Radar (FMCW) level transmitter for powders and dusty atmosphere

  • Continuous, non-contact level measurement in high and narrow silos, hoppers or containers
  • 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 6500 – Version with DN70 PEEK Lens antenna and thread connection

Radar (FMCW) level transmitter OPTIWAVE 6500 – Version with Lens antenna and thread connection

The OPTIWAVE 6500 is a 2-wire 80 GHz radar (FMCW) level transmitter for demanding applications with powders in very dusty atmospheres. With its small beam angle, this radar is particularly suited for continuous, non-contact level measurement in high and narrow silos, hoppers or buffer storage containers up to 100 m / 328 ft. Due to specific algorithms and the high signal dynamics of the FMCW radar, the level transmitter is ideal for low-reflective media, dust, uneven surfaces or silos with internal obstructions. As it features flush-mounted PEEK and PTFE Lens antennas, there is no intrusion into the tank.

The OPTIWAVE 6500 provides accurate and reliable readings in process conditions with temperatures up to +200°C / +392°F and pressures up to 40 barg / 580 psig. It offers flange or thread connections as well as an optional 112 mm / 4.4" antenna extension for the DN40 / 1.5″ antenna. Approvals for use in hazardous areas are also available. It comes with extensive device diagnostics (acc. to NE 107) and HART®7 communication.

Product highlights

  • 2-wire, loop-powered, with HART®7
  • High dynamics for clear vision despite dusty atmospheres or low reflective media
  • Empty tank spectrum function eliminates false reflections caused by tank internals
  • Flush-mounted PEEK or PTFE Lens antennas (no tank intrusion):
    • DN70 / 2¾″ with 4° beam angle for distances up to 100 m / 328 ft
  • 112 mm / 4.4" antenna extension for long nozzles
  • Unaffected by angle of repose
  • Purging system for antenna cleaning
  • ±2 mm / ±0.08″ accuracy
  • Large choice of flange and thread connections
  • Low-cost 316L low-pressure flange discs
  • 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 high and narrow silos with internal obstructions, buffer silos, bulk storage containers, hoppers
  • Processes with fast changing levels (≤60 m/min / 196.85 ft/min)

Minerals and mining industry

  • Fine powders (e.g. building materials)
  • Sand
  • Cement
  • Gypsum
  • Lime
  • Filler
  • Fly ash
  • Coal dust

Chemical industry

  • Plastic powder
  • Silica
  • Soap powder

Food and beverage industry

  • Milk powder
  • Coffee powder
  • Chocolate powder
  • Flour
  • Starch
  • Salt, sugar

Power industry, iron, steel and metal industry

  • Coke and coal dust

Pulp and paper industry

  • Saw dust

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
Slanted flange

Slanted flange

Antenna aiming kit for OPTIWAVE 6400 and OPTIWAVE 6500 level transmitters

  • With slight slope (2° angle) for antenna or lens adjustment
  • To direct the beam angle of the radar into the optimal correct part of a silo
  • Material: PP (max. +100°C / +212°F) or PTFE (max. +150°C / +392°F)
  • Available in different sizes: DN80…150 / 3…8”

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

Orientation system

Orientation system

Antenna aiming kit for OPTIWAVE level transmitters

  • Orientable system with low pressure flange disc
  • To direct the beam angle of the radar into the optimal part of a tank, silo or stock pile
  • Material: stainless steel (1.4404 / 316L)
  • Various sizes for G1½, G3, 1½ NPT and 3 NPT process connections

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


Technical data

Measurement principlesRadar
Level measurement typeContinuous measurement
Measured mediaGranulates, Powders, Solids
Contact to measured mediumNo
Interface measurementNo
Measuring range (solids)0…100 m/
0…328 ft
Process pressure (relative)-1…40 barg/
-14.5…580 psig
Pressure ratingsEN (1092-1): PN40
ASME (B 16.5): Cl 300#
JIS (B 2220): 10k
Ambient temperature-40…+80°C/
Wetted partsAustenitic stainless steel (1.4404/316L), Polyetheretherketone (PEEK), Polytetrafluoroethylene (PTFE)
Process sealsEthylene propylene diene monomer (EPDM), Fluorocarbon-based synthetic rubber (FKM/FPM), Kalrez® 6375
Accuracy (solids)±2 mm/
±0.08 in


Certificates/Approvals ExATEX, cQPSus, EAC Ex, IECEx, KCs, NEPSI
Certificates/Approvals SafetySIL2/3
Certificates/Approvals MarineDNV
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

Flange connectionsEN (1092-1): DN50…200
ASME (B 16.5): 2…8"
JIS (B 2220): 50…200A
Thread connectionsMale:
G1½, G3
1 ½ NPT, 3 NPT