FMR540 Radar Tank Gauge

FMR540 Radar Tank Gauge

The FMR540 Radar Tank Gauge (RTG), with an accuracy rate of ± 1 mm, is a smart radar tank gauge for continuous and non-contact level measurement.

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Accuracy Approved for Custody Transfer

2 wire radar diagramThe FMR540 RTG, with an accuracy rate of ± 1 mm, is used for custody transfer and inventory control applications with NMi- and PTB-approvals and meets the requirements according to OIML R85 and API 3.1B. The parabolic antenna is particularly suited for free space applications up to 40m.



Touch Screen Operations

Easy onsite operation using built-in touch control display without having to open the enclosure. It also has a user friendly operating menu.



Worldwide Approvals

This radar gauge is approved for use in explosion hazardous areas to IEC Ex,  ATEX and WHG standards. It is also SIL 2 certified for overfill prevention.



Key Features

  • 4-wire technology: HART and 24 V DC intrinsically safe power supply.
  • Non-contact measurement: Tank top is almost independent from product properties.
  • Horn antenna: DN100 (4″).
  • Parabolic antenna: DN200 (8″) or DN250 (10″).
  • Integrate into existing tank gauging systems using the 4590 Tank Side Monitor
  • Easy onsite operation using built-in display.
  • Easy commissioning and diagnostics using Windows® based software.
  • HART, PROFIBUS PA or FOUNDATION Fieldbus protocols.
  • Integrated air purge prevents antenna clogging.
  • Alignment device provides optimum alignment of antenna/radar beam to the liquid surface
  • High temperatures: Suitable for process temperatures up to -40 to +200°C (-40 to +392°F).
  • High pressure: Suitable from Vacuum to +16bar (+232psi).
  • Approved for use in hazardous locations.
  • SIL 2 approved for overspill protection applications.

6 kg (13.23 lbs) plus flange weight


IP65/68, NEMA 4X/6P (IP20, NEMA 1 with open
housing and removed liquid crystal display)
Housing F23: 316L, corrosion-resistant steel
Housing F12/T12: aluminum, seawater repellent,
chromate, powder coated


-40°F to 176°F (-40°C to 80°C)


Better than ± 1mm
Horn antenna: 30 m (98 ft)
NMi and PTB 15 m (49 ft)
Parabolic antenna: 40 m (131 ft)
NMi = 25 m (82 ft), PTB = 30 m (98 ft)

Power Consumption

Maximum 400 mW at 16 V
Maximum 600 mW at 24 V
Maximum 750 mW at 30 V
Non-Ex: max. 900 mW at 36 V


IP65/68, NEMA 4X/6P

Operating Frequency

K-band 26 GHz, Up to 8 RTGs can be installed in the same tank

See specifications document for more information.

Approvals & Certifications

IEC Ex,  ATEX and WHG approvals

SIL2  certification


Horn or parabolic – Various sizes and material types

Process Connections
  • ANSI, DN, JIIS, JPI and UNIflange
  •  Gas-tight feed through
Output Options


Gland Entry

Metric, NPT, G

Contact Varec for more information or see technical specifications.


Radar Gauge Comparison Guide
Easy-to-follow guide that compares the FMR532, FMR50, FMR51, FMR52, FMR53, FMR54, FMR540, FMR60, FMR62, NMR81 and NMR84 radar gauges.

White Paper

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Application Checklists

Radar Tank Gauging Checklist
Checklist for Radar Tank Gauging needs.
Temperature Tank Gauging Checklist
Checklist for Temperature Tank Gauging needs.


Advanced Tank Gauging
High Accuracy Inventory Management and Custody Transfer Applications
Inventory Control Solutions
Integrate Field Instruments and Software for Complete Asset Management

Technical Specifications


FMR540 Radar Tank Gauge Manual
Please visit the Endress and Hauser website to access the parts and accessories information for the FMR540 Radar Gauge.
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