Radar (FMCW) level transmitter for liquids in narrow tanks with internal obstructions

  • Continuous, non-contact level measurement in small and narrow tanks with agitators as well as long nozzles
  • 80 GHz radar, flush-mounted Lens antenna
  • Measuring range: 0…100 m / 328 ft
  • -50…+200°C / -58…+392°F; -1…40 barg / -14.5…580 psig
  • Icon/Logo for 80 GHz radar level measurement
  • Icon/Logo Security Integrity Level 2/3 (SIL 2/3)

OPTIWAVE 7500 with DN40 / 1½" PEEK Lens antenna

OPTIWAVE 7500 – 80 GHz radar (FMCW) level transmitter for liquids in narrow tanks with internal obstructions

The OPTIWAVE 7500 is a 2-wire 80 GHz radar (FMCW) level transmitter for demanding liquid applications involving narrow tanks with long nozzles and internal obstructions like agitators or heating coils. Its very small beam angle and negligible dead zone make this FMCW radar the optimal choice for continuous, non-contact level measurement in both extremely small and very high tanks (up to 100 m / 328 ft). The level transmitter is even able to measure through tank roofs made of non-conductive materials. Its PEEK and PTFE Lens antennas are insensitive to deposits and well suited for corrosive environments. As the antennas are flush-mounted, there is no intrusion into the tank.

The OPTIWAVE 7500 provides accurate readings even in processes with fast changing levels. It can be used in operating temperatures of up to +200°C / +392°F and pressures up to 40 barg / 580 psig. This level transmitter offers a wide range of flange and thread connections (starting from ¾″). It comes with approvals for use in hazardous areas as well as extensive device diagnostics (acc. to NE 107) and HART®7 communication.

Product highlights

  • 2-wire, loop-powered, with HART®7
  • Flush-mounted PEEK or PTFE Lens antennas (no tank intrusion)
    • Insensitive to deposit
    • Small dead zone and beam angle (4° with DN70 / 2¾″ Lens antenna)
    • PEEK or PTFE flange plate protections as well as a PEEK thread protection for corrosive media
    • 112 mm / 4.4″ antenna extension for long nozzles
  • Empty tank spectrum function eliminates false reflections caused by tank internals
  • ±2 mm / ±0.08″ accuracy
  • Large range of flange and thread connections
  • Large, backlit LCD screen with 4-button keypad for operation with bar magnet; no need to open the housing cover
  • PACTware™, HART® DD and DTM provided free of charge with full functionality
  • Extensive device diagnostics acc. to NAMUR NE 107
  • SIL 2/3 certified for safety-related applications
  • 3-year warranty

Typical applications


  • Level measurement in small and narrow tanks with internal obstructions (e.g. heating coils, agitators etc.)
  • Level measurement in tanks with long nozzles
  • Measurement through tank roofs made of non-conductive material (e.g. plastic, fibreglass or glass)
  • Processes with fast changing levels (≤60 m/min / 196.85 ft/min)

Chemical industry

  • Solvents, acids
  • Foaming agents
  • Fertiliser (e.g. urea)
  • Chlorine
  • Resins
  • Paint, ink
  • Corrosion inhibitors

Petrochemical industry, oil and gas industry

  • Liquefied Petroleum gas (LPG)
  • Hydrocarbons
  • Slop oil
  • Drilling mud
  • Ethylene
  • Lubricant oil

Power industry

  • Hydrocarbons
  • Lime milk

Accessories for this product


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)

View product details
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

Purge port connection with G1 1/2 thread

Purge port connection

Purging system for OPTIWAVE level transmitters 

  • Special purge kit thread with holes
  • For compressed air or water cleaning of level radar antennas
  • Suitable for radars with G1½, G3, 1½ NPT and 3 NPT process connections
  • Can be additionally equipped with an antenna aiming kit

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


General information

Measurement principleRadar
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-1…40 barg/
-14.5…580 psig
Pressure ratingsEN (1092-1): PN40
ASME (B 16.5): Cl 300#
JIS (B 2220): 10k
Process temperature-50…+200°C/
Wetted partsAustenitic stainless steel (1.4404/316L), Polyetheretherketone (PEEK), Polytetrafluoroethylene (PTFE)
GasketsEthylene propylene diene monomer (EPDM), Fluoroelastomer rubber (FKM/FPM), Kalrez® 6375
Accuracy (liquids)±2 mm/
±0.08 in


Certificates/Approvals ExATEX, cQPSus, EAC Ex, IECEx, KCs, NEPSI
Certificates/Approvals SafetySIL 2/3
Certificates/Approvals MarineDNV
Certificates/Approvals OthersCRN / ASME B31.3, NACE, WHG
Ingress protectionIP66/68, NEMA4X/6P
NAMUR complianceNE 107, NE 21, NE 43, NE 53


Digital outputsFOUNDATION™ fieldbus, HART®, Profibus-PA
Analogue outputs4…20 mA

Process connections

Flange connectionsEN (1092-1): DN50…200
ASME (B 16.5): 2…8"
JIS (B 2220): 50…200A
Thread connectionsMale:
G¾, G1, G1½, G3
¾ NPT, 1 NPT, 1½ NPT, 3 NPT