Endress+Hauser Micropilot FMR54 Free-Space Radar Level Transmitter

The Endress+Hauser Micropilot FMR54 is a continuous, non-contact free-space radar level transmitter for liquids, pastes and sludges. Because the measurement is based on the time-of-flight of a microwave pulse reflected from the product surface, it is unaffected by changing density, temperature swings, gas blankets or vapors above the medium.

The FMR54 is the high-temperature / high-pressure member of the classic Micropilot F-series. With the appropriate seal and process separation it covers a process temperature range of –196 to +400 °C (–321 to +752 °F) and a process pressure range of –1 to +160 bar (–14.5 to +2320 psi), which makes it suitable for reactors, distillation columns, high-pressure separators and other demanding vessels. Operating in C-band (~6 GHz), it reaches a maximum measuring range of 20 m (66 ft) with a horn antenna, or 38 m (125 ft) with a planar antenna in a stilling well, at a reference accuracy of ±6 mm (0.24 in) over the entire range.

The device is offered with a horn antenna (80 to 250 mm / 3 to 10 in) or a planar antenna (150 to 300 mm / 6 to 12 in). The planar antenna is particularly suited to stilling-well applications and does not depend on the alignment or geometry of standard stilling wells. Wetted parts (horn, flange, process separation) are 316L stainless steel with PTFE or Al2O3 separation and a choice of FKM (Viton), FFKM (Kalrez), EPDM or graphite seals, so the instrument can be matched to aggressive, hot or high-pressure media.

Electronically the standard version is a 2-wire, 4–20 mA HART loop-powered transmitter; PROFIBUS PA and FOUNDATION Fieldbus versions and an optional switch output are available, together with Bluetooth commissioning through the SmartBlue app. Reliability features include Multi-Echo Tracking, HistoROM data management and Heartbeat Technology. The FMR54 carries international hazardous-area approvals (ATEX, IECEx, FM, CSA, NEPSI, INMETRO, JPN Ex), IP68/NEMA6P protection, WHG overfill prevention and functional safety up to SIL 3 (homogeneous or diverse redundancy) per IEC 61508. All figures are quoted verbatim from Endress+Hauser Technical Information TI01041F.