Radar (FMCW) level transmitter for liquids with hygienic requirements

  • Continuous, non-contact level measurement in small and narrow vessels, small storage tanks and agitated tanks
  • 80 GHz radar, flush-mounted Lens antenna
  • Measuring range: 0…50 m / 164 ft
  • -40…+150°C / +302°F; -1…25 barg / -14.5…362 psig
  • Icon/Logo for 80 GHz radar level measurement
  • Icon/Logo Security Integrity Level 2/3 (SIL 2/3)

OPTIWAVE 3500 with DN25 / 1" PEEK Lens antenna and clamp connection

OPTIWAVE 3500 C – 80 GHz radar (FMCW) level transmitter for liquids  hygienic applications

The OPTIWAVE 3500 is a 2-wire 80 GHz radar (FMCW) level transmitter for liquids in hygienic applications. It is designed for continuous, non-contact level measurement in the food and beverage as well as pharmaceutical industry. The device features a flush-mounted PEEK Lens antenna with a small beam angle and dead zone for precise measurement even in small and narrow tanks with agitators. It is equally suited for use on larger tanks, measuring distances of up to 50 m / 164 ft.

The OPTIWAVE 3500 fits applications with any finished or raw product – from raw milk, wine or juice to solvents. As the radar withstands process temperatures up to +150°C / +302°F and pressures up to 25 barg / 362 psig, it can be used in CIP/SIP cleaning operations. The OPTIWAVE 3500 offers a large choice of hygienic process connections. It comes with extensive device diagnostics (acc. to NE 107) as well as HART®7 communication.

Product highlights

  • 2-wire, loop-powered, with HART®7
  • Flush-mounted PEEK Lens antenna (no tank intrusion)
  • Small dead zone and beam angle (8° with DN40 / 1½″)
  • ± 2 mm / ±0.08” accuracy
  • Empty tank spectrum function eliminates false reflections caused by tank internals
  • Suitable for SIP (Sterilisation In Place) and CIP (Cleaning In Place)
  • Large choice of hygienic process 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
  • Conform to FDA, EC1935/2004, EC2023/2006, EU 10/2011 and EHEDG
  • SIL 2/3 certified for safety-related applications
  • 3-year warranty

Typical applications


  • Hygienic level applications with finished and raw products
  • For small and narrow tanks, small storage tanks and agitated tanks
  • Processes with fast changing levels (≤60 m/min / 196.85 ft/min)

Food and Beverage Industry

  • Fruit extract
  • Beverages (soft drinks, beer, wine, fruits juices, spirits etc.)
  • Yeast
  • Raw milk, cheese and other dairy products
  • Chocolate
  • Molasses
  • Soup
  • Vegetable oil
  • CIP media (incl. slightly corrosive acids and caustic solutions)

Pharmaceutical Industry

  • Purified and sterilised water
  • Vaccine intermediates
  • Solvents, alcohols, bases
  • Slightly corrosive acids

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


General information

Measurement principleRadar
Level measurement typeContinuous measurement
Measured mediaLiquids, Pastes, Slurries
Contact to measured mediumNo
Interface measurementNo
Measuring range (liquids)0…50 m/
0…164 ft
Process pressure-1…25 barg/
-14.5…362 psig
Process temperature-40…+150°C/
Ambient temperature-40…+80°C/
Wetted partsAustenitic stainless steel (1.4404/316L), Polyetheretherketone (PEEK)
Accuracy (liquids)±2 mm/
±0.08 in


Certificates/Approvals ExATEX, cQPSus, EAC Ex, IECEx, NEPSI
Certificates/Approvals SafetySIL 2/3
Certificates/Approvals HygienicEC 1935/2004, EC2023/2006, EHEDG, EU 10/2011, FDA
Certificates/Approvals OthersCRN / ASME B31.3, 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

Hygienic connectionsDairy screw (DIN 11851): DN40, DN50
Varivent®: N
SMS (1145): 51 mm
Tri-Clamp®: 1½″, 2″
Clamp (ISO 2852): 25, 33.7, 38, 40, 51
NEUMO BioControl®: DN50
Aseptic screwed union (DIN 11864-1A): DN40, DN50