Radar (FMCW) level transmitter for agitated and corrosive liquids

  • Continuous, non-contact level measurement in harsh environments
  • 24 GHz radar, Horn or Drop antennas
  • Measuring range: 0…100 m / 328 ft
  • -50…+200°C / -58…+390°F, up to +700°C / +1292°F with special version (on request); -1…100 barg / -14.5…1450 psig (higher on request)

OPTIWAVE 7400 – Version with Drop antenna and thread connection

Radar (FMCW) level transmitter OPTIWAVE 7400 – Version with Drop antenna and thread connection

The OPTIWAVE 7400 is a 2-wire 24 GHz radar (FMCW) level transmitter for liquids in harsh environments like tanks with agitators containing corrosive media. It is particularly designed for continuous, non-contact level measurement under extreme conditions prevalent in the chemical, petrochemical or oil and gas industry. The device features Metallic Horn antennas as well as PTFE and PEEK Drop antennas for measuring distances up to 100 m / 328 ft. The Drop antennas are perfectly suited for aggressive liquids in tanks. In applications with toxic and dangerous products, this radar device can be equipped with a Metaglas® second sealing barrier.

The OPTIWAVE 7400 provides accurate readings even in processes with fast changing levels. It has approvals for hazardous areas and can be used in process conditions of up to +200°C / +392°F and 100 barg / 1450 psig. There is also a dedicated version available for non-ex applications with molten salt or other high temperature liquids of up to +700°C / +1292°F. The radar level transmitter comes with a quick coupling system, allowing the housing to be removed under process conditions. The device features extensive device diagnostics (acc. to NE 107) as well as HART®7 communication.

Product highlights

  • 2-wire, loop-powered, with HART®7
  • Also available as special version for non-ex applications with molten salt or other high temperature liquids of up to +700°C / +1292°F
  • PTFE or PEEK Drop antenna:
    • Small beam angle (4° with DN150 / 6” PTFE antenna)
    • Ellipsoidal shape and smooth surface to minimise scaling
    • Flange protection against corrosive media
    • New DN100 / 4" Drop antenna for distances up to 80 m / 262.5 ft
  • 1.4404 / 316L metallic Horn antenna:
    • DN200 / 8" antenna for distances up to 100 m / 328 ft
    • Optional purging system
    • Heating / cooling systems to prevent crystallisation
  • ± 2 mm / 0.08” accuracy
  • Can measure in processes with fast changing levels (≤60 m/min | 196.85 ft/min)
  • Metaglas® second sealing barrier for toxic and dangerous products
  • Antenna extensions to suit any nozzle length
  • Flange or thread connections
  • Quick Coupling system permits removal of the converter under process conditions and 360°rotation for easy reading of display
  • Converter backwards-compatible with all OPTIWAVE 7300 C flange systems
  • Large, backlit LCD screen with 4-button keypad for operation with bar magnet; no need to open the housing cover
  • PACTware™, HART® DDs and DTMs provided free of charge with full functionality
  • Extensive sensor and process diagnostics (incl. NE 107)
  • 3-year warranty

Typical applications


  • Level measurement in/on storage, process or batch tanks and reactors (max. 100 m / 328 ft)
  • Agitated liquids in tanks
  • Processes with fast changing levels (≤60 m/min / 196.85 ft/min)
  • High accuracy applications where ±2 mm / 0.08¨ is specified

Chemical industry

  • Alcohols, e.g. methanol, ethanol
  • Solvents, acids, bases
  • Additives
  • Butadiene
  • Ethylene, propylene
  • Molten sulphur

Petrochemical industry, oil and gas industry

  • Liquefied gases
  • Hydrocarbons and fuels
  • Benzene
  • Hydraulic oils
  • Condensates

Power industry

  • Molten salt at Concentrated Solar Power plants (CSP)

Iron, steel and metal industry

  • Molten steel batching

Accessories for this product

OPTICHECK Master Verification tool


Handheld for in-depth verification, device commissioning and monitoring

  • On-site performance check and verification (level 0,1,2) without process interruption
  • Convenient commissioning of field devices, e.g. zero calibration
  • Detailed reports for proof test documentation of safety loops acc. to IEC 61508/61511, and for quality management systems (ISO 9001)
Wall-mounted bracket

Wall-mounted bracket

Antenna aiming kit for OPTIWAVE level transmitters

  • L-shaped bracket to attach radar level transmitters firmly to a wall
  • Only suitable for radars with G1 or G1½ process connection
  • Material: Stainless steel (1.4404 / 316L)
  • Bracket length: 250mm / 9.84”
Hanging bracket

Hanging bracket

Antenna aiming kit for OPTIWAVE level transmitters

  • Orientable bracket to position a radar level transmitter at any angle up to a 45° angle
  • To direct the beam angle of the radar into the correct part of a tank, silo or stockpile
  • Material: stainless steel (1.4404 / 316L)
  • EPDM sleeve for increased grip of the radar
Low pressure flange disc

Low pressure flange disc

Process connection for OPTIWAVE level transmitters

  • Stainless steel disc to enable firm and even installation of level radars into onto tanks and silos
  • Suitable for radars with G1, G1½, G3, 1 NPT, 1½ NPT or 3 NPT process connections
  • Available in sizes DN50…DN200 / 2…8”
  • Low pressure conditions only: max. 1 barg at 20°C / 14.50 psig at +68° F

Technical data

Measurement principlesRadar
Level measurement typeContinuous measurement
Measured mediaLiquids, Pastes, Slurries
Contact to measured mediumNo
Interface measurementNo
Measuring range (liquids)0…100 m/
0…328 ft
Process pressure (relative)-1…100 barg/
-14.5…1450 psig
Pressure ratingsEN (1092-1): PN100
ASME (B 16.5): Cl 1500#
JIS (B 2220): 10k
Process temperature-50…200°C/

Special version (on request):
Up to +700°C/+1292°F
Ambient temperature-40…80°C/
Wetted partsAustenitic stainless steel (1.4404/316L), Polyetheretherketone (PEEK), Polytetrafluoroethylene (PTFE)
Process sealsEPDM, FKM/FPM, Kalrez® 6375
Accuracy (liquids)±2 mm/
±0.08 in


Certificates/Approvals ExATEX, cQPSus, EAC, IECEx, NEPSI
Certificates/Approvals OthersCRN, NACE, WHG
Ingress protectionIP66/68, NEMA4X/6P
NAMUR complianceNE 107, NE 21, NE 43, NE 53


Digital outputsHART®
Analogue outputs4…20 mA

Process connections

Flange connectionsEN (1092-1): DN40…200
ASME (B 16.5): 1…8"
JIS (B 2220): 40…200A
Thread connectionsMale:
1 ½NPT