Rosemount 8732EM Field Mount Magnetic Flow Transmitter

Rosemount 8732EM field-mount magnetic flow transmitter and its model code

The Rosemount 8732EM is the field-mount transmitter of the Rosemount 8700M magnetic flow meter platform. It drives the coils of an electromagnetic sensor, reads the electrode signal and turns it into a flow value that can leave the instrument as 4–20 mA with HART, a scalable pulse, FOUNDATION Fieldbus, Modbus RS-485 or EtherNet/IP. It can be bolted straight onto a sensor (integral mount) or placed on a pipe stand or wall with a cable kit (remote mount). Seven Star LLC supplies 8732EM transmitters and matching sensors in Oman and the GCC as an independent supplier in Muscat.

The ordering string is built from fixed positions. The manufacturer’s example is 8732EM T 1 A 1 K5 DA1 AX M4 C1 GM V2 Q4 HR7 RT05, which reads as follows.

8732EM technical specifications

How the 8732EM measures flow

Magnetic flow metering follows Faraday’s law: a conductive liquid crossing a magnetic field generates a voltage proportional to its velocity. The transmitter energises the sensor coils with a 500 mA drive current, picks up the small electrode voltage and converts it into a flow rate using the calibration number stamped on the sensor nameplate. Because no part of the sensor protrudes into the stream, there is no pressure drop beyond the pipe bore itself, and the reading does not depend on density, viscosity or temperature of the liquid, provided the liquid is conductive enough.

The basic diagnostics are built in: ground and wiring fault, tunable empty pipe, reverse flow, coil circuit fault, electronics temperature and transmitter self-test. Option DA1 adds high process noise detection and electrode coating detection, while DA2 adds SMART Meter Verification, which can be run on command or continuously, and a 4–20 mA loop verification with HART output. Three independent totalizers, damping up to 256 s and a low flow cut-off adjustable between 0.01 and 11.7 m/s complete the signal conditioning.

Where the 8732EM fits and related Rosemount parts

The 8732EM is the field-mount member of the platform; the wall-mounted partner is the 8712EM with a 15-button keypad, and the sensors are the 8705-M flanged, 8711-M/L wafer and 8721 hygienic types. In an integral installation the sensor and transmitter are ordered together and the sensor calibration number is already matched. In a remote installation the transmitter is connected through a coil cable and an electrode cable, or through a single combination cable, supplied as a kit (RTxx, RHxx, RCxx or RSxx) with lengths from 10 ft up to 500 ft. Related catalog items on our site include the 8700 series magnetic flowmeter, the 8750W sensor family and the Rosemount 8800D vortex meter for non-conductive or steam duties.

Selection and ordering checklist for 8732EM

• Confirm the liquid is conductive, 5 µS/cm or more; a hydrocarbon or distilled product needs a different technology.
• Choose integral or remote mount; remote mount is needed if the sensor will be submerged (IP68 requires a remote transmitter) or sits in a hot or vibrating location.
• Match the supply: AC mains, 24 Vdc, or the low-power DC version, which limits the line size to 10 in. and reduces accuracy to 1% of rate.
• Pick the output the control system reads: HART, FOUNDATION Fieldbus, Modbus RS-485 or EtherNet/IP. EtherNet/IP is not available with hazardous-area or two-entry conduit codes.
• Select the hazardous-area code (for example K5 explosion-proof, K1 ATEX flameproof with increased safety, K7 IECEx) against the plant classification.
• Decide on DA1/DA2 diagnostics, the AX discrete channels, the LOI display and the cable kit length before ordering.

Installation, commissioning and maintenance of the 8732EM

Mount the sensor in a full pipe with a minimum of five straight diameters upstream and two downstream of the electrode plane, and make sure the process fluid is grounded: use grounding rings, a reference electrode or lining protectors as the application requires. Earth the transmitter to the plant earth, kept separate from the process reference ground. Before any welding on the pipe, remove all electrical connections from sensor and transmitter. Enter the 16-digit sensor calibration number, set the pipe size and span, then run the empty-pipe and grounding diagnostics during commissioning. The quick start guide states a five-minute warm-up to rated accuracy after power-up.

Maintenance is mostly electrical: check cable glands and cover O-rings, inspect for moisture at the terminals, and keep spare AC or DC fuses (2 A quick-acting for AC, 3 A for DC). Do not connect a Rosemount transmitter to a non-Rosemount sensor in an Ex area, and do not rub non-metallic labelled units with a dry cloth because of electrostatic charge.

Typical applications in Oman and the GCC

Magnetic transmitters of this class are used on seawater intake and brine lines in desalination plants, cooling-water circuits in power stations, produced and injection water in oil and gas fields, effluent and sewage treatment, and chemical dosing duties in petrochemical sites. The –50 to +60 °C ambient range, IP66/67 enclosure and optional offshore marine paint (V2) suit exposed outdoor installations with heat, dust and salt air. Abrasive slurries are normally kept to 0.9 to 3.1 m/s and clean liquids to 0.6 to 6.1 m/s, according to the platform sizing guide.

8732EM output and power options compared

Information to send with an RFQ for 8732EM

• Full model code or the options above, including mounting style, supply, output and conduit thread.
• Sensor type and size if you need a complete flow meter (8705, 8711 or 8721), with liner, electrode material and flange rating.
• Process liquid, conductivity, temperature, pressure and flow range in m3/h.
• Hazardous-area classification and required certificate scheme.
• Cable length for remote mounting and the control system protocol.
• Quantity and delivery site in Oman or the GCC.

Documents and quotation

A manufacturer quick start guide for the 8732EM with HART protocol is attached on this page. Send us the model code and we will confirm availability and any further documents for your 8732EM requirement.