CB (Class I Div. 2) and C2 (Class I Div. 2 including hydrogen and acetylene).

Software packages in plain terms

SO is the standard operation system: direct mass flow, temperature, fixed and calculated density, standardized gas volume, batch control and password protection. DO adds measured density, which needs an RHM density calibration, plus Brix and Baume units. AF adds the Assurance Factor, zero point history, data recording, a PID controller and partly filled pipe management. GV adds API standard density and volume, Net Oil and concentration. CT adds the hardware lock switch for sealing. RHECom Free is available at no cost; the Pro and Pro+ versions add trending and a simulator.

Installation considerations

Choose between the standard M16/M20 glands or 1/2 in NPT entries (option E1). Because the transmitter and sensor must have matching certification, match the zone rating of the RHM sensor to the RHE28 code. The Assurance Factor value can colour the display white, amber, blue or red for operation normal, not optimal, at limit or measurement failure.

Compared with other RHE models

The RHE28 sits between the compact RHE26 and the explosion-proof RHE21: it adds AC power, a second analog output, HART and an analog input compared with the RHE26, but its aluminum case is rated for ordinary locations and Zone 2 or Div. 2, not for Ex d use in Zone 1. For installation of the transmitter itself in Zone 1 or Div. 1, look at the Ex d housings of the RHE21.

Typical use in the Gulf

Skid-mounted chemical dosing, fuel and lube oil batching, and tanker loading arms commonly need a compact, wall-mounted transmitter that sits away from the pipe, which suits a Zone 2 plant area or a safe-area control room.

Selection and installation notes

A mass flow transmitter must match the sensor it is connected to, so confirm the sensor model, the cable length, the supply voltage, the output types and the area classification before ordering. Keep the signal cable away from power cables, ground the shield as described in the manual, protect the housing from direct heat and water ingress and record the calibration factors and zero values at commissioning. Use the correct cable glands and seals, particularly in hazardous areas.

Information needed for a quotation

Send the full model code, the quantity, the delivery location in Oman or the GCC, the intended use and any accessories needed, so that the complete package can be quoted together.

Documents and supply information

The manufacturer data sheet is attached to this page and should be read together with the project specification and the site risk assessment before a purchase is confirmed. Ratings, standards and dimensions are quoted as printed on that sheet. Lead time, stock position and certificates available with the shipment are confirmed in the quotation, and we supply to Oman and the wider GCC region for industrial, utility and building services projects.

Related items

RHM sensors, mounting hardware and cables are listed in the sensor datasheets. See flow and process measurement for related equipment. Send the sensor model, zone and I/O needs and we will quote; confirm the full part number before ordering.

Related Rheonik products: Rheonik RHE21 Ex d Field Mount Mass Flow Transmitter, Rheonik RHE42 All-Digital Field Mount Mass Flow Transmitter, Rheonik RHE46 Economic DIN Rail Mass Flow Transmitter, Rheonik RHM20 Coriolis Mass Flow Meter Sensor 480 kg/min, Rheonik RHM06 Coriolis Mass Flow Meter Sensor 36 kg/min and Rheonik RHM40 Coriolis Mass Flow Meter Sensor 1500 kg/min.