Endress+Hauser Micropilot FMR57 Radar Level Transmitter — Bulk Solids

The Endress+Hauser Micropilot FMR57 is a free-space, non-contact radar level transmitter built for the highest demands in bulk-solids level measurement. Working on the time-of-flight principle in the K-band at approximately 26 GHz, it continuously measures the distance to the material surface and derives level in tall silos, bunkers, stockpiles and bins that hold powdery to granular solids such as cement, clinker, grain, plastic pellets, sand, ores and fertiliser.

Because the microwave signal is virtually unaffected by dust, filling noise, temperature stratification and gas blankets, the FMR57 keeps measuring where mechanical and many other level technologies struggle. It reaches a maximum range of 70 m (230 ft) with a reference accuracy of ±3 mm, and because the transmitter pulses are statistically coded, up to eight Micropilot devices can operate in the same vessel without interfering with each other.

The sensor is offered with a horn antenna (DN80/3", DN100/4") or a focusing parabolic antenna (DN200/8", DN250/10") that generates a very narrow beam angle for slim, high silos. An integrated alignment device lets the antenna axis be tilted up to 15° toward the sloping solids surface, while an optional air-purge connection keeps the antenna clean in heavily dusting or build-up-forming media. Wetted parts are 316L with a PEEK process-separation cone (PI for high temperature) and FKM/PTFE seals; process temperature covers –40 to +400 °C and process pressure –1 to +16 bar.

Electrically the transmitter delivers a 4–20 mA HART signal over a 2-wire loop (PROFIBUS PA and FOUNDATION Fieldbus versions are also available), sits in a robust 316L GT18 field housing rated IP68, and supports functional safety up to SIL2 per IEC 61508 (SIL3 in homogeneous/heterogeneous redundancy) with ATEX, IECEx, FM and CSA hazardous-area approvals. The exact unit documented here carries order code FMR57-1218/0 (extended order code FMR57-BFACCABDA6XCJ1+), 12–35 V DC 2-wire supply, FKM/PEEK/316L materials and IP68/66 protection.