Endress+Hauser FMR67B Micropilot Radar for Bulk Solids

FMR67B Micropilot radar for silos and bulk solids

The Endress+Hauser FMR67B is a Micropilot free-space radar transmitter for continuous, non-contact level measurement of powdered to granular bulk solids. It looks down onto the material from the top of a silo, bunker or stockpile hall and reports the distance to the surface, which the device converts to level, volume or any other linearised value. The FMR67B is the long-range, high-temperature member of the Micropilot family, with a measuring range up to 125 m and a process temperature range of –40 to +450 °C.

Three antenna styles are covered by the datasheet: a 65 mm stainless 316L horn with a ceramic (Al₂O₃) seal and graphite gasket, a 50 mm PTFE drip-off antenna, and an 80 mm PTFE flush-mount antenna. The narrow beam of the horn version, with a 4 degree beam angle, lets the FMR67B ignore much of the clutter that disturbs wider-beam radars in storage vessels with internal fittings.

FMR67B technical specifications

How the FMR67B measures through dust

The antenna sends a microwave signal whose frequency is swept continuously, and the reflection from the product surface returns with a small frequency difference proportional to the distance. Because the evaluation uses this frequency difference, the FMR67B stays stable when the material surface is rough, sloped or covered with dust. The high frequency also focuses the beam strongly, which is why the 65 mm horn can look past struts, ladders and cables that would give false echoes with a lower-frequency radar.

The measuring range ends where the beam meets the silo floor, so conical outlets can hide the lowest part of the stockpile. For this reason the datasheet offers UNI flanges with an integrated alignment unit for the horn antenna, which lets you tilt the antenna axis by up to 15 degrees in any direction and aim the beam at the discharge cone. The recommended end of the measuring range is 10 mm before the antenna tip to avoid damage from abrasive material and build-up.

Antenna, connection and nozzle selection for FMR67B

Choosing the antenna is the most important decision when ordering an FMR67B. The table summarises the three designs in the datasheet.

Maximum nozzle length also depends on the antenna. For the 65 mm horn the datasheet allows a nozzle of up to 1,700 mm for a 80 to 100 mm bore, 2,100 mm for 100 to 150 mm and 3,200 mm above 150 mm; the nozzle end must be smooth, rounded and free of burrs, and a mapping of interference echoes is required. Always mount the FMR67B at least 20 cm from the wall and away from the filling curtain.

Where the FMR67B fits in the plant

The FMR67B sits in the Micropilot range between the compact FMR20B and FMR30B units, which are 80 GHz radars for water, utilities and tanks with plastic antennas and a 30 m range, and the higher-end process radars. For bulk material it is the long-range option: cement and clinker silos, fly ash and lime storage, grain and sand bunkers, coal and aggregate stockpiles. It communicates on PROFIBUS PA, so a segment coupler and a PA-capable control system are needed; the supply is not polarity sensitive and the device is FISCO/FNICO compliant for intrinsically safe segments.

Accessories listed for the family include weather protection covers in 316L (XW112) or plastic (XW111), an adjustable flange seal, the FHX50B remote display, a gas-tight feedthrough and the RID14 and RID16 field displays. Field Xpert SMT70 and the Fieldgate SFG500 are listed as operating and remote-access options.

FMR67B selection and ordering checklist

• Material and its dielectric constant, particle size, dust level and angle of repose.
• Silo height, nozzle diameter and length, and whether the discharge cone needs the alignment unit.
• Maximum process temperature and pressure, which sets antenna, seal and flange.
• Housing type: plastic, aluminum, 316L hygiene, dual-compartment or L-shaped, and cable entry thread.
• Communication and power: PROFIBUS PA segment, Ex i or Ex d/e approval, optional overvoltage protection.
• Purge air thread (NPT 1/4 or G 1/4) for dusty applications, weather cover and remote display.
• Optional Heartbeat Verification + Monitoring package and Bluetooth display.

Installing and commissioning the FMR67B

Mount the radar so the antenna axis is perpendicular to the product surface; the datasheet notes that tilting can reduce range or create false echoes unless the alignment unit compensates. Keep heating coils, baffles and level switches out of the beam, and use metal deflector plates to scatter interfering reflections. Shade the housing from direct sun in hot climates and route cables downward with a drip loop so water cannot enter the terminal compartment.

Commissioning is guided by wizards: enter the empty and full distances, run an interference-echo mapping on the empty or low silo, and set the linearisation. Preprogrammed curves cover pyramid, conical and angled bottoms, horizontal cylinders and spheres, and up to 32 points can be entered manually. With the Heartbeat Verification + Monitoring package the device can run an on-demand verification test with a traceable passed or failed report, and it offers foam and build-up detection wizards that help plan cleaning before the signal is lost.

FMR67B applications in Oman and the GCC

In the Gulf region the FMR67B suits cement plants, mineral processing, power plant coal and ash handling, fertiliser and petrochemical granule storage, and port bulk terminals. Ambient heat, airborne dust and sand ingress make a rugged IP66/68 housing, purge air and a high-temperature antenna practical rather than optional. The ceramic-sealed horn is relevant wherever product and wall temperatures are high. Seven Star LLC supplies Endress+Hauser instruments as an independent supplier in Muscat to operators and EPC contractors across Oman and the GCC.

Information to send with an FMR67B RFQ

• Full order code or nameplate photo of the existing FMR67B, if you are replacing a unit.
• Product name, grain size, moisture, dielectric constant if known, and fill method.
• Silo diameter, height, nozzle size, flange standard and rating.
• Process temperature, pressure, dust level and need for purge air.
• Communication protocol, hazardous area classification and required approvals.
• Quantity, cable entries and any Heartbeat or Bluetooth options.

Documents and quotation

The Endress+Hauser Technical Information for the FMR67B PROFIBUS PA version is attached on this page as a datasheet, with dimensions, ordering structure and installation guidance. Please read the nozzle and antenna sections before choosing options.

Send us your application data and the FMR67B order code you need, and we will prepare a quotation for delivery in Oman and the GCC.